Question

我需要上传文件。文件上传时我需要显示进度条。但当我点击updatepanel中的上传按钮时，fileupload中的文件会在我添加触发器时消失，文件将上传但进度条将不会显示这是我的代码

<%@ Page Title="" Language="C#" MasterPageFile="~/site.Master" AutoEventWireup="true" CodeBehind="upload.aspx.cs" Inherits="fix_asset.upload" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
    <style type="text/css">
        .auto-style2 {
            height: 23px;
        }
    </style>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
    <asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <table style="margin:auto; padding-top:50px">
                <tr>
                    <td style="font-weight: 600; font-size: large; background-color: #0000FF; border: thin solid #000000">
                        UPLOAD MASTER FILE
                    </td>
                </tr>
                <tr style="border: thin solid #000000; background-color: #DBD5FD;">
                    <td>
                        <table>
                            <tr>
                                <td style="width:100px">
                                    Location
                                </td>
                                <td>
                                    <asp:FileUpload ID="FileUpload1" runat="server" />
                                </td>
                                <td style="width:100px">
                                    <asp:Button ID="Button1" runat="server" Text="Upload" OnClick="Button1_Click" OnClientClick="uploadfile()" style="width:100px" />
                                </td>
                                <td style="width:100px">
                                    <asp:Button ID="Button2" runat="server" Text="Sampling" OnClick="Button2_Click" style="width:100px" />
                                </td>

                            </tr>
                            <tr>
                                <td colspan="4" style="text-align:center" class="auto-style2">
                                    <asp:Label ID="lblNotification" runat="server" Text=""></asp:Label>
                                </td>
                            </tr>
                        </table>
                    </td>
                    </tr>
            </table>
            <asp:HiddenField ID="HiddenField1" runat="server" />
            <asp:Button ID="Button4" runat="server" Text="Button" style="visibility:hidden" OnClick="Button4_Click" />
            <asp:HiddenField ID="HiddenField2" runat="server" />
            <br />
            <hr />
            <br />

        </ContentTemplate>
    </asp:UpdatePanel>
                <table style="margin:auto; padding-top:50px; width:560px; border-collapse: collapse;">
                <tr style="font-weight: 600; font-size: large; background-color: #0000FF; border: thin solid #000000">
                    <td colspan="3" >VLOOK UPLOAD</td>
                </tr>
                <tr style="border: thin solid #000000; background-color: #DBD5FD; padding:5px 5px 5px 5px">
                    <td>
                        Location
                    </td>
                    <td>
                        <asp:FileUpload ID="FileUpload2" runat="server" style="width:100%" />
                    </td>
                    <td>
                        <asp:Button ID="Button3" runat="server" style="width:100%" Text="Upload" onclick="Button3_Click" OnClientClick="uploadfile2()" />
                    </td>
                </tr>
                <tr>
                    <td colspan="3">
                        <asp:Label ID="lblNotification2" runat="server" Text=""></asp:Label>
                    </td>
                </tr>
                
            </table>
    <script>
        function uploadfile() {
            document.getElementById('<%= HiddenField1.ClientID%>').value = document.getElementById('<%= FileUpload1.ClientID%>').value;
        }
        function uploadfile2() {
            document.getElementById('<%= HiddenField2.ClientID%>').value = document.getElementById('<%= FileUpload2.ClientID%>').value;
        }
    </script>
</asp:Content>

Answer 1

AJAX更新面板用于防止页面具有完整的回发。使用更新面板，我们可以进行部分页面回发。部分页面回发执行以下操作

1.提高应用程序的性能

2.减少应用程序的页面加载时间

3.减少应用程序和服务器之间的往返

4.只有网页中需要刷新的部分才能获得回发

我们知道我们可以使用文件上传控件将文件上传到服务器。但是，如果我们在更新面板中使用文件上传控件，则它不起作用。原因是文件上载控件不适用于异步回发。

将此添加到您的表单标记，然后添加触发器，如图所示

<form id="form1" runat="server" method="post" enctype="multipart/form-data" >
.....
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID = "uploadbuttonID"/>     
</Triggers>
</asp:UpdatePanel>
.....
</form>

参考此链接......

http://www.aspsnippets.com/Articles/Display-Show-ASPNet-AJAX-UpdateProgress-with-UpdatePanel-PostBackTrigger.aspx

上传文件丢失

1 个答案: