.NET validation in asp.net.

Hi Friend’s , Here I have explained validation in .NET.

Introduction:

Validation controls are hidden controls which are used to validate the data, provided by the user at the client end. As we know that sending a request to the server, it takes lot of time to respond. So it becomes very costly to send all the data entered by the user at the client side, to the server side for the validation. Validation controls work at the client side end only if the browser support JavaScript and some DHTML and can check the date before it sending it to the server.

You can assign more the one validation control to the same data-entry- control, if you want to check multiple conditions at the same time.

There are six type of validation in .NET  which is defined as below:-

1.) Required Field Validator:

This is the simplest control , which is used to ensure that user  has enter the data in data-control or not. Means if user has left blank the field then it will show the error on the page.

You  can add this control by simple drag and drop from the ToolBox control  and simply double click on this control.

When you add RequiredFieldValidation  control on your page , it add the following code on your web page:-

<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="RequiredFieldValidator"></asp:RequiredFieldValidator>

Example:

Validation.aspx:

<asp:TextBox ID="TextBox1" runat="server" style="z-index"></asp:TextBox>

        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="TextBox1" ErrorMessage="This Field cann't be empty."></asp:RequiredFieldValidator>

<asp:Button ID="Button1" runat="server" Text="Submit" />

Run this code . When user click on submit button without filling the field then it will show the error message like ” This field cnn’t be empty.” (You can give any type of error message according to you field.)

2.) RangeValidator Control:

This control is used  to test  if the data entered by the user in a data-entry-control is inside a specified range of values.

Add a RangeValidation Control on your web page by simple drop and drag or doule click on the data-control .

When you add RangeValidationControl  on your page , it add the following code on your web page:-

<asp:RangeValidator ID="RangeValidator1" runat="server" ErrorMessage="RangeValidator"></asp:RangeValidator>

Example:

Validation.aspx:

<asp:TextBox ID="TextBox2" runat="server" style="z-index"></asp:TextBox>

<asp:RangeValidator ID="RangeValidator1" runat="server" ControlToValidate="TextBox2" MinimumValue="18" MaximumValue="60" ErrorMessage="Age should be in the range of 18 to 60."></asp:RangeValidator>

<asp:Button ID="Button1" runat="server" Text="Submit" />

Run this code . When user click on submit button without filling the field then it will show the error message like ” Age should be in the range of 18 to 60.”

3.)RegularExpressionValidator :

This control is used  to test if the data entered by user in a data-entry control matches a pattern defined by regular expression. A regular expression is a string that match a set of string  according to certain syntax  rules.

For example RegularExpression for email  is : \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*

When you add RegularExpressionValidator on your page , it add the following code on your web page:-

<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ErrorMessage="RegularExpressionValidator"></asp:RegularExpressionValidator>

For example

Validation.aspx:

<asp:TextBox ID="TextBox3" runat="server" style="z-index"></asp:TextBox>

<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server"

            ErrorMessage="please enter your mail like sushilct26@gmail.com"

            ControlToValidate="TextBox3"

            ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"></asp:RegularExpressionValidator>

        <asp:Button ID="Button1" runat="server" Text="Submit" />

Run this code . When user click on submit button without filling the field then it will show the error message like ” please enter your mail like sushilct26@gmail.com.”

4.)CompareValidationControl:

This control is used for compare the two data-entry control field .i.e  for password and compare password when user sign up first time .

Add a CompareValidationControl Control on your web page by simple drop and drag or doule click on the data-control .

When you add CompareValidationControl on your page , it add the following code on your web page:-

<asp:CompareValidator ID="CompareValidator1" runat="server" ErrorMessage="CompareValidator"></asp:CompareValidator>

Example:

Validation.aspx:

<asp:TextBox ID="TextBox4" runat="server" style="z-index"></asp:TextBox>

<asp:TextBox ID="TextBox5" runat="server" style="z-index"></asp:TextBox>

<asp:CompareValidator ID="CompareValidator1" runat="server" ControlToValidate="TextBox4" ControlToCompare="TextBox5" ErrorMessage="Type the same password as entered above."></asp:CompareValidator>

        <asp:Button ID="Button1" runat="server" Text="Submit" />

Run this code . When user click on submit button without filling the field then it will show the error message like Type the same password as entered above.”

5.)CustomValidatorControl:

This validation control is  used  to test the data-entry control  data in your own ways. But this validation control has some restriction. You can use this control only for range checking  and comparisons. For example if you want to check whether a number is even or odd then it is not possible for existing validation control. For this type of problem we use CustomeValidation control.

Add a CompareValidationControl Control on your web page by simple drop and drag or doule click on the data-control .

When you add CompareValidationControl on your page , it add the following code on your web page:-

<asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="CustomValidator"></asp:CustomValidator>

Example:

Validation.aspx:

<asp:TextBox ID="TextBox4" runat="server" style="z-index"></asp:TextBox>

<asp:CustomValidator ID="CustomValidator1" runat="server" ControlToValidate="TextBox6" ClientValidationFunction="validation" ErrorMessage="Enter the correct password."></asp:CustomValidator>

        <asp:Button ID="Button1" runat="server" Text="Submit" />

Run this code . When user click on submit button without filling the field then it will show the error message like Enter the correct password.”(This message will pop up when you enter any thing instead  of New York.)

6.) ValidationSummaryControl:

This control is used to display  summary of all error message from all validation control on a web page.

Add a ValidationSummaryControl Control on your web page by simple drop and drag or doule click on the data-control .

When you add ValidationSummaryControl on your page , it add the following code on your web page:-

<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

Example:

Validation.aspx:

<asp:TextBox ID="TextBox1" runat="server" style="z-index"></asp:TextBox>

        <asp:TextBox ID="TextBox2" runat="server" style="z-index"></asp:TextBox>

        <asp:TextBox ID="TextBox3" runat="server" style="z-index"></asp:TextBox>

        <asp:TextBox ID="TextBox4" runat="server" style="z-index"></asp:TextBox>

        <asp:TextBox ID="TextBox5" runat="server" style="z-index"></asp:TextBox>

        <asp:TextBox ID="TextBox6" runat="server" style="z-index"></asp:TextBox>

        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="TextBox1" ErrorMessage="This Field cann't be empty."></asp:RequiredFieldValidator>

        <asp:RangeValidator ID="RangeValidator1" runat="server" ControlToValidate="TextBox2" MinimumValue="18" MaximumValue="60" ErrorMessage="Age should be in the range of 18 to 60."></asp:RangeValidator>

        <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server"

            ErrorMessage="please enter your mail like sushilct26@gmail.com"

            ControlToValidate="TextBox3"

            ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"></asp:RegularExpressionValidator>

        <asp:CompareValidator ID="CompareValidator1" runat="server" ControlToValidate="TextBox4" ControlToCompare="TextBox5" ErrorMessage="Type the same password as entered above."></asp:CompareValidator>

        <asp:CustomValidator ID="CustomValidator1" runat="server" ControlToValidate="TextBox6" ClientValidationFunction="validation" ErrorMessage="Enter the correct password."></asp:CustomValidator>

        <asp:ValidationSummary ID="ValidationSummary1" runat="server" />

        <asp:Button ID="Button1" runat="server" Text="Submit" />

Run this code . When user click on submit button without filling the field then it will show the error message  from all validation.

Donn't forget to comment this post.