Question

为什么以下警告始终显示为空？

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Keyup._Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title></title>

<%--    <script src="JQuery/jquery-1.4.1.js" type="text/javascript"></script>--%>
            <script type="text/javascript">

                document.onkeyup = onkeyupOfDocument;

                function onkeyupOfDocument(evt) {
                    //var MultiView = $("*[id$='TextBox1']"); 
                    var MultiView = document.getElementById("MultiView1");
                    alert(MultiView);
                }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:MultiView ID="MultiView1" runat="server" ActiveViewIndex="0">
            <asp:View ID="View1" runat="server">
                    <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
            </asp:View>
            <asp:View ID="View2" runat="server">
            </asp:View>
        </asp:MultiView>
    </div>
    </form>
</body>
</html>

解决null问题后，如何使用JavaScript或jQuery检查ActiveViewIndex？

似乎

if(MultiView.ActiveViewIndex == 0)

不是真的!!

提前致谢。

Answer 1

我们的页面完全加载到浏览器＆amp;查看源代码，我们可以说在仅使用javascrip或jquery的asp.net中更改（不检查）常规MultiView的ActiveViewIndex是不可能的。因为MultiView1 id没有元素 - ＆gt;只是一个div存在。

我们只能检查MultiView1的ActiveViewIndex，因为Nathan通过以下代码回答：

var activeViewIndex = <%=MultiView1.ActiveViewIndex %>;

请参阅以下链接了解更多信息（最新文章）：
MultiView Is A reach Element
因此下面的代码没有任何意义：

var MultiView = document.getElementById("<%=MultiView1.ClientID %>");

如果您想在客户端更改（不检查）ActiveViewIndex，则有一个技巧 - ＆gt;请看下面的代码：

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
    protected void butSubmit_Click(object sender, EventArgs e)
    {
        MultiView1.ActiveViewIndex = int.Parse(HiddenField1.Value);
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Demo</title>

    <script language="javascript" type="text/ecmascript">
    function OnClientClick( ServerControID,IndexControlID, Index){
        var objDemo = document.getElementById(ServerControID);
        if(objDemo){
            document.getElementById(IndexControlID).value = Index;
            objDemo.click();                        
        }        
    }
    </script>

</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:MultiView ID="MultiView1" runat="server" ActiveViewIndex="0">
                <asp:View ID="View1" runat="server">
                    <span style="color: #ff0000; background-color: #33ccff"><strong>Hi, I am View 1</strong></span></asp:View>
                <asp:View ID="View2" runat="server">
                    <strong><span style="color: background; background-color: #99ff00">Hi, I am View 2</span></strong></asp:View>
            </asp:MultiView></div>
        <asp:HiddenField ID="HiddenField1" runat="server" />
        <input id="btnShow1" type="button" value="Show View 1" onclick="OnClientClick('butSubmit','HiddenField1','0')" />
        <input id="btnShow2" type="button" value="Show View 2" onclick="OnClientClick('butSubmit','HiddenField1','1')" />
        <div style="display: none">
            <asp:Button ID="butSubmit" runat="server" OnClick="butSubmit_Click" Text="Submit" /></div>
    </form>
</body>
</html>

这里是页面加载后的高位代码的源代码，即9：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">



<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1"><title>
    Demo
</title>

    <script language="javascript" type="text/ecmascript">

        function OnClientClick(ServerControID, IndexControlID, Index) {
            var objDemo = document.getElementById(ServerControID);
            if (objDemo) {
                document.getElementById(IndexControlID).value = Index;
                objDemo.click();
            }
        }
    </script>

</head>
<body>
    <form method="post" action="WebForm3.aspx" id="form1">
<div class="aspNetHidden">
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="/wEPDwUIODMxNDI3MTNkGAEFCk11bHRpVmlldzEPD2RmZJjYXp6H2AsOwVGwRlIRlk0x9agdyp/Kg++cmPNXKpTg" />
</div>

<div class="aspNetHidden">

    <input type="hidden" name="__EVENTVALIDATION" id="__EVENTVALIDATION" value="/wEWAgKrwZG1BAKQo8KrDX7rF3izcHDs+E9bwpx3GnVGoIZVi2Gpv0IOOu9xXNMo" />
</div>
        <div>

                    <span style="color: #ff0000; background-color: #33ccff"><strong>Hi, I am View 1</strong></span></div>
        <input type="hidden" name="HiddenField1" id="HiddenField1" value="1" />
        <input id="btnShow1" type="button" value="Show View 1" onclick="OnClientClick('butSubmit','HiddenField1','0')" />
        <input id="btnShow2" type="button" value="Show View 2" onclick="OnClientClick('butSubmit','HiddenField1','1')" />
    </form>
</body>
</html>

Answer 2

更改

var MultiView = document.getElementById("MultiView1");

到

var MultiView = document.getElementById("<%=MultiView1.ClientID %>");

警报始终为空的原因是客户端上没有名为MultiView1的元素：这是控件的服务器端 ID。

要获取客户端的活动视图索引，请使用：

var activeViewIndex = <%=MultiView1.ActiveViewIndex %>;

Asp.net MultiView /使用Javascript或jQuery检查ActiveViewIndex

2 个答案: