blocks|key|2092904|text|//+using+System.Linq;

//+Considering+that+items+are+of+ListItem+type,+otherwise+use+Cast<ListItem>()
if+(!cblCustomerList.Items.Any(i+=>+i.Selected))
{
++++//+TODO:+Warn+an+user
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2092905|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>// using System.Linq;

// Considering that items are of ListItem type, otherwise use Cast&lt;ListItem&gt;()
if (!cblCustomerList.Items.Any(i =&gt; i.Selected))
{
    // TODO: Warn an user
}
</code></pre>


blocks|key|811536|text|if(cblCustomerList.Items.Cast<ListItem>().Any(item+=>+item.Selected))
{
+++//+at+least+one+selected
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|811537|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>if(cblCustomerList.Items.Cast&lt;ListItem&gt;().Any(item =&gt; item.Selected))
{
   // at least one selected
}
</code></pre>


blocks|key|2092943|text|试试这个；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2092944|boolean+b+=+cblCustomerList.Items.Cast<ListItem>().Any(i+=>+i.Selected)|code-block|syntax|javascript|2092945|如果b为true，则在checkboxlist列表中至少选择了一个。|offset|length|style|CODE|2092946|不要忘记使用System.Linq名称空间。|2092947|entityMap^0|0|0|2|1|4|4|0|6|B|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]|$I|V|J|W|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|X|8|@$I|Y|J|Z|K|L]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|10|8|@]|9|@]|A|$]]]|P|$]]

<p>Try this;</p>

<pre><code>boolean b = cblCustomerList.Items.Cast&lt;ListItem&gt;().Any(i =&gt; i.Selected)
</code></pre>

<p>if <code>b</code> is <code>true</code>, at least one is selected in your checkboxlist.</p>

<p>Don't forget to use <code>System.Linq</code> namespace.</p>


blocks|key|2092961|text|编辑：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2092962|下面是一个示例代码。这对我很有效|2092963|必须添加此脚本文件:<script+src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>|offset|length|style|CODE|2092964|+<%25@+Page+Language="C#"+AutoEventWireup="true"+CodeFile="Default.aspx.cs"+Inherits="_Default"+%25>

<!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="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
++++<script+type="text/javascript">
++++++++function+Validate_Checkbox()+{
++++++++++++var+chks+=+$("#<%25=+cblCustomerList.ClientID+%25>+input:checkbox");++++++++++

++++++++++++var+hasChecked+=+false;
++++++++++++for+(var+i+=+0;+i+<+chks.length;+i%2B%2B)+{
++++++++++++++++if+(chks[i].checked)+{
++++++++++++++++++++hasChecked+=+true;
++++++++++++++++++++break;
++++++++++++++++}
++++++++++++}
++++++++++++if+(hasChecked+==+false)+{
++++++++++++++++alert("Please+select+at+least+one+checkbox..!");

++++++++++++++++return+false;
++++++++++++}

++++++++++++return+true;
++++++++}+++++
++++</script>
</head>
<body>
++++<form+id="form1"+runat="server">
++++<div>
++++++++<asp:CheckBoxList+ID="cblCustomerList"+runat="server"+CssClass="CheckBoxList">
++++++++++++<asp:ListItem+Value="0">xx</asp:ListItem>
++++++++++++<asp:ListItem+Value="1">yy</asp:ListItem>
++++++++</asp:CheckBoxList>
++++++++<asp:Button+ID="xx"+runat="server"+OnClientClick="javascript:Validate_Checkbox();return+true;"+/>
++++</div>
++++</form>
</body>
</html>|code-block|syntax|javascript|2092965|而你改变了|2092966|<asp:CheckBoxList+ID="cblCustomerList"+runat="server"+DataSourceID="SqlDataSource1"+CssClass="CheckBoxList"+DataTextField="GroupName"+DataValueField="GroupName">+++++++++++++
++++++++++++</asp:CheckBoxList>|2092967|控件，而不是我的示例代码。并在按钮control.look中调用我的示例代码中的javascript+function。|2092968|切尔斯！|2092969|编辑|2092970|请添加此脚本文件|2092971|<script+src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>|2092972|代替<script+src="scripts/jquery-1.8.3.min.js"+type="text/javascript"></script>|2092973|entityMap^0|0|0|A|2A|0|0|0|0|14|J|0|0|0|0|0|2|22|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|17|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|18|8|@$F|19|G|1A|H|I]]|9|@]|A|$]]|$1|J|3|K|5|L|7|1B|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|1C|8|@]|9|@]|A|$]]|$1|Q|3|R|5|L|7|1D|8|@]|9|@]|A|$M|N]]|$1|S|3|T|5|6|7|1E|8|@$F|1F|G|1G|H|I]]|9|@]|A|$]]|$1|U|3|V|5|6|7|1H|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|1I|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|6|7|1J|8|@]|9|@]|A|$]]|$1|10|3|11|5|L|7|1K|8|@]|9|@]|A|$M|N]]|$1|12|3|13|5|6|7|1L|8|@$F|1M|G|1N|H|I]]|9|@]|A|$]]|$1|14|3|-4|5|6|7|1O|8|@]|9|@]|A|$]]]|15|$]]

<p>Edit:</p>

<p>Here is one sample code. its working to me</p>

<p>Must add this script file :<code>&lt;script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"&gt;&lt;/script&gt;</code></p>

<pre><code> &lt;%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %&gt;

&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
&lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
&lt;head runat="server"&gt;
    &lt;title&gt;&lt;/title&gt;
    &lt;script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"&gt;&lt;/script&gt;
    &lt;script type="text/javascript"&gt;
        function Validate_Checkbox() {
            var chks = $("#&lt;%= cblCustomerList.ClientID %&gt; input:checkbox");          

            var hasChecked = false;
            for (var i = 0; i &lt; chks.length; i++) {
                if (chks[i].checked) {
                    hasChecked = true;
                    break;
                }
            }
            if (hasChecked == false) {
                alert("Please select at least one checkbox..!");

                return false;
            }

            return true;
        }     
    &lt;/script&gt;
&lt;/head&gt;
&lt;body&gt;
    &lt;form id="form1" runat="server"&gt;
    &lt;div&gt;
        &lt;asp:CheckBoxList ID="cblCustomerList" runat="server" CssClass="CheckBoxList"&gt;
            &lt;asp:ListItem Value="0"&gt;xx&lt;/asp:ListItem&gt;
            &lt;asp:ListItem Value="1"&gt;yy&lt;/asp:ListItem&gt;
        &lt;/asp:CheckBoxList&gt;
        &lt;asp:Button ID="xx" runat="server" OnClientClick="javascript:Validate_Checkbox();return true;" /&gt;
    &lt;/div&gt;
    &lt;/form&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>

<p>and you change </p>

<pre><code>&lt;asp:CheckBoxList ID="cblCustomerList" runat="server" DataSourceID="SqlDataSource1" CssClass="CheckBoxList" DataTextField="GroupName" DataValueField="GroupName"&gt;             
            &lt;/asp:CheckBoxList&gt;
</code></pre>

<p>control  instead of  my sample code . and call the <code>javascript function</code> in the button control.look my sample code. </p>

<p>Chears!!!</p>

<p>Edit </p>

<p>please add this script file </p>

<pre><code>&lt;script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"&gt;&lt;/script&gt;
</code></pre>

<p>Instead of <code>&lt;script src="scripts/jquery-1.8.3.min.js" type="text/javascript"&gt;&lt;/script&gt;</code></p>


blocks|key|2092991|text|您只需使用cblCustomerList.SelectedItem+==+null，SelectedItem将返回选中项列表中最低序号的项，因此如果未返回任何内容，则不会检查任何内容。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2092992|http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.checkboxlist.aspx|2092993|entityMap|0|LINK|mutability|MUTABLE|url^0|5|10|0|0|2B|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|R|8|@]|D|@$9|S|A|T|1|U]]|E|$]]|$1|H|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|G]]]]

<p>You would just use <code>cblCustomerList.SelectedItem == null</code>, SelectedItem will return the lowest ordinal item in the list of checked items, so if nothing is returned, nothing is checked.</p>

