Category Archives: Programming Language

Linq to DataSet

1.数据集( DataSet ) 　　• DataSet 是更为广泛使用的ADO.NET 组件之一，它可以显式缓存不同数据源中的数据。　　• 在表示层上DataSet 与GUI 控件紧密集成，以进行数据绑定。　　• 在中间层上，它提供保留数据关系形状的缓存并包括快速简单查询和层次结构导航服务，从而可以减少对数据库的请求数。 2.查询数据集　　• DataSet 虽然具有突出的优点，但其查询功能也存在限制。　　• Select 方法可用于筛选和排序，GetChildRows和GetParentRow 方法可用于层次结构导航。　　• 但对于更复杂的情况，开发人员必须编写自定义查询。这会使应用程序性能低下并且难以维护。 3.使用LINQ to DataSet 　　• 使用LINQ to DataSet 可以更快更容易地查询在DataSet 对象中缓存的数据。　　• 这些查询用编程语言本身表示，而不表示为嵌入在应用程序代码中的字符串。　　• LINQ to DataSet 可使Visual Studio 开发人员的工作效率更高，　　　　因为Visual Studio IDE 提供编译时语法检查、静态类型化和对 LINQ 的智能感知的支持。　　• LINQ to DataSet 也可用于查询从一个或多个数据源合并的数据这可以使许多需要灵活表示和处理数据的方案能够实现。 4.查询数据集　　 • 填充DataSet 　　　　– XxxDataAdapter 　　　　– LINQ to SQL 　　 •主要使用下面两个扩展类　　　　– DataRowExtensions 　　　　– DataTableExtensions 　　• 查询支持　　　　– 类型化数据集　　　　– 非类型化数据集 5.启用LINQ to DataSet 功能　　• 要求.NET Framework 3.5 　　• 引用System Data DataSetExtensions 程序集 […]

龙生 11 Sep 2012

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LinQ&EF任我行（一）--LinQ to SQL （转)

LinQ家族五大成员：LinQ to Objects – 默认功能，用来实现对内存中集合对象的查询LinQ to SQL – 针对SQL Server的查询，它是一个带有可视化的操作界面的ORM工具LinQ to DataSet – 对强类型化或弱类型化的DataSet或独立的DataTable进行查询LinQ to Entity – 对实体框架中EDM定义的实体集合进行查询。LinQ to XML – 对XML文档进行查询创建等操作。 C#语法与LinQ相关的新增功能 1.隐式强类型变量在C#3.0中可以使用var关键字隐式定义强类型局部变量。《图1》这里的var关键字定义变量与JavaScript定义变量看起来很像但二者有着本质的区别。JavaScript定义的变量是弱类型的变量，也可理解为是一种通用类型的变量，它可以容纳各种类型的值，还可以在运行过程中动态修改其中的内容类型。下面这种写法在JavaScript中是正确的：var obj = 3.14;obj = "hello world";C#中的var则是种强类型的变量，它在定义的时候会确定数据类型，分配内存空间。上面这两名代码在C#3.0中会报错，因为第一句已经把obj定义为double型的变量，第二句把字符串赋值给double是错误的操作。隐式强类型并不能有效简化我的书写的代码，但当我们在用它来动态接收一些未知类型的数据的时候就显虽得很强大。在隐式强类型变量出现前，我们一般是使用object型变量来接收这种未知类型的数据的。 2.对象初始化这个功能可以有效简化类的getter和setter部份的代码，还可以只使用一行表达式语句实现对象的实例化与初始化操作。如定义实例类时可以使用如下代码，没有必要再把成员变量和属性分别定义了。public class LineItem{ public int OrderID { get; set; } public int ProductID { get; set; } public short Quantity { get; set; } public string QuantityPerUnit { get; set; } public decimal UnitPrice { get; set; } public float Discount { get; set; }} 实例化LineItem对象，并为它赋值var line3 = new LineItem { OrderID = 11000, ProductID = 61, Quantity = […]

龙生 11 Sep 2012

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yield（C# 参考）

yield 关键字向编译器指示它所在的方法是迭代器块。编译器生成一个类来实现迭代器块中表示的行为。在迭代器块中，yield 关键字与 return 关键字结合使用，向枚举器对象提供值。这是一个返回值，例如，在 foreach 语句的每一次循环中返回的值。 yield 关键字也可与 break 结合使用，表示迭代结束。有关迭代器的更多信息，请参见迭代器（C# 编程指南）。下面的示例演示两种形式的 yield 语句。示例：

<ol class="dp-c"><li class="alt">public class List </li><li>{ </li><li class="alt">    //using System.Collections; </li><li>    public static IEnumerable Power(int number, int exponent) </li><li class="alt">    { </li><li>        int counter = 0; </li><li class="alt">        int result = 1; </li><li>        while (counter++ < exponent) </li><li class="alt">        { </li><li>            result = result * number; </li><li class="alt">            yield return result; </li><li>        } </li><li class="alt">    } </li><li> </li><li class="alt">    static void Main() </li><li>    { </li><li class="alt">        // Display powers of 2 up to the exponent 8: </li><li>        foreach (int i in Power(2, 8)) </li><li class="alt">        { </li><li>            Console.Write("{0} ", i); </li><li class="alt">        } </li><li>    } </li><li class="alt">} </li><li>/* </li><li class="alt">Output: </li><li>2 4 8 16 32 64 128 256  </li><li class="alt">*/ </li></ol>

龙生 08 Aug 2012

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运行php出现”Error Description: 由于应用程序配置不正确”解决方法

环境: windows server 2003 、 iis6.0 、 php5.3.2 、 fcgi_1.5_x86 在winodws server 2003 上利用iis6.0搭建web服务器,采用php-cgi模式运行php脚本,提示如下错误!错误提示: FastCGI ErrorThe FastCGI Handler was unable to process the request.——————————————————————————– Error Details: Error Number: 14001 (0x800736b1).Error Description: 由于应用程序配置不正确，应用程序未能启动。重新安装应用程序可能会纠正这个问题。HTTP Error 500 – Server Error.Internet Information Services (IIS) 错误可能原因: 一.没有安装.net 2.0 的框架二.没有安装VC9运行库即VISUAL C++ 2008 解决方法:⒈安装2.0版本以上的.net Framework.net Framework下载地址:页面地址:http://www.microsoft.com/downloads/zh-cn/details.aspx?FamilyID=D0E5DEA7-AC26-4AD7-B68C-FE5076BBA986软件地址:http://download.microsoft.com/download/2/0/E/20E90413-712F-438C-988E-FDAA79A8AC3D/dotnetfx35.exe⒉安装VC9运行库即VISUAL C++ 2008，Microsoft Visual C++ 2008 Redistributable Package (x86)下载地址：页面地址:http://www.microsoft.com/downloads/details.aspx?FamilyID=9B2DA534-3E03-4391-8A4D-074B9F2BC1BF&displaylang=zh-cn软件地址:http://download.microsoft.com/download/7/5/0/7502f4e9-1f90-4895-9259-1bde67b8b9a1/vcredist_x86.exe ⒊安装完成后重新启动iis 转自：http://www.huqiang.name/2012/05/03/archives/1678.html

