让ASP.NET的FileUpload控件支持浏览自动上传功能(转载)
FileUpload控件默认不支持服务端的ONCHANGE事件,此时用一种变通的方法借用客户端的onchange事件,调用__doPostBack方法来用LinkButton的OnClick事件模拟一个事件触发的过程,具体代码如下:
客户端:
1 <asp:FileUpload ID="fuPhoto" onchange="javascript:__doPostBack('lbUploadPhoto','')" runat="server" ToolTip="选择图片" />
2 <asp:LinkButton ID="lbUploadPhoto" runat="server" OnClick="lbUploadPhoto_Click"></asp:LinkButton>
后台代码:
1.//自动上传事件 2. protected void lbUploadPhoto_Click(object sender, EventArgs e) 3. { 4. fileUpload(); 5. } 6. //从控件上传文件 7. public void fileUpload() 8. { 9. if (fuPhoto.PostedFile != null && fuPhoto.PostedFile.ContentLength > 0) 10. { 11. string ext = System.IO.Path.GetExtension(fuPhoto.PostedFile.FileName).ToLower(); 12. if (ext != ".jpg" && ext != ".jepg" && ext != ".bmp" && ext != ".gif") 13. { 14. return; 15. } 16. string filename = "Image_" + DateTime.Now.ToString("yyyyMMddHHmmss") + ext; 17. string path = "./UploadPhoto/" + filename; 18. fuPhoto.PostedFile.SaveAs(Server.MapPath(path)); 19. Response.Redirect("ImageCut.aspx?Picurl=" + Server.UrlEncode(path)); 20. } 21. else 22. { 23. //do some thing; 24. } 25. }