在c#dons'；中编辑并提交图像；t工作

我添加了上传图像字段，并将其存储在数据库（保存路径）和硬盘驱动器（图像）中。

当我编辑图片字段并提交时，它没有提交，而是在警报中显示"上传你的图片"。

所以我想我需要检查图像是否包括在硬盘驱动器或数据库中的图像路径中。

我不能这样做，因为我在.net上更新鲜。

这是我的密码；

     <tr>
            <td>
            <asp:Label ID="Label4" runat="server" Text="Image"></asp:Label>
            </td>
            <td>
            &nbsp;
        </td>
        <td>
            <asp:Image ID="Image1" runat="server" ControlStyle-Width="50" ControlStyle-Height = "50"  />
        </td>
        <td>
        <asp:FileUpload ID="fileupload" runat="server" />  
         </td>
        </tr>
        <tr>
        <td>
            <asp:Button ID="btnsub" runat="server" Text="Submit" OnClick="btnsub_Click" OnClientClick="return register();" />
            <asp:Button ID="btnrst" runat="server" Text="Reset" OnClick="btnrst_Click" />
        </td>
</tr>

cs:

protected void btnsub_Click(object sender, EventArgs e)
        {
            SqlConnection con = Connection.DBconnection();
            if (Textid.Text.Trim().Length > 0)
            {
                SqlCommand com = new SqlCommand("StoredProcedure3", con);
                com.CommandType = CommandType.StoredProcedure;
                com.Parameters.AddWithValue("@id", Textid.Text.Trim());
                com.Parameters.AddWithValue("@Name", Textusername.Text.Trim());
                com.Parameters.AddWithValue("@Class", Textclass.Text.Trim());
                com.Parameters.AddWithValue("@Section", Textsection.Text.Trim());
                com.Parameters.AddWithValue("@Address", Textaddress.Text.Trim());
                try
                {
                    string filename = string.Empty;
                    if (fileupload.PostedFile.FileName.Length > 0)
                    {
                        filename = Path.GetFileName(fileupload.PostedFile.FileName);
                        fileupload.SaveAs(Server.MapPath("~/Images/" + filename));
                    }                    
                    com.Parameters.AddWithValue("@Image",(filename.Length>0)? "Images/" + filename:string.Empty);
                    com.ExecuteNonQuery();                    
                }
                catch (Exception ex)
                {
                    btnsub.Text = ex.Message;
                }
                Response.Redirect("studententry.aspx");
            }
            else
            {
                SqlCommand com = new SqlCommand("StoredProcedure1", con);
                com.CommandType = CommandType.StoredProcedure;
                com.Parameters.AddWithValue("@Name", Textusername.Text.Trim());
                com.Parameters.AddWithValue("@Class", Textclass.Text.Trim());
                com.Parameters.AddWithValue("@Section", Textsection.Text.Trim());
                com.Parameters.AddWithValue("@Address", Textaddress.Text.Trim());
                try
                {
                    string filename = string.Empty;
                    if (fileupload.PostedFile.FileName.Length > 0)
                    {
                        filename = Path.GetFileName(fileupload.PostedFile.FileName);
                        fileupload.SaveAs(Server.MapPath("~/Images/" + filename));
                    }
                    com.Parameters.AddWithValue("@Image",(filename.Length>0)? "Images/" + filename:string.Empty);
                    com.ExecuteNonQuery();                    
                }
                catch (Exception ex)
                {
                    btnsub.Text = ex.Message;
                }
                Response.Redirect("studententry.aspx");
            }
        }
        protected void btnrst_Click(object sender, EventArgs e)
        {
            Textid.Text = string.Empty;
            Textusername.Text = string.Empty;
            Textclass.Text = string.Empty;
            Textsection.Text = string.Empty;
            Textaddress.Text = string.Empty;
            Image1.ImageUrl = string.Empty;
        }
        protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
        {
            SqlConnection con = Connection.DBconnection();
            if (e.CommandName == "EditRow")
            {            
                GridViewRow gr = (GridViewRow)((Button)e.CommandSource).NamingContainer;
                int index = gr.RowIndex; 
                hiddenfield.Value = index.ToString(); 
                Textid.Text = gr.Cells[0].Text;
                Textusername.Text = gr.Cells[1].Text;
                Textclass.Text = gr.Cells[2].Text;
                Textsection.Text = gr.Cells[3].Text;
                Textaddress.Text = gr.Cells[4].Text;                
                Image1.ImageUrl = ((System.Web.UI.WebControls.Image)gr.Cells[5].Controls[0]).ImageUrl;                    
            }
            else if (e.CommandName == "Deleterow")
            {
                SqlCommand com = new SqlCommand("StoredProcedure4", con);
                com.CommandType = CommandType.StoredProcedure;
com.Parameters.AddWithValue("@ID", Convert.ToInt32(e.CommandArgument));
                var id = Int32.Parse(e.CommandArgument.ToString());                
                com.ExecuteNonQuery();
                Response.Redirect("studententry.aspx");
            }
        }
        protected void GridView1_SelectedIndexChanged(Object sender, EventArgs e)
        {
            int index = GridView1.SelectedIndex;
            hiddenfield.Value = index.ToString();
        }

验证：

function register() {if (document.getElementById("<%=fileupload.ClientID%>").value == "") {
            alert("Upload Your image !");
            document.getElementById("<%=fileupload.ClientID%>").focus();
            return false;
        }
    }

           function register() {
             if (document.getElementById("<%=hiddenfield.ClientID%>").value == "") { 
                if (document.getElementById("<%=fileupload.ClientID%>").value == "") { 
                alert("Upload Your image !"); 
                document.getElementById("<%=fileupload.ClientID%>").focus(); return false; 
                }
             }         
          }