龙生 24 Jul 2012

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IIS6下配置fastcgi的php的教程

FastCGI的IIS模块可以让流行的应用框架在IIS上支持FastCGI协议以提供高性能和可用性的访问服务,FastCGI面向现有的网络服务器提供高性能的CGI替代标准。具体PHP 安装方法我记录下来,其中包括出现的一个错误.环境: 操作系统:Windows 2003 Server PHP版本:PHP5.25 1.下载FastCGI For IIS6 http://www.microsoft.com/downloads/details.aspx?FamilyID=2d481579-9a7c-4632-b6e6-dee9097f9dc5&displaylang=en 下载之后,双击运行进行安装. 2.下载PHP5.25 Windows版 http://www.php.net 下载.zip格式的版本,下载后解压至D:\PHP目录,并给IIS启动帐户组或用户赋予读取和运行权限. 3.注册PHP到FastCGI 在命令行下运行 cscript fcgiconfig.js -add -section:"PHP" -extension:php -path:"D:\PHP\php-cgi.exe" fcgiconfig.js 默认存放目录是:C:\WINDOWS\system32\inetsrv 4.设置将D:\PHP\php.ini-recommended重命名为为D:\PHP\php.ini 打开D:\PHP\php.ini，修改： extension_dir = "D:\PHP\ext" fastcgi.impersonate = 1 cgi.fix_pathinfo=1 cgi.force_redirect = 0 其它根据实际需要对php.ini进行设置修改然后执行： cscript fcgiconfig.js -set -section:"PHP" -InstanceMaxRequests:500 cscript fcgiconfig.js -set -section:"PHP" -EnvironmentVars:PHP_FCGI_MAX_REQUESTS:1000 以上两项设置最大池和响应连接数，可以根据运行机器的硬件配置、使用情况修改一切完毕之后重启IIS,赶紧写一个测试页试一下吧. 我第一次安装时,由于为了服务器的安全我删除了wsshell命令,导致在第3步时出现了如下错误: Microsoft JScript 运行时错误: Automation 服务器不能创建对象后通过重新注册命令:regsvr32 WSHom.ocx 问题解决重启IIS后,打开测试页出现如下提示: FastCGI Error The FastCGI Handler was unable to process the request. ——————————————————————————-- Error Details: Error Number: 5 (0x80070005). Error Description: 拒绝访问。 HTTP Error 500 – Server Error. Internet Information Services (IIS) 这个错误是由于在解压PHP之后,没有对IIS启动帐户赋予该目录的读取和运行权限.修改文件夹安全属性,问题解决. 转自：http://www.jb51.net/article/16953.htm

龙生 24 Jul 2012

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wpf 操作richtextbox

取出richTextBox里面的内容第一种方法：将richTextBox的内容以字符串的形式取出string xw = System.Windows.Markup.XamlWriter.Save(richTextBox.Document);第二种方法：将richTextBox的类容以二进制数据的方法取出FlowDocument document = richTextBox.Document;System.IO.Stream s = new System.IO.MemoryStream(); System.Windows.Markup.XamlWriter.Save(document, s); byte[] data = new byte[s.Length];s.Position = 0;s.Read(data, 0, data.Length);s.Close(); 赋值给richTextBox 第一种方法：将字符串转换为数据流赋值给richTextBox中 System.IO.StringReader sr = new System.IO.StringReader(xw);System.Xml.XmlReader xr = System.Xml.XmlReader.Create(sr);richTextBox1.Document = (FlowDocument)System.Windows.Markup.XamlReader.Load(xr);第二种方法：将二进制数据赋值给richTextBoxSystem.IO.Stream ss = new System.IO.MemoryStream(data);FlowDocument doc = System.Windows.Markup.XamlReader.Load(ss) as FlowDocument;ss.Close();richTextBox1.Document = doc; 清空RichTextBox的方法 System.Windows.Documents.FlowDocument doc = richTextBox.Document;doc.Blocks.Clear(); 如何将一个String类型的字符串赋值给richTextBoxmyRTB.Document = new FlowDocument(new Paragraph(new Run(myString))); FlowDocument doc = new FlowDocument();Paragraph p = new Paragraph(); // Paragraph 类似于 html 的 P 标签Run r = new Run(myString); // Run 是一个 Inline 的标签p.Inlines.Add(r);doc.Blocks.Add(p);myRTB.Document = […]

龙生 18 Jul 2012

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详解WPF 4 DataGrid控件的基本功能

给大家讲到WPF,我们就不得不提到WinForm，51CTO之前也报导过《WPF与WinForm对比谈多线程编程优化是关键》的技术文章，对于他们之间的优劣有了更深刻的认识。而今天我们要讲到的是WPF 4中的DataGrid空间。我们也诚挚向您推荐《让你的代码“炫”起来——WPF开发教程》。提到DataGrid 不管是网页还是应用程序开发都会频繁使用。通过它我们可以灵活的在行与列间显示各种数据。本篇将详细介绍WPF 4 中DataGrid 的相关功能。自定义列默认情况下，当我们为DataGrid 控件设置ItemSource 属性后，DataGrid 会根据数据类型自动生成相应的列，下表列出DataGrid 支持的四种列及其数据类型。在创建DataGrid 时可以通过AutoGenerateColumns 属性设置列是否自动生成，从而加入自定义列。如果DataGrid 中同时包含“自动生成列”与“用户自定义列”，则首先创建“用户自定义列”。下面代码实例中分别创建这四种列：

<ol class="dp-xml"><li class="alt"><Window x:Class="WPF4ControlTest.MainWindow" </li><li> xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" </li><li class="alt"> xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" </li><li> xmlns:local="clr-namespace:WPF4ControlTest" </li><li class="alt"> xmlns:assembly="clr-namespace:System;assembly=mscorlib" </li><li> Title="MainWindow" Height="200" Width="500"> </li><li class="alt"> <Window.Resources> </li><li> <ObjectDataProvider x:Key="sexEnum" MethodName="GetValues" </li><li class="alt"> ObjectType="{x:Type assembly:Enum}"> </li><li> <ObjectDataProvider.MethodParameters> </li><li class="alt"> <x:Type Type="local:SexOpt"/> </li><li> </ObjectDataProvider.MethodParameters> </li><li class="alt"> </ObjectDataProvider> </li><li> </Window.Resources> </li><li class="alt"> <Grid> </li><li> <DataGrid x:Name="dataGrid" ItemsSource="{Binding}" AutoGenerateColumns="False"> </li><li class="alt"> <DataGrid.Columns> </li><li> <DataGridTextColumn Header="Name" Width="80" Binding="{Binding Name}"/> </li><li class="alt"> <DataGridTextColumn Header="Age" Width="50" Binding="{Binding Age}"/> </li><li> <DataGridComboBoxColumn Width="80" Header="Sex" </li><li class="alt"> SelectedItemBinding="{Binding Sex}" </li><li> ItemsSource="{Binding Source={StaticResource sexEnum}}"/> </li><li class="alt"> <DataGridCheckBoxColumn Header="Pass Exam?" Width="100" </li><li> Binding="{Binding Pass}"/> </li><li class="alt"> <DataGridHyperlinkColumn Header="Email" Width="150" </li><li> Binding="{Binding Email}"/> </li><li class="alt"> </DataGrid.Columns> </li><li> </DataGrid> </li><li class="alt"> </Grid> </li><li></Window> </li></ol>

其中每列都包含各自的数值类型，在C# 中创建Member 类及SexOpt 枚举，并将memberData 数据绑定到DataGrid：

<ol class="dp-c"><li class="alt">using System; </li><li>using System.Windows; </li><li class="alt">using System.Collections.ObjectModel; </li><li> </li><li class="alt">namespace WPF4ControlTest </li><li>{ </li><li class="alt"> /// <summary> </li><li> /// Interaction logic for MainWindow.xaml </li><li class="alt"> /// </summary> </li><li> public partial class MainWindow : Window </li><li class="alt"> { </li><li> public MainWindow() </li><li class="alt"> { </li><li> InitializeComponent(); </li><li>ObservableCollection<Member> memberData = new ObservableCollection<Member>(); </li><li> memberData.Add(new Member() </li><li class="alt"> { </li><li> Name = "Joe", Age = "23", Sex = SexOpt.Male, </li><li class="alt"> Pass = true, Email = new Uri("mailto:Joe@school.com") </li><li> }); </li><li class="alt"> memberData.Add(new Member() </li><li> { </li><li class="alt"> Name = "Mike", Age = "20", </li><li> Sex = SexOpt.Male, Pass = false, </li><li class="alt"> Email = new Uri("mailto:Mike@school.com") </li><li> }); </li><li class="alt"> memberData.Add(new Member() </li><li> { </li><li class="alt"> Name = "Lucy", Age = "25", </li><li> Sex = SexOpt.Female, Pass = true, </li><li class="alt"> Email = new Uri("mailto:Lucy@school.com") </li><li> }); </li><li class="alt"> dataGrid.DataContext = memberData; </li><li> } </li><li class="alt"> } </li><li> </li><li class="alt"> public enum SexOpt { Male, Female }; </li><li> </li><li class="alt"> public class Member </li><li> { </li><li class="alt"> public string Name { get; set; } </li><li> public string Age { get; set; } </li><li class="alt"> public SexOpt Sex { get; set; } </li><li> public bool Pass { get; set; } </li><li class="alt"> public Uri Email { get; set; } </li><li> } </li><li class="alt">} </li></ol>

这样我们就可以通过自定义列的方式创建出DataGrid：选择模式默认情况下，DataGrid 的选择模式为“全行选择”，并且可以同时选择多行（如下图所示），我们可以通过SelectionMode 和SelectionUnit 属性来修改DataGrid 的选择模式。 SelectionUnit：包含Cell、FullRow 和CellOrRowHeader 三种单元选择模式。 ◆Cell：选择单元格； ◆FullRow：选择全行； ◆CellOrRowHeader：可选择单元格，也可以通过点击行首选择全行； SelectionMode：分为Extended 和Single 两种模式。 ◆Extended：选择多个单元（单元格或全行，由SelectionUnit 定义）； ◆Single：选择唯一单元（单元格或全行，由SelectionUnit 定义）；

<ol class="dp-xml"><li class="alt"><DataGrid x:Name="dataGrid" ItemsSource="{Binding}" AutoGenerateColumns="False" </li><li> SelectionUnit="Cell" SelectionMode="Extended">… … </li></ol>

设置SelectionUnit 和SelectionMode 后的实例效果：编辑默认情况下，我们可以直接在DataGrid 中编辑数据（下表为相关的编辑命令），当然也可以通过IsReadOnly 属性将DataGrid 设置为只读方式。

<ol class="dp-xml"><li class="alt"><DataGrid x:Name="dataGrid" ItemsSource="{Binding}" AutoGenerateColumns="False" </li><li> SelectionUnit="Cell" SelectionMode="Extended" IsReadOnly="True">… … </li></ol>

原文标题：WPF 4 DataGrid 控件（基本功能篇）链接：http://www.cnblogs.com/gnielee/archive/2010/04/16/wpf4-datagrid-control-basic.html

龙生 18 Jul 2012

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获取sqlserver数据库中所有库、表、字段名的方法

1.获取所有数据库名: SELECT Name FROM Master..SysDatabases ORDER BY Name 2.获取所有表名: SELECT Name FROM DatabaseName..SysObjects Where XType=’U' ORDER BY Name XType=’U':表示所有用户表; XType=’S':表示所有系统表; 3.获取所有字段名: SELECT Name FROM SysColumns WHERE id=Object_Id('TableName') access : 如果表存在，如何得到这个表？ SELECT * FROM MSysObjects where name=’ExamResultTime ' and type=1 and flags=0 //得到该数据库中所有的表名 SELECT name FROM MSysObjects where type=1 and flags=0 转自：http://www.soaspx.com/dotnet/sql/mssql/sql2000/sqlserver2000_20091215_2051.html

