Question

好的，

基本上我已经能够使用asp.net和c＃将文件上传到SQL Server数据库。我可以在浏览器中查看它们没有问题但是当我下载它们时它们似乎丢失了它们的原始格式，例如Word文档丢失了docx扩展名，您必须选择手动将它们作为word文档打开。

到目前为止，这是我的代码

    //Method used to upload a file to the database
    protected void UploadBut_Click(object sender, EventArgs e)
    {
        Stream inpStream = DocumentsUploadControl.PostedFile.InputStream;
        BinaryReader br = new BinaryReader(inpStream);
        Byte[] size = br.ReadBytes ((int)inpStream.Length);

        using (SqlConnection conn = new SqlConnection("Data Source=conn\\sqlexpress;Initial Catalog=new catalog;Integrated Security=True"))
        {

            string sql = "INSERT INTO Attachments(AttachmentReferenceID, AttachmentType, Filename, AttachmentDescription, FileUploadedBy, UploadDate)" + 
                "values (@Reference, @Type, @Filename, @Descr, @UploadedBy, @UploadedDate)";

            using (SqlCommand cmd = new SqlCommand(sql, conn))
            {
                cmd.Parameters.AddWithValue("@Reference", ReferenceDDL.Text.Trim());
                cmd.Parameters.AddWithValue("@Type", DocumentsUploadControl.PostedFile.ContentType.ToString());
                cmd.Parameters.AddWithValue("@Filename", FilenameTB.Text.Trim());
                cmd.Parameters.AddWithValue("@Descr", size);
                cmd.Parameters.AddWithValue("@UploadedBy", Session["username"].ToString());
                cmd.Parameters.AddWithValue("@UploadedDate", DateTime.Now.Date.ToShortDateString());

                conn.Open();
                cmd.ExecuteNonQuery();
                conn.Close();

                Response.Redirect("Documents.aspx");
            }

        }

    }


    //listener used to download the file
    protected void lnkDownload_Click(object sender, EventArgs e)
    {
        LinkButton lnkbtn = sender as LinkButton;
        GridViewRow gvrow = lnkbtn.NamingContainer as GridViewRow;
        int fileId = Convert.ToInt32(DocumentsGridView.DataKeys[gvrow.RowIndex].Value.ToString());

        using (SqlConnection conn = new SqlConnection("Data Source=conn\\sqlexpress;Initial Catalog=new catalog;Integrated Security=True"))
        {
            string sql = "SELECT AttachmentReferenceID, AttachmentType, Filename, AttachmentDescription, FileUploadedBy, UploadDate FROM Attachments WHERE AttachmentID=@ID";

            using (SqlCommand cmd = new SqlCommand(sql, conn))
            {
                cmd.Parameters.AddWithValue("@ID", fileId);
                conn.Open();

                SqlDataReader dr = cmd.ExecuteReader();

                if (dr.Read())
                {
                    Response.ContentType = dr["AttachmentType"].ToString();
                    Response.AddHeader("Content-Disposition", "attachment;filename=\"" + dr["Filename"] + "\"");
                    Response.BinaryWrite((byte[])dr["AttachmentDescription"]);
                    Response.End();

                    conn.Close();
                }
            }
        }
    }

Answer 1

尝试将应用/附加到您的附件类型。即

Response.contenttype = "application/" + dr["attachmenttype"].ToString();

Answer 2

看起来（尽管我无法确定）为filename保存的值依赖于文本框（FilenameTB）中的使用类型，而不是磁盘上文件的名称？

如果您要查看PostedFile.FileName，我想您可以提取扩展名吗？

Answer 3

您需要将扩展/附件类型添加到Response.AddHeader代码，例如：

Response.AddHeader("Content-Disposition", "attachment;filename=\"" + dr["Filename"] + "." + dr["AttachmentType"].ToString());

请尝试这个。

由于

文件不能以正确的格式下载

3 个答案: