你好，我想通过下拉列表从数据库下载文件，这些文件以前已上传到服务器(数据库) [英] hello i want to download a file from database through dropdownlist what have peviously upload into sever(databse)

问题描述

你好

我想下载以前上传的文件.

我有一个包含以下内容的asp.net应用程序.

一个ID文本框和一个用于上载文档的文件上载控件，以及一个用于上载文档的按钮，我也使用一个文件夹名称在我的网站中上载

我创建了一个数据库
EID整数主键
EFilename nvarchar(100)

然后，我编写了用于在button_click中上传文件的编码.

Hello

I want to download a file what i have previously uploaded.

I have an asp.net application that contain.

One textbox for id and one fileupload control for upload document and one button for upload document and also i take one folder name Upload in my website

I am created a database
Eid integer primary key
EFilename nvarchar(100)

Then i write coding for upload the file in button_click.

using System.Data.SqlClient
 SqlConnection con;
        con = new SqlConnection("Server=DELL\\SQLEXPRESS;database=Student;integrated security=true");
        con.Open();
        string ph = "~/Upload/" + FileUpload1.FileName;
        FileUpload1.SaveAs(MapPath(ph));
        string str = "insert into upload values('" + TextBox1.Text + "','" + ph + "')";
        SqlCommand cmd = new SqlCommand(str, con);
        cmd.ExecuteNonQuery();
        Response.Write("Value inserted");
        con.Close();

然后，文件的路径将存储在数据库中，而物理文件将存储在Upload文件夹中

现在我想下载一个我上传到数据库的文件.

为此

我从该网站上获取了另一个Web站点，该Web表单包含一个下拉列表，用于选择要下载的文件
并通过dropdownlist与数据库绑定，我也可以通过一个按钮进行下载

我在button_click中编写了以下代码以下载

Then the path of file will be stored in data base.and physical file will be stored in Upload folder

Now i want download a file what i have uploaded into database.

for that

i have taken another webfrom on that website that web form contain one dropdownlist for select file what u want to download
and also bind with database with dropdownlist and i have take one button also for downloading

i have write following a code in button_click for downloading

string fname = DropDownList1.SelectedItem.Text;
    string filepath = Server.MapPath(@"~\Upload\" + fname);
    FileInfo fi = new FileInfo(filepath);
    if (fi.Exists )
    {
        Response.ClearContent();
        Response.AddHeader("Content-Disposition", "attachment;filename=" + fname);
        Response.AddHeader("Content-Length", fi.Length.ToString());
        Response.ContentType = "application";
        Response.TransmitFile(fi.FullName);
        Response.End();
    }

它仅适用于dropdpwnlist item [0]元素，只能下载


但不适用于下拉列表中的其余项目

当我选择下拉列表项目[1]时，项目[0]仅下载
所以我能做的

给我你的建议

问候
Reshma

it''s working only for dropdpwnlist item[0] element can only downloaded


but not working for remaining items in dropdownlist

when i selcted the dropdownlist item[1] then the item[0] only downloaded
so what i can do

send me u suggestion

Regrds
Reshma

推荐答案

OT-您存储的文件路径逻辑不是很好-如果其他人上传具有相同名称的文件，您将覆盖现有文件并将原始记录指向错误的文件.

至少我会得到一些涉及使用DateTime或Guid的逻辑的信息，如果需要，您可以在数据库中添加一个额外的列，其中包含用于显示目的的原始文件名.

OT - Your stored file path logic is not very good - what happens if someone else uploads a file with the same name, you will overwrite the existing file and make the original record point to an incorrect file.

As a minimum I would got for some logic that involves using either the DateTime or a Guid, if required you can add an extra column to your database that contains the original filename for display purposes.

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