龙生 18 Jul 2012

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WPF布局-布局属性（四）

在WPF布局框架中，如果标签不设置布局属性，系统默认为填充模式。当然，我们可以通过一系列标签的属性来达到布局标签的作用。最常见的属性是Width和Height，是指定标签的宽和高。 MinWidth，MinHeight是指标签的最小宽度和最小高度，即使父容器的宽和高小于这个数字，标签也保持这个值。 MaxWidth，MaxHeight是指标签的最大宽度和最大高度。最小和最大Width，Height将将会在一个固的区间来调整标签的大小。 HorizontalAlignment是标签在当前容器中左中右的停靠。VerticalAlignment是标签在当前容器中上中下的停靠。这两种停靠都是建立在父容器内的，只有父容器内大于标签是才能看到效果。 Margin，是一个独特的属性，它的值有三种情况，单值，表示该标签距父容器四周的距，两个值，第一个值为标签距父容器左右的距离，第二个值是标签距父器上下的距离，四个值，分别距父容器左，上，右，下的距离。如果存在Width和Height属性，它们的优先级要高于Margin。但一般情况了，两种属性的设置不会同时出现，Width和Height更强调固态的值，Margin强调随性的值，但它距边缘是固定的。 Padding和Margin相似，不同的是Padding是指标签内容与标签边界的距离。 Panel.ZIndex是一个层次的属性，这个值表示标签本身在父容器上位于那一层，值越大，越位于上层。可以用Panel.SetZIndex(标签名, 3);来设置标签元素的层次。 RenderTransofrm是一个缩放的属性，就是对当前标签的直接缩放，例子如下： <Button Content="123" ;50" Height="20" Click="Button_Click" > <Button.RenderTransform> <ScaleTransform. ScaleX="0.5" ScaleY="0.5"> </ScaleTransform> </Button.RenderTransform> </Button> C#代码： button1.RenderTransform. = new ScaleTransform(2, 2); LayoutTransform是一个旋转的属性 <Button Name="button1" Content="123" ;50" Height="20" > <Button.LayoutTransform> <RotateTransform. Angle="45"></RotateTransform> </Button.LayoutTransform> </Button> C#代码： button1.LayoutTransform. = new RotateTransform(90); 转换的类型还有MatrixTransform，如 <Button Name="button1" Content="123" ;50" Height="20" > <Button.LayoutTransform> <MatrixTransform. Matrix="3, 1, 1, 3, 0, 0"></MatrixTransform> </Button.LayoutTransform> </Button> C#代码： button1.LayoutTransform. = new MatrixTransform(3, 1, 1, 3, 0, 0); 上面的转换是用矩阵的方式实现，下面从x和y轴上来建立转换： <Button.LayoutTransform> <SkewTransform. AngleX="30" AngleY="30" ></SkewTransform> </Button.LayoutTransform> C#代码： button1.LayoutTransform. = new SkewTransform(10, 30, […]

龙生 18 Jul 2012

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Asp.net Web Applicatoin实现自定义HttpModule拦截异常处理

Asp.net的NamePipe机制给我们提供了很多扩展性. 使用HttpModule我们可能实现的有: 强制站点范围的Cookie策略集中化监控与日志编写设置与删除HTTP头控制response输出,如删除多余空白字符 Session管理认证与受权下面我们来看如何实现自定义异常处理:

1	<span class="lnum"> 1: </span> <span class="kwrd">public</span> <span class="kwrd">class</span> ErrorModule:IHttpModule

1	<span class="lnum"> 2: </span> {

1	<span class="lnum"> 3: </span> <span class="preproc">#region</span> IHttpModule Members

1	<span class="lnum"> 4: </span>

1	<span class="lnum"> 5: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 6: </span> <span class="rem">/// Disposes of the resources (other than memory) used by the module that implements <see cref="T:System.Web.IHttpModule"/>.</span>

1	<span class="lnum"> 7: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 8: </span> <span class="kwrd">public</span> <span class="kwrd">void</span> Dispose()

1	<span class="lnum"> 9: </span> {

1	<span class="lnum"> 10: </span> <span class="rem">//do nothing </span>

1	<span class="lnum"> 11: </span> }

1	<span class="lnum"> 12: </span>

1	<span class="lnum"> 13: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 14: </span> <span class="rem">/// Initializes a module and prepares it to handle requests.</span>

1	<span class="lnum"> 15: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 16: </span> <span class="rem">/// <param name="context">An <see cref="T:System.Web.HttpApplication"/> that provides access to the methods, properties, and events common to all application objects within an ASP.NET application</param></span>

1	<span class="lnum"> 17: </span> <span class="kwrd">public</span> <span class="kwrd">void</span> Init(HttpApplication context)

1	<span class="lnum"> 18: </span> {

1	<span class="lnum"> 19: </span> context.Error += <span class="kwrd">new</span> EventHandler(customcontext_Error);

1	<span class="lnum"> 20: </span> }

1	<span class="lnum"> 21: </span>

1	<span class="lnum"> 22: </span> <span class="kwrd">private</span> <span class="kwrd">void</span> customcontext_Error(<span class="kwrd">object</span> sender, EventArgs e)

1	<span class="lnum"> 23: </span> {

1	<span class="lnum"> 24: </span> HttpContext ctx = HttpContext.Current;

1	<span class="lnum"> 25: </span> HttpResponse response = ctx.Response;

1	<span class="lnum"> 26: </span> HttpRequest request = ctx.Request;

1	<span class="lnum"> 27: </span>

1	<span class="lnum"> 28: </span> Exception exception = ctx.Server.GetLastError();

1	<span class="lnum"> 29: </span>

1	<span class="lnum"> 30: </span> var sboutput = <span class="kwrd">new</span> StringBuilder();

1	<span class="lnum"> 31: </span> sboutput.Append(<span class="str">"Querystring:<p/>"</span>);

1	<span class="lnum"> 32: </span> <span class="rem">//Get out the query string </span>

1	<span class="lnum"> 33: </span> <span class="kwrd">int</span> count = request.QueryString.Count;

1	<span class="lnum"> 34: </span> <span class="kwrd">for</span> (<span class="kwrd">int</span> i = 0; i < count; i++)

1	<span class="lnum"> 35: </span> {

1	<span class="lnum"> 36: </span> sboutput.AppendFormat(<span class="str">"<br/> {0}:-- {1} "</span>, request.QueryString.Keys[i], request.QueryString[i]);

