文件無法從文件夾下載

Question

我遇到文件下載問題。我有一個顯示文件名和下載該文件的鏈接的網格。 這是我的網格的代碼。

<asp:GridView ID="gv7" runat="server" AllowPaging="True" CssClass="tbl_green_parrot" 
PageSize="5" Width="100%" AutoGenerateColumns="False" EmptyDataText="No Scheme data available" DataKeyNames="FilePath" OnPageIndexChanging="gv7_PageIndexChanging"    onrowdatabound="gv7_RowDataBound"> 
    <AlternatingRowStyle CssClass="tbl_green_parrot1" /> 
<FooterStyle CssClass="tbl_green_parrotfoot" /> 
<PagerStyle CssClass="tbl_green_parrotpager" /> 
<SelectedRowStyle CssClass="tbl_green_parrotselect" /> 
<EmptyDataRowStyle CssClass="tbl_green_parrotempty" /> 
<Columns> 
    <asp:TemplateField HeaderText="File Name"> 
    <ItemTemplate> 
    <asp:HyperLink ID="lnkFile" Target="_blank" CausesValidation="false" runat="server" 
    Text='<%# Bind("DisplayName") %>' NavigateUrl='<%# Bind("FilePath") %>' /> 
    </ItemTemplate> 
    </asp:TemplateField> 
    <asp:TemplateField HeaderText="Download" ItemStyle-Width="25px" ItemStyle-HorizontalAlign="Center"> 
    <ItemTemplate> 
    <a id="lnkDLoad" href='<%# Bind("FilePath") %>' runat="server" target="_blank"> 
    <img src="Images/download.png" alt="Download" /> 
    </a> 
    </ItemTemplate> 
    <ItemStyle HorizontalAlign="Center" Width="25px" ></ItemStyle> 
    </asp:TemplateField> 
</Columns> 

在這裏，我綁定的文件路徑到<a>標籤。當我將該文件放在網站的同一個根文件夾中時，此代碼正在運行。但是，當我嘗試下載文件夾內的文件時，它不會下載。

下載背後的代碼：

DataTable new_dt = new DataTable(); 
    new_dt.Columns.Add("DisplayName"); 
    new_dt.Columns.Add("FileName"); 
    new_dt.Columns.Add("FilePath"); 
    string Query = "SELECT DisplayName,FilePath,Universal From DistScheme"; 
    dt = DataAccessLayer.DAL.getFromDataTable(Query); 
    string filename = ""; 
    if (dt.Rows.Count > 0) 
    { 
     for (int i = 0; i < dt.Rows.Count; i++) 
     { 
      DataRow new_dr = new_dt.NewRow(); 
      if (dt.Rows[i]["Universal"].ToString() == "False") 
      { 
       filename = DistributorID + "_" + dt.Rows[i]["FilePath"].ToString(); 
      } 
      else 
      { 
       filename = dt.Rows[i]["FilePath"].ToString(); 
      } 
      string filepath = Server.MapPath("Uploads/Scheme/") + filename; 
      if (File.Exists(filepath)) 
      { 
       new_dr["DisplayName"] = dt.Rows[i]["DisplayName"].ToString(); 
       new_dr["FileName"] = filename; 
       new_dr["FilePath"] = filepath; 
       new_dt.Rows.Add(new_dr); 
      } 
     } 
    } 
    gv7.DataSource = new_dt; 
    gv7.DataBind(); 

我該如何解決這個問題？

Answer 1

您的文件路徑應該從「http」開始。在文件路徑中包含完整路徑，如http://domian-name/foldername/filename，並帶有擴展名。

Answer 2

要完成您的任務，即從網格下載文件，您需要在網格中添加以下模板列，如下所示。

<asp:TemplateField HeaderText="File" SortExpression="File Path"> 
       <ItemTemplate>      
        <asp:ImageButton ImageUrl="Images/download.png" ID="imgbtnDownload" runat="server" CommandName="DOWNLOAD" Text="GetFile" CommandArgument='<%# Bind("FilePath") %>' ></asp:ImageButton> 
       </ItemTemplate> 
      </asp:TemplateField> 

需要添加Row_command事件如下面的代碼後面的文件。

protected void gv7_RowCommand(object sender, GridViewCommandEventArgs e) 
{ 
    if (e.CommandName == "DOWNLOAD") 
    { 
    // make sure fileName contains only file name like 'test.pdf' 
     string fileName = Convert.ToString(e.CommandArgument); 

    // make sure filePath contains file path like 'Uploads/Scheme/test.pdf'   
     string filePath = Server.MapPath(Convert.ToString(e.CommandArgument)); 

     Response.Clear(); 
     Response.Buffer = true; 

     // Read the original file from disk 
     FileStream myFileStream = new FileStream(filePath, FileMode.Open); 
     long FileSize = myFileStream.Length; 
     byte[] Buffer = new byte[Convert.ToInt32(FileSize)]; 
     myFileStream.Read(Buffer, 0, Convert.ToInt32(FileSize)); 
     myFileStream.Close(); 
     // Tell the browse stuff about the file 
     Response.AddHeader("Content-Length", FileSize.ToString()); 
     //Response.AddHeader("Content-Disposition", "inline; filename=" & fileneme.Replace(" ", "_")) 
     Response.AddHeader("Content-Disposition", "attachment; filename=" + fileName + ";"); 
     //Response.TransmitFile(fileneme) 
     //Response.ContentType = getMimeType(sExtention, oConnection) 

     // Send the data to the browser 
     Response.BinaryWrite(Buffer); 
     Response.End(); 

    } 
} 

現在點擊圖片按鈕從aspx頁面，你可以得到打開或保存文件的選項。

希望這會幫助你...快樂編碼...