How to use CustomValidator validation control with example in asp.net ~ Asp.Net,C#.Net,VB.Net,MVC,jQuery,JavaScipt,AJAX,WCF,Sql Server example

Introduction: While creating user input form e.g. registration where user inputs the details like Name, email address, password and confirm password ,Website URL,comments/messages etc. we have to implement validations on the form so that incorrect data could not be submitted to server. Asp.net provides Validation controls like CompareValidator, CustomValidator , RangeValidator, RegularExpressionValidator, RequiredFieldValidator etc to apply validations on asp.net web page.

In previous article i explained How to use RequiredFieldValidator validation control with example in asp.net and How to use CompareValidator validation control with example in asp.net and How to use RegularExpressionValidator validation control with example in asp.net and How to use RangeValidator validation control with example in asp.net and JavaScript validation in asp.net website and Jquery form validations in asp.net..
Now in this article I will explain how to use CustomValidator control to check the validity of the comments/message length before submitting to server for processing otherwise error message will be displayed to the user.

CustomValidator vaidation control example in asp.net

When to Use?

When no other validation control provided by visual studio fulfills your validation requirement then CustomValidator can do the job. As the name suggest, CustomValidator can be customized as per application requirement. CustomValidation control can be used to validate the controls client side or server side both.

Note: In our example Message/Comments should be at least 50 character long otherwise validation failure message will appear.

In this example I have demonstrated 3 ways to use CustomValidator control to validate client side and server side.

Client Side Validation using CustomValidator

Case 1: If you want to show the validation failure message near to text box for which the validation failed as shown in figure below:

In the <HEAD> of the design page( .aspx ) tag create a javascript function to validate the Message/comments TextBox length as:

function validateMsgLengthClientSide(sender, args) {

if (args.Value.length < 50)

args.IsValid = false;

else

args.IsValid = true;

}

</script>

then In the <BODY> tag of the design page(.aspx) Place a TextBox controls for entering Message/comments and a Button control for Submitting . Also place a CustomValidator validation controls from validation category from the visual studio toolbox as shown in below:

CustomValidator validation control example in asp.net

<legend>CustomValidator example in asp.net</legend>

<table>

<tr>

<td>Message/Comments <span style="color:red;">*</span></td>

<td>

<asp:TextBox ID="txtMsg" runat="server" TextMode="MultiLine" Rows="2" Columns="35"></asp:TextBox>

</td>

<td>

<asp:CustomValidator ID="csvMsg" runat="server" ErrorMessage="Please enter at least 50 characters message/comment" ControlToValidate="txtMsg" ForeColor="#FF3300" SetFocusOnError="True" ClientValidationFunction="validateMsgLengthClientSide"
ValidateEmptyText="True"> </asp:CustomValidator></td>

</tr>

<tr>

<td>

<asp:Button ID="btnSubmit" runat="server" Text="Submit" />

</td>

<td>

</td>

</tr>

</table>

</fieldset>

Case 2: If you want the validation failure message to show in pop up as shown in figure below:

then change the Display property of the CustomValidator validation controls to None and place a ValidationSummary control from the same validation category from the visual studio toolbox. Set the ShowMessageBox property to true and ShowSummary to false as shown below :

<legend>CustomValidator example in asp.net</legend>

<table>

<tr>

<td>Message/Comments <span style="color:red;">*</span></td>

<td>

<asp:TextBox ID="txtMsg" runat="server" TextMode="MultiLine" Rows="2" Columns="35"></asp:TextBox>

</td>

<td>

<asp:CustomValidator ID="csvMsg" runat="server" ErrorMessage="Please enter at least 50 characters message/comment" ControlToValidate="txtMsg" ForeColor="#FF3300" SetFocusOnError="True" ClientValidationFunction="validateMsgLengthClientSide" Display="Dynamic"
ValidateEmptyText="True"></asp:CustomValidator></td>

</tr>

<tr>

<td>

<asp:Button ID="btnSubmit" runat="server" Text="Submit" />

</td>

<td>

</td>

</tr>

<tr>

<asp:ValidationSummary ID="ValidationSummary1" runat="server" ForeColor="#FF3300" HeaderText="Please correct the following: " ShowMessageBox="True" ShowSummary="False" />

</td>

</tr>

</table>

</fieldset>

Case 3: If you want to show validation failure message in a separate place as shown in figure below :

then Set the ShowMessageBox property to false and ShowSummary property to true as shown below.

<asp:ValidationSummary ID="ValidationSummary1" runat="server" ForeColor="#FF3300" HeaderText="Please correct the following: " ShowMessageBox="False" ShowSummary="True" />

Server Side Validations using CustomValidator

Case 1: If you want to show the validation failure message near to text box for which the validation failed as shown in figure below:

CustomValidator validation control with example in asp.net

<legend>CustomValidator example in asp.net</legend>

<table>

<tr>

<td>Message/Comments <span style="color:red;">*</span></td>

<td>

<asp:TextBox ID="txtMsg" runat="server" TextMode="MultiLine" Rows="2" Columns="35"></asp:TextBox>

</td>

<td>

<asp:CustomValidator ID="csvMsg" runat="server" ErrorMessage="Please enter at least 50 character message/comment" ControlToValidate="txtMsg" ForeColor="#FF3300" SetFocusOnError="True" OnServerValidate="validateMsgLengthServerSide" ValidateEmptyText="True"></asp:CustomValidator>

</td>

</tr>

<tr>

<td>

<asp:Button ID="btnSubmit" runat="server" Text="Submit" />

</td>

<td>

</td>

</tr>

</table>

</fieldset>

Case 2: If you want to show validation failure message in a separate place as shown in figure below :

then Set the ValidationsSummary 's ShowMessageBox property to false and ShowSummary property to true and CustomValidator's Display property to None as shown below

<legend>CustomValidator example in asp.net</legend>

<table>

<tr>

<td>Message/Comments <span style="color:red;">*</span></td>

<td>

<asp:TextBox ID="txtMsg" runat="server" TextMode="MultiLine" Rows="2" Columns="35"></asp:TextBox>

</td>

<td>

</tr>

<tr>

<td>

<asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClick="btnSubmit_Click" />

</td>

<td>

</td>

</tr>

<tr>

<asp:ValidationSummary ID="ValidationSummary1" runat="server" ForeColor="#FF3300" HeaderText="Please correct the following:" ShowMessageBox="false" ShowSummary="true"/>

</td>

</tr>

</table>

</fieldset>

Now over to you:

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8 comments

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Anonymous

admin

August 30, 2013 ×

very informative site :)

Lalit Raghuvanshi

Thanks for your appreciation..stay tuned and stay connected..

September 07, 2013 ×

nice and easy to understand.....

September 08, 2013 ×

keep reading for more useful updates :)

October 15, 2013 ×

thanx

October 16, 2013 ×

Your welcome..stay connected and keep reading :)

Unknown

March 07, 2014 ×

very--- very helpful.....
Big.... Big.... Thanks.....

March 08, 2014 ×

Thanks Lalit Singh..it is always nice to hear that my article helped anyone..Stay connected and keep reading for more useful updates like this one..:)

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How to use CustomValidator validation control with example in asp.net

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