1	<span class="lnum"> 37: </span> }

1	<span class="lnum"> 38: </span> <span class="rem">//Get out the form collection info</span>

1	<span class="lnum"> 39: </span> sboutput.Append(<span class="str">"<p>-------------------------<p/>Form:<p/>"</span>);

1	<span class="lnum"> 40: </span> count = request.Form.Count;

1	<span class="lnum"> 41: </span> <span class="kwrd">for</span> (<span class="kwrd">int</span> i = 0; i < count; i++)

1	<span class="lnum"> 42: </span> {

1	<span class="lnum"> 43: </span> sboutput.AppendFormat(<span class="str">"<br/> {0}:-- {1} -- <br/>"</span>, request.Form.Keys[i], request.Form[i]);

1	<span class="lnum"> 44: </span> }

1	<span class="lnum"> 45: </span> sboutput.Append(<span class="str">"<p>-------------------------<p/>ErrorInfo:<p/>"</span>);

1	<span class="lnum"> 46: </span> sboutput.AppendFormat(<span class="str">@"Your request could not processed. Please press the back button on your browser and try again.<br/></span>

1	<span class="lnum"> 47: </span> If the problem persists, please contact technical support<p/>

1	<span class="lnum"> 48: </span> Information below is for technical support:<p/>

1	<span class="lnum"> 49: </span> <p/>URL:{0}<p/>Stacktrace:---<br/>{1}<p/>InnerException:<br/>{2}"

1	<span class="lnum"> 50: </span> , ctx.Request.Url, exception.InnerException.StackTrace, exception.InnerException);

1	<span class="lnum"> 51: </span>

1	<span class="lnum"> 52: </span> response.Write(sboutput.ToString());

1	<span class="lnum"> 53: </span>

1	<span class="lnum"> 54: </span> <span class="rem">// To let the page finish running we clear the error</span>

1	<span class="lnum"> 55: </span> ctx.Server.ClearError();

1	<span class="lnum"> 56: </span> }

1	<span class="lnum"> 57: </span>

1	<span class="lnum"> 58: </span> <span class="preproc">#endregion</span>

1	<span class="lnum"> 59: </span>

1	<span class="lnum"> 60: </span> }

上面的代码实现了IHttpModule接口, 实现基于HttpApplication.Error事件, 接着我们自定义输出了一些信息,包括Form,QueryString. 最后把原来的Error信息清除了,这样你看到以前那个黄页了. 这个自定义的Module可以用于调试Web应用程序使用. Web.config中配置:

1	<span class="kwrd"><</span><span class="html">httpModules</span><span class="kwrd">></span>

1	<span class="kwrd"><</span><span class="html">add</span> <span class="attr">name</span><span class="kwrd">="ErrorLoggingModule"</span> <span class="attr">type</span><span class="kwrd">="MyWeb.ErrorModule"</span><span class="kwrd">/></span>

1	<span class="kwrd"></</span><span class="html">httpModules</span><span class="kwrd">></span>

实际开发中,我们可以做的事儿很多,对这些信息记日志,发邮件. 如下, 我们演示使用Enterprise Library 做异常处理并日志记录,部分代码如下:

1	<span class="lnum"> 1: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 2: </span> <span class="rem">/// Handles the Error event of the EntLibLogging control.</span>

1	<span class="lnum"> 3: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 4: </span> <span class="rem">/// <param name="sender">The source of the event.</param></span>

1	<span class="lnum"> 5: </span> <span class="rem">/// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param></span>

1	<span class="lnum"> 6: </span> <span class="rem">/// <remarks>author Petter Liu http://wintersun.cnblogs.com</remarks></span>

1	<span class="lnum"> 7: </span> <span class="kwrd">private</span> <span class="kwrd">void</span> EntLibLogging_Error(<span class="kwrd">object</span> sender, EventArgs e)

1	<span class="lnum"> 8: </span> {

1	<span class="lnum"> 9: </span> var builder = <span class="kwrd">new</span> ConfigurationSourceBuilder();

1	<span class="lnum"> 10: </span>

1	<span class="lnum"> 11: </span> builder.ConfigureInstrumentation()

1	<span class="lnum"> 12: </span> .ForApplicationInstance(<span class="str">"MyApp"</span>)

1	<span class="lnum"> 13: </span> .EnableLogging()

1	<span class="lnum"> 14: </span> .EnablePerformanceCounters();

1	<span class="lnum"> 15: </span>

1	<span class="lnum"> 16: </span> <span class="rem">//a single exception handling policy named MyPolicy for exceptions of type ArgumentNullException. </span>

1	<span class="lnum"> 17: </span> <span class="rem">//The handler for this exception policy will log the exception to the General category (defined in the Logging Application Block configuration) </span>

1	<span class="lnum"> 18: </span> <span class="rem">//as a warning with event ID 9000, wrap the ArgumentNullException with an InvalidOperationException, set the new exception message to MyMessage, and then re-throw the exception.</span>

1	<span class="lnum"> 19: </span> builder.ConfigureExceptionHandling()

1	<span class="lnum"> 20: </span> .GivenPolicyWithName(<span class="str">"MyPolicy"</span>)

1	<span class="lnum"> 21: </span> .ForExceptionType<ArgumentNullException>()

1	<span class="lnum"> 22: </span> .LogToCategory(<span class="str">"Exception"</span>)

1	<span class="lnum"> 23: </span> .WithSeverity(System.Diagnostics.TraceEventType.Warning)

1	<span class="lnum"> 24: </span> .UsingEventId(9000)

1	<span class="lnum"> 25: </span> .WrapWith<InvalidOperationException>()

1	<span class="lnum"> 26: </span> .UsingMessage(<span class="str">"MyMessage"</span>)

1	<span class="lnum"> 27: </span> .ThenNotifyRethrow();

1	<span class="lnum"> 28: </span>

1	<span class="lnum"> 29: </span> <span class="rem">//logging application </span>

1	<span class="lnum"> 30: </span> builder.ConfigureLogging()

1	<span class="lnum"> 31: </span> .WithOptions

1	<span class="lnum"> 32: </span> .DoNotRevertImpersonation()

1	<span class="lnum"> 33: </span> .LogToCategoryNamed(<span class="str">"Exception"</span>)