<p><a href="http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.checkboxlist.aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.checkboxlist.aspx</a></p>


blocks|key|5445435|text|我能想到的最简单的方法...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5445436|public+void+alert()
++++++++{
++++++++++++int+i=0;
++++++++++++foreach+(ListItem+listItem+in+cblCustomerList.Items)
++++++++++++{
++++++++++++++++if+(listItem.Selected)
++++++++++++++++{
++++++++++++++++++++i%2B%2B;
++++++++++++++++}
++++++++++++}
++++++++++++if(i+!=0)
++++++++++++{
++++++++++++++++Response.Write("Please+check+at+least+one+option");
++++++++++++}
++++++++}
++++}|code-block|syntax|javascript|5445437|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>The simplest way i can think of....</p>

<pre><code>public void alert()
        {
            int i=0;
            foreach (ListItem listItem in cblCustomerList.Items)
            {
                if (listItem.Selected)
                {
                    i++;
                }
            }
            if(i !=0)
            {
                Response.Write("Please check at least one option");
            }
        }
    }
</code></pre>


blocks|key|5927663|text|++++++++if(!+cblCustomerList.Items.Cast<ListItem>().AsParallel().Any(i+=>+i.Selected))
++++++++{
+++++++++++ShowAlert("Please+select+at+least+one+option");
++++++++}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|5927664|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>        if(! cblCustomerList.Items.Cast&lt;ListItem&gt;().AsParallel().Any(i =&gt; i.Selected))
        {
           ShowAlert("Please select at least one option");
        }
</code></pre>


blocks|key|5445449|text|jQuery解决方案。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5445450|if+(!$(".CheckBoxList").find("input:checked").length)+{
++++alert("Houston,+we've+had+a+problem!");
}|code-block|syntax|javascript|5445451|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>jQuery solution.</p>

<pre><code>if (!$(".CheckBoxList").find("input:checked").length) {
    alert("Houston, we've had a problem!");
}
</code></pre>


blocks|key|811577|text|使用内置的“CheckedItems”：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|811578|+dim+x1+As+Integer+=+clbMoveTo.CheckedItems.Count
+If+x1+<=+0+Then
+++++MessageBox.Show("Select+Move+To.","Verify")
+++++return
++End+If|code-block|syntax|javascript|811579|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Using built-in 'CheckedItems':</p>
<pre><code> dim x1 As Integer = clbMoveTo.CheckedItems.Count
 If x1 &lt;= 0 Then
     MessageBox.Show(&quot;Select Move To.&quot;,&quot;Verify&quot;)
     return
  End If
</code></pre>


<p>I have checkboxlist and I would like to check if at least one checkbox is checked.  If none is checked then I want to show alert message that says please select at least one item.  I want to do this in code behind if possible.  I have started but don't know if it is right or wrong but not able to finish it. </p>

<pre><code> public void alert()
    {
        foreach (ListItem listItem in cblCustomerList.Items)
        {
            if (!listItem.Selected)
            {
            }
        }
    }
</code></pre>

<p>here is the checkboxlist in aspx:</p>

<pre><code> &lt;asp:CheckBoxList ID="cblCustomerList" runat="server" DataSourceID="SqlDataSource1" CssClass="CheckBoxList"
            DataTextField="GroupName" DataValueField="GroupName" 
                onclick="readCheckBoxList()" &gt;               
            &lt;/asp:CheckBoxList&gt;
</code></pre>

<p>here is the button:</p>

<pre><code> &lt;asp:Button ID="Button1" runat="server" CausesValidation="True" 
                            CommandName="Insert" Text="Insert" OnClientClick="return Validate_Checkbox()" /&gt;
</code></pre>

<p>Thanks for your help.</p>


Check if at least one checkboxlist is selected

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有checkboxlist，我想检查是否至少选中了一个复选框。如果未选中，则我希望显示警告消息，提示请至少选择一个项目。如果可能的话，我想在后台代码中做这件事。我已经开始了，但不知道它是对还是错，但无法完成它。 public void alert()    {        foreach (ListItem lis...

问检查是否至少选择了一个检查框列表
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