从代码隐藏中获取隐藏字段值

Question

我正在尝试分配隐藏字段值，如 page_load 所示：

If Session("tempDir") Is Nothing Then
    If Request.Files.Count > 0 Then
        Dim tempDir As String
        tempDir = Path.GetRandomFileName()
        tempDir = tempDir.Substring(0, tempDir.LastIndexOf("."))
        IO.Directory.CreateDirectory(Server.MapPath("~/Uploads/" & tempDir))
        IO.Directory.CreateDirectory(Server.MapPath("~/Downloads/" & tempDir))
        Session.Add("tempDir", tempDir)


        currentDirectory.Value = Session("tempDir").ToString

        Dim chunk As Integer = If(Context.Request("chunk") IsNot Nothing, Integer.Parse(Context.Request("chunk")), 0)
        Dim fileName As String = If(Context.Request("name") IsNot Nothing, Context.Request("name"), String.Empty)
        myfilename = fileName
        Session.Add("filename", myfilename)
        finalfilename.Value = currentDirectory.Value & fileName

        finalfilename.Value = Session("filename").ToString
        MsgBox(finalfilename.Value)

        workingDir.Value = Server.MapPath("~/Uploads/" & tempDir)
        Session.Add("tempDir", workingDir.Value)
        MsgBox(workingDir.Value)


        waitFlag.Value = "True"
        Session.Add("flag", waitFlag.Value)

        waitFlag.Value = Session("flag").ToString
        MsgBox(waitFlag.Value)

        Dim fileUpload As HttpPostedFile = Context.Request.Files(0)

        Dim uploadPath = Context.Server.MapPath("~/uploads/" & tempDir)
        Using fs = New FileStream(Path.Combine(uploadPath, fileName), If(chunk = 0, FileMode.Create, FileMode.Append))
            Dim buffer = New Byte(fileUpload.InputStream.Length - 1) {}
            fileUpload.InputStream.Read(buffer, 0, buffer.Length)

            fs.Write(buffer, 0, buffer.Length)
        End Using
    End If
End If

这些是我的 html 输入隐藏字段：

<input type="hidden" id="workingDir" runat="server"/>
<input type="hidden" id="finalfilename" runat="server"/>
<input type="hidden" id="waitFlag"  runat="server"/>
<input id="currentDirectory" type="hidden" runat="server"/>

这是我的 ajax 调用，我将所有隐藏字段值设为未定义：

<script type="text/javascript">
     $('#btnconvert').click(function () {
         var wd = $('#workingDir').val();
         alert(wd);
         var fn = $('#finalfilename').val();
         alert(fn);
         var bf = $('#waitFlag').val();
         alert(bf);
         $.ajax({
             type: "POST",
             url: "Default.aspx/ProcessFiles",
             data: "{'workingDir':'" + wd + "', 'finalfilename':'" + fn + "', 'waitFlag':'" + bf + "'}",
             contentType: "application/json; charset=utf-8",
             dataType: "json",
             success: function (data) {
                 alert("success");
             },
             error: function (data) {
                 alert("fail");
             }
         });
     });
  </script>

谁能指出我哪里出错了？

Answer 1

你犯了一些小错误。

问题在于您从隐藏字段中检索值的 Jquery 按钮单击事件。您的隐藏字段是服务器端控制。所以在渲染的时候，隐藏字段的id不会只有workingDir, finalfilename, waitFlag

所以你应该使用 ClientID 从 Hidden Field 获取值，如下所述：

var wd = $('#<%=workingDir.ClientID%>').val();
alert(wd);
var fn = $('#<%=finalfilename.ClientID%>').val();
alert(fn);
var bf = $('#<%=waitFlag.ClientID%>').val();
alert(bf);

您的 JQUERY 如下所示：

<script type="text/javascript">
        $('#btnconvert').click(function () {
            var wd = $('#<%=workingDir.ClientID%>').val();
            alert(wd);
            var fn = $('#<%=finalfilename.ClientID%>').val();
            alert(fn);
            var bf = $('#<%=waitFlag.ClientID%>').val();
            alert(bf);
            $.ajax({
                type: "POST",
                url: "Default.aspx/ProcessFiles",
                data: "{'workingDir':'" + wd + "', 'finalfilename':'" + fn + "', 'waitFlag':'" + bf + "'}",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (data) {
                    alert("success");
                },
                error: function (data) {
                    alert("fail");
                }
            });
        });
</script>