1	<span class="lnum"> 34: </span> .SendTo.FlatFile(<span class="str">"Exception Logging File"</span>)

1	<span class="lnum"> 35: </span> .FormatWith(<span class="kwrd">new</span> FormatterBuilder()

1	<span class="lnum"> 36: </span> .TextFormatterNamed(<span class="str">"Text Formatter"</span>)

1	<span class="lnum"> 37: </span> . UsingTemplate(<span class="str">"Timestamp: {timestamp}{newline}Message: {message}{newline}Category: {category}{newline}"</span>))

1	<span class="lnum"> 38: </span> .ToFile(<span class="str">"d:\\logs\\ExceptionsLog.log"</span>)

1	<span class="lnum"> 39: </span> .SendTo.RollingFile(<span class="str">"Rolling Log files"</span>)

1	<span class="lnum"> 40: </span> .RollAfterSize(1024)

1	<span class="lnum"> 41: </span> .ToFile(<span class="str">"d:\\logs\\Rollinglog.log"</span>)

1	<span class="lnum"> 42: </span> .LogToCategoryNamed(<span class="str">"General"</span>)

1	<span class="lnum"> 43: </span> .WithOptions.SetAsDefaultCategory()

1	<span class="lnum"> 44: </span> .SendTo.SharedListenerNamed(<span class="str">"Exception Logging File"</span>);

1	<span class="lnum"> 45: </span>

1	<span class="lnum"> 46: </span> var configSource = <span class="kwrd">new</span> DictionaryConfigurationSource();

1	<span class="lnum"> 47: </span> builder.UpdateConfigurationWithReplace(configSource);

1	<span class="lnum"> 48: </span> EnterpriseLibraryContainer.Current = EnterpriseLibraryContainer.CreateDefaultContainer(configSource);

1	<span class="lnum"> 49: </span>

1	<span class="lnum"> 50: </span> var ex = HttpContext.Current.Server.GetLastError();

1	<span class="lnum"> 51: </span> var em = EnterpriseLibraryContainer.Current.GetInstance<ExceptionManager>();

1	<span class="lnum"> 52: </span> em.HandleException(ex.InnerException, <span class="str">"MyPolicy"</span>);

1	<span class="lnum"> 53: </span> }

注意上面的代码, 为了运行代码您需要引用以下程序集 Enterprise Library Share Common LibraryMicrosoft.Practices.ServiceLocationLogging Application BlockException Handling Application BlockException Handling Logging Provider 这里我们使用Fluent API配置, 因此没有配置XML文件. 所以不需要Web.Config中配置任何信息. 代码中有注释. 为了测试我们使用一个PAGE故意Throw 一个ArgumentNullException. 通过Server.GetLastError()获取Exception, 这时由名为MyPolicy策略处理异常. 对于ArgumentNullException把它们记录日志到名为Exception分类中,这个日志文件位于d:\\logs\\ExceptionLog.log.实际开发你完全按照你的需要来自定义策略. 然后这个日志文件中写出的内容是这样的:

----------------------------------------Timestamp: 2011-11-12 5:57:08Message: HandlingInstanceID: a99d005d-5f8d-4613-9522-2d60efb089aaAn exception of type 'System.ArgumentNullException' occurred and was caught.----------------------------------------------------------------------------11/12/2011 13:57:08Type : System.ArgumentNullException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089Message : Value cannot be null.Parameter name: Demo errorSource : MyWebHelp link : ParamName : Demo errorData : System.Collections.ListDictionaryInternalTargetSite : Void Page_Load(System.Object, System.EventArgs)Stack Trace : at MyWeb.About.Page_Load(Object sender, EventArgs e) in H:\My Project\DotNet40\TDD2010\WebHost\MyWeb\About.aspx.cs:line 14 at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) at System.Web.UI.Control.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)Additional Info:MachineName : USERTimeStamp : 2011-11-12 5:57:08FullName : Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35AppDomainName : 3e5cb21e-3-129655510216406250ThreadIdentity : WindowsIdentity : USER\PetterCategory: Exception

由于我们日志模块我们配置还需要写Rollinglog.log文件,内容如下:

----------------------------------------Exception Warning: 9000 : Timestamp: 2011-11-12 5:57:08Message: HandlingInstanceID: a99d005d-5f8d-4613-9522-2d60efb089aaAn exception of type 'System.ArgumentNullException' occurred and was caught.----------------------------------------------------------------------------11/12/2011 13:57:08Type : System.ArgumentNullException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089Message : Value cannot be null.Parameter name: Demo errorSource : MyWebHelp link : ParamName : Demo errorData : System.Collections.ListDictionaryInternalTargetSite : Void Page_Load(System.Object, System.EventArgs)Stack Trace : at MyWeb.About.Page_Load(Object sender, EventArgs e) in H:\My Project\DotNet40\TDD2010\WebHost\MyWeb\About.aspx.cs:line 14 at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) at System.Web.UI.Control.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)Additional Info:MachineName : USERTimeStamp : 2011-11-12 5:57:08FullName : Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35AppDomainName : 3e5cb21e-3-129655510216406250ThreadIdentity : WindowsIdentity : USER\PetterCategory: ExceptionPriority: 0EventId: 9000Severity: WarningTitle:Enterprise Library Exception HandlingMachine: USERApp Domain: 3e5cb21e-3-129655510216406250ProcessId: 2444Process Name: C:\Program Files\Common Files\Microsoft Shared\DevServer\10.0\WebDev.WebServer40.exeThread Name: Win32 ThreadId:2748Extended Properties: ----------------------------------------

1	你可以看到上面的EventId=9000与我们之前在CODE中配置是相同的. <br />

1	在开源社区有一个组件<a href="http://code.google.com/p/elmah/" target="_blank">ELMAH</a>(Error Logging Modules and Handlers for ASP.NET),已实现Error处理发邮件,写DB,发送到SNS等功能. 我们随意来看下它的代码:<br />它就是基于IHttpModule的扩展,下面代码来ELMAH:

1	<span class="lnum"> 1: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 2: </span> <span class="rem">/// Provides an abstract base class for <see cref="IHttpModule"/> that</span>

1	<span class="lnum"> 3: </span> <span class="rem">/// supports discovery from within partial trust environments.</span>

1	<span class="lnum"> 4: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 5: </span> <span class="kwrd">public</span> <span class="kwrd">abstract</span> <span class="kwrd">class</span> HttpModuleBase : IHttpModule

