如何保持标签在Asp.net回发后的价值？ [英] How to maintain the value of label after postback in Asp.net?

问题描述

在asp.net页面，我需要知道如何保持由HTML按钮点击指定特定标签的值。后回传完成的。

In asp.net page I need to know how to maintain the value of a particular label assign by the html button click. After postback done.

详细code：

 <table>
        <tr>
            <td><asp:Label ID="lbl1" runat="server" ClientIDMode="Static">Before Changing</asp:Label></td>

            <td><asp:Label id="lbl2" runat="server" ClientIDMode="Static"></asp:Label></td>

            <td><asp:TextBox ID="txtbox" runat="server"></asp:TextBox></td>

</tr>

        <tr>
            <td><asp:Button ID="btnasp" runat="server"  Text="ASP Button" Height="50px" Width="150px" OnClick="btnasp_Click"/></td>

            <td><input type="button" id="btnhtml" value="HTML Button" onclick="showlabel()"  style="height:50px; width:150px"/></td>
        </tr>

    </table>

剧本

 <script type="text/javascript">
    function showlabel() {
        $('#lbl1').text("After Changing");

        }
</script>

CS code

cs code

   protected void btnasp_Click(object sender, EventArgs e)
    {

        txtbox.Text = lbl1.Text;
    }

输出

如果我点击HTML按钮改变之前，标签文字的变化改变了。然后我点击按钮ASP后更改值呈现在文本框。

If I click HTML button the label text before changing is change to after changing. Then I click the ASP button after changing value is show in textbox.

这是无隐藏字段添加值，而不是使用服务器控件的HTML按钮来完成。这怎么可能？

This is done without adding value in hidden field and not using the server control to html button. How is this possible?

推荐答案

的标签转换到跨度而像HTML元素跨度或 DIV 没有的ViewState 这些都不text / html文件被发送到服务器端的如格式元素。张贴在表单元素是输入元素和隐藏字段就是其中之一。在asp.net使用隐藏域维护的ViewState。恐怕你必须使用隐藏字段，以保持回发之间标签的值。

The label is converted in to span and the html element like span or div does not have ViewState neither the text/html of these is sent to server side like form elements. The form elements are posted are the input elements and hidden field is one of them. The asp.net maintain ViewState using hidden field. I am afraid you have to use hidden field to maintain the value of label between postbacks.

HTML

<input id="hdnLabelState" type="hidden" runat="server" >

的的JavaScript 的

document.getElementById('<%= hdnLabelState.ClientID %>').value = "changed value of span";

的服务器端（code后面）的

string changedLabelValue = hdnLabelState.Value;

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