Asp.Net中强制文件下载

public HttpResponseMessage ImportTemplate(string fileName)

{

var context = HttpContext.Current;

var response = new HttpResponseMessage(HttpStatusCode.OK);

var path = context.Server.MapPath("~/App_Data/" + fileName);

if (string.IsNullOrEmpty(fileName) || !File.Exists(path))

{

response = new HttpResponseMessage(HttpStatusCode.NotFound)

{

Content = new StringContent($"<meta charset=\"utf-8\"><h3>【{fileName}】不存在。</h3>", Encoding.UTF8)

};

response.Content.Headers.ContentType = new MediaTypeHeaderValue("text/html");

return response;

}

var stream = new FileStream(path, FileMode.Open, FileAccess.Read);

response.Content = new StreamContent(stream);

response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");

response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")

{

FileName = HttpUtility.UrlEncode(fileName)

};

response.Headers.Add("Access-Control-Expose-Headers", "FileName");

response.Headers.Add("FileName", HttpUtility.UrlEncode(fileName));

return response;

}