1	<span class="lnum"> 6: </span> {

1	<span class="lnum"> 7: </span> <span class="kwrd">void</span> IHttpModule.Init(HttpApplication context)

1	<span class="lnum"> 8: </span> {

1	<span class="lnum"> 9: </span> <span class="kwrd">if</span> (context == <span class="kwrd">null</span>)

1	<span class="lnum"> 10: </span> <span class="kwrd">throw</span> <span class="kwrd">new</span> ArgumentNullException(<span class="str">"context"</span>);

1	<span class="lnum"> 11: </span>

1	<span class="lnum"> 12: </span> <span class="kwrd">if</span> (SupportDiscoverability)

1	<span class="lnum"> 13: </span> HttpModuleRegistry.RegisterInPartialTrust(context, <span class="kwrd">this</span>);

1	<span class="lnum"> 14: </span>

1	<span class="lnum"> 15: </span> OnInit(context);

1	<span class="lnum"> 16: </span> }

1	<span class="lnum"> 17: </span>

1	<span class="lnum"> 18: </span> <span class="kwrd">void</span> IHttpModule.Dispose()

1	<span class="lnum"> 19: </span> {

1	<span class="lnum"> 20: </span> OnDispose();

1	<span class="lnum"> 21: </span> }

1	<span class="lnum"> 22: </span>

1	<span class="lnum"> 23: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 24: </span> <span class="rem">/// Determines whether the module will be registered for discovery</span>

1	<span class="lnum"> 25: </span> <span class="rem">/// in partial trust environments or not.</span>

1	<span class="lnum"> 26: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 27: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> <span class="kwrd">bool</span> SupportDiscoverability

1	<span class="lnum"> 28: </span> {

1	<span class="lnum"> 29: </span> get { <span class="kwrd">return</span> <span class="kwrd">false</span>; }

1	<span class="lnum"> 30: </span> }

1	<span class="lnum"> 31: </span>

1	<span class="lnum"> 32: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 33: </span> <span class="rem">/// Initializes the module and prepares it to handle requests.</span>

1	<span class="lnum"> 34: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 35: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> <span class="kwrd">void</span> OnInit(HttpApplication application) {}

1	<span class="lnum"> 36: </span>

1	<span class="lnum"> 37: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 38: </span> <span class="rem">/// Disposes of the resources (other than memory) used by the module.</span>

1	<span class="lnum"> 39: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 40: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> <span class="kwrd">void</span> OnDispose() {}

1	<span class="lnum"> 41: </span> }

1	这是ErrorLogModule实现之前HttpModuleBase:

1	<span class="lnum"> 1: </span><span class="kwrd">public</span> <span class="kwrd">class</span> ErrorLogModule : HttpModuleBase, IExceptionFiltering

1	<span class="lnum"> 2: </span> {

1	<span class="lnum"> 3: </span> <span class="kwrd">public</span> <span class="kwrd">event</span> ExceptionFilterEventHandler Filtering;

1	<span class="lnum"> 4: </span> <span class="kwrd">public</span> <span class="kwrd">event</span> ErrorLoggedEventHandler Logged;

1	<span class="lnum"> 5: </span>

1	<span class="lnum"> 6: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 7: </span> <span class="rem">/// Initializes the module and prepares it to handle requests.</span>

1	<span class="lnum"> 8: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 9: </span>

1	<span class="lnum"> 10: </span> <span class="kwrd">protected</span> <span class="kwrd">override</span> <span class="kwrd">void</span> OnInit(HttpApplication application)

1	<span class="lnum"> 11: </span> {

1	<span class="lnum"> 12: </span> <span class="kwrd">if</span> (application == <span class="kwrd">null</span>)

1	<span class="lnum"> 13: </span> <span class="kwrd">throw</span> <span class="kwrd">new</span> ArgumentNullException(<span class="str">"application"</span>);

1	<span class="lnum"> 14: </span>

1	<span class="lnum"> 15: </span> application.Error += <span class="kwrd">new</span> EventHandler(OnError);

1	<span class="lnum"> 16: </span> ErrorSignal.Get(application).Raised += <span class="kwrd">new</span> ErrorSignalEventHandler(OnErrorSignaled);

1	<span class="lnum"> 17: </span> }

1	<span class="lnum"> 18: </span>

1	<span class="lnum"> 19: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 20: </span> <span class="rem">/// Gets the <see cref="ErrorLog"/> instance to which the module</span>

1	<span class="lnum"> 21: </span> <span class="rem">/// will log exceptions.</span>

1	<span class="lnum"> 22: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 23: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> ErrorLog GetErrorLog(HttpContext context)

1	<span class="lnum"> 24: </span> {

1	<span class="lnum"> 25: </span> <span class="kwrd">return</span> ErrorLog.GetDefault(context);

1	<span class="lnum"> 26: </span> }

1	<span class="lnum"> 27: </span>

1	<span class="lnum"> 28: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 29: </span> <span class="rem">/// The handler called when an unhandled exception bubbles up to </span>

1	<span class="lnum"> 30: </span> <span class="rem">/// the module.</span>

1	<span class="lnum"> 31: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 32: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> <span class="kwrd">void</span> OnError(<span class="kwrd">object</span> sender, EventArgs args)

1	<span class="lnum"> 33: </span> {

1	<span class="lnum"> 34: </span> HttpApplication application = (HttpApplication) sender;

1	<span class="lnum"> 35: </span> LogException(application.Server.GetLastError(), application.Context);

1	<span class="lnum"> 36: </span> }

1	<span class="lnum"> 37: </span>

1	<span class="lnum"> 38: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 39: </span> <span class="rem">/// The handler called when an exception is explicitly signaled.</span>

1	<span class="lnum"> 40: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 41: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> <span class="kwrd">void</span> OnErrorSignaled(<span class="kwrd">object</span> sender, ErrorSignalEventArgs args)

1	<span class="lnum"> 42: </span> {

1	<span class="lnum"> 43: </span> LogException(args.Exception, args.Context);

1	<span class="lnum"> 44: </span> }

1	<span class="lnum"> 45: </span>

1	<span class="lnum"> 46: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 47: </span> <span class="rem">/// Logs an exception and its context to the error log.</span>

1	<span class="lnum"> 48: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 49: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> <span class="kwrd">void</span> LogException(Exception e, HttpContext context)

1	<span class="lnum"> 50: </span> {

1	<span class="lnum"> 51: </span> <span class="kwrd">if</span> (e == <span class="kwrd">null</span>)

