javascript判断是否有对RadioButtonList选项选择

写Javascript来判断是否有对RadioButtonList选项选择，效果如下：



准备好RadioButtonList数据源：
Cosmetic.vb

Imports Microsoft.VisualBasic 
Namespace Insus.NET 
Public Class Cosmetic 
Private _ID As Integer 
Private _Type As String 
Private _Name As String 
Private _Weight As Decimal 
Private _UM As String 
Public Property ID As Integer 
Get 
Return _ID 
End Get 
Set(value As Integer) 
_ID = value 
End Set 
End Property 
Public Property Type As String 
Get 
Return _Type 
End Get 
Set(value As String) 
_Type = value 
End Set 
End Property 
Public Property Name As String 
Get 
Return _Name 
End Get 
Set(value As String) 
_Name = value 
End Set 
End Property 
Public Property Weight As Decimal 
Get 
Return _Weight 
End Get 
Set(value As Decimal) 
_Weight = value 
End Set 
End Property 
Public Property UM As String 
Get 
Return _UM 
End Get 
Set(value As String) 
_UM = value 
End Set 
End Property 
Public Sub New() 
End Sub 
Public Sub New(id As Integer, type As String, name As String, weight As Decimal, um As String) 
Me._ID = id 
Me._Type = type 
Me._Name = name 
Me._Weight = weight 
Me._UM = um 
End Sub 
Public Function GetData() As List(Of Cosmetic) 
Dim o As New List(Of Cosmetic) 
Dim c As New Cosmetic(1, "滋润霜", "玉兰油", 50, "g") 
o.Add(c) 
Dim c1 As New Cosmetic(2, "滋润霜", "雅诗兰黛", 100, "g") 
o.Add(c1) 
Dim c2 As New Cosmetic(3, "滋润霜", " 兰蔻", 80, "g") 
o.Add(c2) 
Dim c3 As New Cosmetic(4, "滋润霜", "欧莱雅", 60, "g") 
o.Add(c3) 
Dim c4 As New Cosmetic(5, "滋润霜", "芭比波朗", 120, "g") 
o.Add(c4) 
Return o 
End Function 
End Class 

End Namespace

在aspx放一个RadioButtonList控件和一个铵钮：

化妆品：<asp:RadioButtonList ID="RadioButtonListCosmetic" runat="server" RepeatColumns="10" RepeatDirection="Horizontal"></asp:RadioButtonList> 
<br /> 
<asp:Button ID="Button1" runat="server" Text="Select" />

在aspx.vb中，为RadioButtonList绑定数据源，当然绑定数据源下面的代码中，还得引用命名空间 Imports Insus.NET

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load 
If Not IsPostBack Then 
Data_Binding() 
End If 
End Sub 
Private Sub Data_Binding() 
Dim objCosmetic As New Cosmetic() 
Me.RadioButtonListCosmetic.DataSource = objCosmetic.GetData() 
Me.RadioButtonListCosmetic.DataTextField = "Name" 
Me.RadioButtonListCosmetic.DataValueField = "ID" 
Me.RadioButtonListCosmetic.DataBind() 
End Sub

接下来是演示开始，写Javascript代码：

View Code 
<script type="text/javascript"> 
function CheckIsSelected() { 
var rbl = document.getElementById("<%=RadioButtonListCosmetic.ClientID%>"); 
var radio = rbl.getElementsByTagName("input"); 
var isSelect = false; 
for (var i = 0; i < radio.length; i++) { 
if (radio[i].checked) { 
isSelect = true; 
break; 
} 
} 
if (!isSelect) { 
alert("请选择一个选项。"); 
} 
return isSelect; 
} 
</script>

最后是为铵钮Button写客户端事件

<asp:Button ID="Button1" runat="server" Text="Select" OnClientClick="return CheckIsSelected()" />