Introduction: In previous
articles I explained How to Fill CheckBoxList from Sql Server table in asp.net(C#,VB) and Fill CheckBoxList based on DropDownList selection in asp.net(C#, VB) and How to get CheckBoxList selected items in comma separated format in asp.net(C#,VB) and Message box in asp.net website using JavaScript and how to redirect visitor from one website to another website using java script and How to call java script function from code behind file in asp.net Now in this article I am going to explain with example how to validate CheckBoxList control i.e. to ensure at least one item is selected in the CheckBoxList. I am using CustomValidator control and JavaScript to validate.
Implementation: Let's understand by an practical example.
- In the <HEAD> tag of the design page(.aspx) create the JavaScript function to validate the CheckBoxList.
function validateCheckBoxList(source, args) {
var chkListModules =
document.getElementById('<%= cblCourses.ClientID %>');
var chkListinputs =
chkListModules.getElementsByTagName("input");
for (var
i = 0; i < chkListinputs.length; i++) {
if (chkListinputs[i].checked) {
args.IsValid = true;
return;
}
}
args.IsValid = false;
}
</script>
- In the <Body> tag place a CheckBoxList, a Label control, a Button control and a CustomValidator control. In the CheckBoxList add some items as shown below:
<fieldset style="width:160px">
<legend>Select your skills</legend>
<asp:CheckBoxList ID="cblCourses"
runat="server"
RepeatColumns="2">
<asp:ListItem>Asp.net</asp:ListItem>
<asp:ListItem>C#</asp:ListItem>
<asp:ListItem>VB</asp:ListItem>
<asp:ListItem>WCF</asp:ListItem>
<asp:ListItem>Jquery</asp:ListItem>
<asp:ListItem>JavaScript</asp:ListItem>
</asp:CheckBoxList>
<asp:Label ID="lblStatus"
runat="server"
Text=""></asp:Label>
<asp:CustomValidator ID="CustomValidator1"
runat="server"
ErrorMessage="Please
select at least one skills." ClientValidationFunction
= "validateCheckBoxList"
Display="static"
ForeColor="Red"></asp:CustomValidator>
<asp:Button ID="btnSubmit"
runat="server"
Text="Submit"
onclick="btnSubmit_Click"
/>
</fieldset>
C#.Net Code to validate CheckBoxList using JavaScript
- In the code behind file(.aspx.cs) write the code as:
protected void btnSubmit_Click(object
sender, EventArgs e)
{
lblStatus.Text="Validation successful";
}
VB.Net Code to validate CheckBoxList using JavaScript
- In the code behind file(.aspx.vb) write the code as:
lblStatus.Text = "Validation successful"
End Sub
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2 comments
Click here for commentsYou are the best! It worked perfectly.
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