1	<span class="lnum"> 52: </span> <span class="kwrd">throw</span> <span class="kwrd">new</span> ArgumentNullException(<span class="str">"e"</span>);

1	<span class="lnum"> 53: </span>

1	<span class="lnum"> 54: </span> <span class="rem">//</span>

1	<span class="lnum"> 55: </span> <span class="rem">// Fire an event to check if listeners want to filter out</span>

1	<span class="lnum"> 56: </span> <span class="rem">// logging of the uncaught exception.</span>

1	<span class="lnum"> 57: </span> <span class="rem">//</span>

1	<span class="lnum"> 58: </span>

1	<span class="lnum"> 59: </span> ExceptionFilterEventArgs args = <span class="kwrd">new</span> ExceptionFilterEventArgs(e, context);

1	<span class="lnum"> 60: </span> OnFiltering(args);

1	<span class="lnum"> 61: </span>

1	<span class="lnum"> 62: </span> <span class="kwrd">if</span> (args.Dismissed)

1	<span class="lnum"> 63: </span> <span class="kwrd">return</span>;

1	<span class="lnum"> 64: </span>

1	<span class="lnum"> 65: </span> <span class="rem">//</span>

1	<span class="lnum"> 66: </span> <span class="rem">// Log away...</span>

1	<span class="lnum"> 67: </span> <span class="rem">//</span>

1	<span class="lnum"> 68: </span>

1	<span class="lnum"> 69: </span> ErrorLogEntry entry = <span class="kwrd">null</span>;

1	<span class="lnum"> 70: </span>

1	<span class="lnum"> 71: </span> <span class="kwrd">try</span>

1	<span class="lnum"> 72: </span> {

1	<span class="lnum"> 73: </span> Error error = <span class="kwrd">new</span> Error(e, context);

1	<span class="lnum"> 74: </span> ErrorLog log = GetErrorLog(context);

1	<span class="lnum"> 75: </span> <span class="kwrd">string</span> id = log.Log(error);

1	<span class="lnum"> 76: </span> entry = <span class="kwrd">new</span> ErrorLogEntry(log, id, error);

1	<span class="lnum"> 77: </span> }

1	<span class="lnum"> 78: </span> <span class="kwrd">catch</span> (Exception localException)

1	<span class="lnum"> 79: </span> {

1	<span class="lnum"> 80: </span> <span class="rem">//</span>

1	<span class="lnum"> 81: </span> <span class="rem">// IMPORTANT! We swallow any exception raised during the </span>

1	<span class="lnum"> 82: </span> <span class="rem">// logging and send them out to the trace . The idea </span>

1	<span class="lnum"> 83: </span> <span class="rem">// here is that logging of exceptions by itself should not </span>

1	<span class="lnum"> 84: </span> <span class="rem">// be critical to the overall operation of the application.</span>

1	<span class="lnum"> 85: </span> <span class="rem">// The bad thing is that we catch ANY kind of exception, </span>

1	<span class="lnum"> 86: </span> <span class="rem">// even system ones and potentially let them slip by.</span>

1	<span class="lnum"> 87: </span> <span class="rem">//</span>

1	<span class="lnum"> 88: </span>

1	<span class="lnum"> 89: </span> Trace.WriteLine(localException);

1	<span class="lnum"> 90: </span> }

1	<span class="lnum"> 91: </span>

1	<span class="lnum"> 92: </span> <span class="kwrd">if</span> (entry != <span class="kwrd">null</span>)

1	<span class="lnum"> 93: </span> OnLogged(<span class="kwrd">new</span> ErrorLoggedEventArgs(entry));

1	<span class="lnum"> 94: </span> }

1	<span class="lnum"> 95: </span>

1	<span class="lnum"> 96: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 97: </span> <span class="rem">/// Raises the <see cref="Logged"/> event.</span>

1	<span class="lnum"> 98: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 99: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> <span class="kwrd">void</span> OnLogged(ErrorLoggedEventArgs args)

1	<span class="lnum"> 100: </span> {

1	<span class="lnum"> 101: </span> ErrorLoggedEventHandler handler = Logged;

1	<span class="lnum"> 102: </span>

1	<span class="lnum"> 103: </span> <span class="kwrd">if</span> (handler != <span class="kwrd">null</span>)

1	<span class="lnum"> 104: </span> handler(<span class="kwrd">this</span>, args);

1	<span class="lnum"> 105: </span> }

1	<span class="lnum"> 106: </span>

1	<span class="lnum"> 107: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 108: </span> <span class="rem">/// Raises the <see cref="Filtering"/> event.</span>

1	<span class="lnum"> 109: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 110: </span> <span class="kwrd">protected</span> <span class="kwrd">virtual</span> <span class="kwrd">void</span> OnFiltering(ExceptionFilterEventArgs args)

1	<span class="lnum"> 111: </span> {

1	<span class="lnum"> 112: </span> ExceptionFilterEventHandler handler = Filtering;

1	<span class="lnum"> 113: </span>

1	<span class="lnum"> 114: </span> <span class="kwrd">if</span> (handler != <span class="kwrd">null</span>)

1	<span class="lnum"> 115: </span> handler(<span class="kwrd">this</span>, args);

1	<span class="lnum"> 116: </span> }

1	<span class="lnum"> 117: </span>

1	<span class="lnum"> 118: </span> <span class="rem">/// <summary></span>

1	<span class="lnum"> 119: </span> <span class="rem">/// Determines whether the module will be registered for discovery</span>

1	<span class="lnum"> 120: </span> <span class="rem">/// in partial trust environments or not.</span>

1	<span class="lnum"> 121: </span> <span class="rem">/// </summary></span>

1	<span class="lnum"> 122: </span> <span class="kwrd">protected</span> <span class="kwrd">override</span> <span class="kwrd">bool</span> SupportDiscoverability

1	<span class="lnum"> 123: </span> {

1	<span class="lnum"> 124: </span> get { <span class="kwrd">return</span> <span class="kwrd">true</span>; }

1	<span class="lnum"> 125: </span> }

1	<span class="lnum"> 126: </span> }

1	更多的功能等待您去挖掘,我们在实际开发中按需选择.希望这篇POST对您开发有帮助.<br />

转自：http://www.cnblogs.com/wintersun/archive/2011/11/12/2246513.html

龙生 13 Jul 2012

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