I inserted binary files (images, PDF, videos..) and I want to retrieve this file to download it.
I used generic handler page as this
public void ProcessRequest (HttpContext context) {
using (System.Data.SqlClient.SqlConnection con = Connection.GetConnection())
{
String Sql = "Select BinaryData From ProductsDownload Where Product_Id = @Product_Id";
SqlCommand com = new SqlCommand(Sql, con);
com.CommandType = System.Data.CommandType.Text;
com.Parameters.Add(Parameter.NewInt("@Product_Id", context.Request.QueryString["Product_Id"].ToString()));
SqlDataReader dr = com.ExecuteReader();
if (dr.Read() && dr != null)
{
Byte[] bytes;
bytes = Encoding.UTF8.GetBytes(String.Empty);
bytes = (Byte[])dr["BinaryData"];
context.Response.BinaryWrite(bytes);
dr.Close();
}
}
}
and this is my table
CREATE TABLE [ProductsDownload] (
[ID] [bigint] IDENTITY (1, 1) NOT NULL ,
[Product_Id] [int] NULL ,
[Type_Id] [int] NULL ,
[Name] [nvarchar] (200) COLLATE Arabic_CI_AS NULL ,
[MIME] [varchar] (50) COLLATE Arabic_CI_AS NULL ,
[BinaryData] [varbinary] (4000) NULL ,
[Description] [nvarchar] (500) COLLATE Arabic_CI_AS NULL ,
[Add_Date] [datetime] NULL ,
CONSTRAINT [PK_ProductsDownload] PRIMARY KEY CLUSTERED
(
[ID]
) ON [PRIMARY] ,
CONSTRAINT [FK_ProductsDownload_DownloadTypes] FOREIGN KEY
(
[Type_Id]
) REFERENCES [DownloadTypes] (
[ID]
) ON DELETE CASCADE ON UPDATE CASCADE ,
CONSTRAINT [FK_ProductsDownload_Product] FOREIGN KEY
(
[Product_Id]
) REFERENCES [Product] (
[Product_Id]
) ON DELETE CASCADE ON UPDATE CASCADE
) ON [PRIMARY]
GO
And use data list has label for file name and button to download file as
<asp:DataList ID="DataList5" runat="server"
DataSource='<%#GetData(Convert.ToString(Eval("Product_Id")))%>'
RepeatColumns="1" RepeatLayout="Flow">
<ItemTemplate>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td class="spc_tab_hed_bg spc_hed_txt lm5 tm2 bm3">
<asp:Label ID="LblType" runat="server" Text='<%# Eval("TypeName", "{0}") %>'></asp:Label>
</td>
<td width="380" class="spc_tab_hed_bg">
开发者_高级运维
</td>
</tr>
<tr>
<td align="left" class="lm5 tm2 bm3">
<asp:Label ID="LblData" runat="server" Text='<%# Eval("Name", "{0}") %>'></asp:Label>
</td>
<td align="center" class=" tm2 bm3">
<a href='<%# "DownloadFile.aspx?Product_Id=" + DataBinder.Eval(Container.DataItem,"Product_Id") %>' >
<img src="images/downloads_ht.jpg" width="11" height="11" border="0" />
</a>
<%--<asp:ImageButton ID="ImageButton1" ImageUrl="images/downloads_ht.jpg" runat="server" OnClick="ImageButton1_Click1" />--%>
</td>
</tr>
</table>
</ItemTemplate>
</asp:DataList>
I tried more to solve this problem but I cannot.
Although you could work on your question to narrow it down, I'm guessing your browser does not recognize it as a file to download instead of trying to show it?
It's because your just sending bytes as a result, you should tell the browser what data is coming back from the server. The way to do that is to set the content headers.
// optionally provide the filename instead of
// letting the browser create one based on the get url
context.Response.AddHeader("content-disposition", "attachement filename=" + dr["Name"]);
// set the MIME content type of the data.
context.Response.ContentType = dr["MIME"];
I don't remember if you need to do a typecast on the dr["MIME"]
result to get a String, but that's left for the implementer.
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