如何从数据库下载文件 [英] How to download the file from the database

问题描述

亲爱的所有人

这是我在页面中用来从数据库下载文件的代码.我已经以varbinary格式存储了.当我单击linkbutton时，文件必须打开.但是我遇到了javscript错误.请帮助我解决这个问题.

Dear All

This is the code I have used in my page to download the file from the database. I have stored in the varbinary format. When i clicked the linkbutton , the file has to open.but I''m getting the javscript error. Please help me to sort out this.

byte[] fileData =(byte[])ds.Tables[0].Rows[0][3];
            Response.ClearContent();
            Response.AddHeader("Content-Disposition", "attachment; filename=1.xls"); // + ds.Tables[0].Rows[0][2]);
            System.IO.BinaryWriter bw = new System.IO.BinaryWriter(Response.OutputStream);
            bw.Write(fileData);
            bw.Close();
            Response.ContentType =ds.Tables[0].Rows[0][4].ToString()  ;
            Response.End();

问题在于fileupload控件保留在ajax updatepanel控件内.现在，当我将控件放置在面板之外时，它就可以工作了.但是我需要知道是什么原因.

问候
Sheik

The problem is that fileupload control kept inside the ajax updatepanel control. Now its working when I placed the control outside of the panel. But I need to know what''s the reason.

Regards
Sheik

推荐答案

什么是JavaScript错误?

这是我过去所做的事情，没有错误:

What javascript error?

This is how I have done it in the past, with no errors:

byte[] fileData =(byte[])ds.Tables[0].Rows[0][3];
HttpContext context = HttpContext.Current;
context.Response.Clear();
context.Response.ClearContent();
context.Response.ClearHeaders();
context.Response.Buffer = true;
context.Response.ContentType = ds.Tables[0].Rows[0][4].ToString()  ;
context.Response.AppendHeader("Content-Disposition", "attachment; filename=1.xls");
context.Response.AppendHeader("content-length", filedata.Length.ToString());
context.Response.BinaryWrite(filedata);
context.Response.Flush();
context.Response.End();

(现在来看，我认为Clear清除后，ClearContent和ClearHeaders可能是多余的.:-p)

(Looking at it now, I think the ClearContent and ClearHeaders might be redundant after the Clear. :-p )

您没有在问题中提供完整的细节.之前在问答"部分已经回答了类似的问题，请进行检查.

从数据库中保存和检索文件 [

You didn''t provide complete details in your question. Already answered a similar question here before in Q/A section, check it.

Save and Retrieve Files from Database[^]

string style = @"<style> .text { mso-number-format:\@; } </style> ";
GridView1.Visible = true;
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition",
"attachment;filename=file.xls");
Response.Charset = "";
Response.ContentType = "application/vnd.ms-excel";
StringWriter sw = new StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(sw);
//GridView1.RenderControl(hw);
Response.Write(style);
Response.Output.Write(sw.ToString());
Response.Flush();
Response.End();

public override void VerifyRenderingInServerForm(Control GridView1)
  {

      /* Verifies that the control is rendered */

  }

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