ASP.NET中通过对话框方式下载文件

ASP.NET中通过对话框方式下载文件

1 通过探出对话框提示文件下载或打开

2 通过自定义Header让特定的应用程序打开文件

使用的方法：Response.TransmitFile() http://www.it55.com/

例程： IT资讯之家 www.it55.com

Response.ContentType = “image/jpeg”;
Response.AppendHeader(“Content-Disposition”,”attachment; filename=SailBig.jpg”);
Response.TransmitFile( Server.MapPath(“~/images/sailbig.jpg”) );

45398 www.it55.com it55学习IT知识，享受IT生活 4dfkjn

流传送所使用的方法： vd;k;l www.it55.com rdfg

Response.BinaryWrite()和Response.OutputStream() 45398 www.it55.com it55学习IT知识，享受IT生活 4dfkjn

例程：

Bitmap bmp = wwWebUtils.CornerImage(backcolor, color, c, Radius, Height, Width);
Response.ContentType = “image/jpeg”;
Response.AppendHeader(“Content-Disposition”,”attenment; filename=LeftCorner.jpg”);
bmp.Save(Response.OutputStream, ImageFormat.Jpeg);

关于Content Type(MIME Type)的参考URL：

http://www.w3.org/TR/html4/types.html (概述) IT资讯之家 www.it55.com

http://www.iana.org/assignments/media-types/ (详细列表) 免费资源www.it55.com

常见问题解决方案：

http://www.it55.com/

1、当从资源文件或者数据库BLOB字段载入图像出现错误 http://www.it55.com/

错误内容：A generic error occurred in GDI+ http://www.it55.com/

代码：

sflj www.it55.com kg^&fgd

Bitmap bmp = this.GetGlobalResourceObject(“Resource”,”_BitMap”) as Bitmap;
Response.ContentType=”image/jpeg”;
bmp.Save(Response.OutputStream, ImageFormat.Jpeg);
Response.End();

解决方法，再创建一个实例接收从资源文件或者数据库BLOB字段读入的图像内容。 www.it55.com在线教程

解决方案代码：

免费资源www.it55.com

Bitmap bmp = this.GetGlobalResourceObject(“Resource”, ”_BitMap”) as Bitmap;
Bitmap temp = new Bitmap(bmp);
Response.ContentType = “image/jpeg”;
Temp.Save(Response.OutputStream, ImageFormat.Jpeg);
bmp.Dispose();
temp.Dispose();
Response.End();

2、无法直接把PNG图像存入到输出流

原因：PNG是特殊的图片格式

it55.com

解决方案代码： 45398 www.it55.com it55学习IT知识，享受IT生活 4dfkjn

Bitmap bmp = this.GetGlobalResourceObject( “Resource”, “_BitMap”) as Bitmap;
Bitmap temp = new Bitmap(bmp);
MemoryStream ms = new MemoryStream();
Response.ContentType=”image/png”;
temp.Save(ms, System.Drawing.Imaging, ImageFormat.Png);
Ms.WriteTo(Response.OutputStream);
bmp.Dispose();
temp.Dispose();
Response.End(); it55.com

3、解决缓存问题

Response.ContentType=”image/png”;
Response.Buffer = false;
Response.Clear();
MemoryStream stream1 = new MemoryStream();
// DrawPie method return an Image
This.DrawPie(table1).Save(stream1,ImageFormat.Png);
Response.BinaryWrite(stream1.ToArray());
Base.OnPreInit(e); www.it55.com

（编辑：IT资讯之家 www.it55.com）