How to use Validation Controls in Asp.net

Introduction: In this post I try to explain how we can use the Validations Controls in Asp.net.

Description:

Validation is an important part of all application (window/web). Validation is used to validate the data of input controls e.g. in our application we have textbox control for Username, if user not fill/enter the username it will be displayed a message to user “Please Enter Username”. We can use validation for date format, data range etc.

Validation is of two types:

1.       Client side :

For client side validation we mostly use JavaScript and Jquery. It faster than server side Validation. Client side Validation is not secure because it based on browser and user can disable it.

2.       Server side:

Server side validation is secure but slow in process compared to client side validation. Server side validation based on server.

Validation Controls in Asp.net:

1.       CompareValidator:

Compare validation is used to compare the value enter into two textboxes is same or not. E.g. in registration form we validate the value of password and confirm password.

Example:

Drag and drop the two text boxes from Toolbox. After that take Compare Validator control from Toolbox>Validation. Select the CompareValidator control and go to properties (press F4). Here I want to compare book name enter is same or not. See the blow added snapshot:

See the green mark in snapshot. Select the textboxes Id that you want to compare same or not. ErrorMessage to display the Error and in Font to change the error message style.

<table>

    <tr><td>Book Name:</td><td>

        <asp:TextBox ID="txtbook" runat="server"></asp:TextBox>

       </td></tr>

            <tr><td>Confirm Book Name:</td><td>

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

            runat="server" ErrorMessage="Book Name not Match"

            ControlToCompare="txtbook" ControlToValidate="txtconfirm" Font-Bold="True"

            ForeColor="#FF3300"></asp:CompareValidator></td></tr>

        <tr><td></td><td>

            <asp:Button ID="btninsert" runat="server" Text="Save" /></td></tr>

    </table>

See the below added snapshot. If value is not same:

Value same than no error message.

2.       CustomValidator:

When on other validator then we can use CustomValidator control.

Example:

Drag and drop the text boxes from Toolbox. After that take CustomValidator control from Toolbox>Validation. Select the CustomValidator control and go to properties (press F4). Here I want to compare book name enter is same or not. See the blow added snapshot:

Select textbox to validate, errormessage and font(for style). After go to Events>ServerValidate.

<table>

    <tr><td>Phone Number:</td><td>

        <asp:TextBox ID="txtphone" runat="server"></asp:TextBox>

        <asp:CustomValidator ID="CustomValidator1" runat="server"

            ErrorMessage="Enter 10 Digit Atleast"

            onservervalidate="CustomValidator1_ServerValidate"

            ControlToValidate="txtphone" Font-Bold="True" ForeColor="Red"></asp:CustomValidator>

        </td></tr>

    <tr><td></td><td> <asp:Button ID="Button1" runat="server" Text="Save" /></td></tr></table>

On ServerValidate click write this code:

protected void CustomValidator1_ServerValidate(object source, ServerValidateEventArgs e)

    {

        if (e.Value.Length == 10)

        {

            e.IsValid = true;

        }

        else

        {

            e.IsValid = false;

        }

    }

Check the result with error and without error.

3.       RangeValidator:

It check the value enter in textbox between two given values. We can give a range to enter value in Date, Currency, String, Integer and Double.

Example:

Drag and drop a text box from Toolbox. Take a RangeValidator control from Toolbox>Validation. Select the RangeValidator control and go to properties of control (press F4). See the added snapshot and green marks in snapshot.

Select the textbox value id to validate, enter ErrorMessage want to display, Maximum and Minimum value range. Select the Type, fro Date, Currency etc.

<table>

    <tr><td>Date of Birth:</td><td>

        <asp:TextBox ID="textdob" runat="server"></asp:TextBox>

        <asp:RangeValidator ID="RangeValidator1" runat="server"

            ControlToValidate="textdob" ErrorMessage="Please Enter Date of Birth(DD/MM/YYYY)" Font-Bold="True"

            ForeColor="Red" MaximumValue="12/12/2000" MinimumValue="12/12/1940"

            Type="Date"></asp:RangeValidator>

        </td></tr>

    <tr><td></td><td> <asp:Button ID="Button1" runat="server" Text="Save" /></td></tr></table>

See the added snapshot of enter right format and wrong format of (Error Message) Date of Birth.

4.       RegularExpressionValidator:

RegularExpression validation is used to enter a specified pattern in input/text box. E.g. for enter email etc.

Example:

Drag and drop a text box from Toolbox. Take a RegularExpressionValidator control from Toolbox>Validation. Select the RegularExpressionValidator control and go to properties of control (press F4). See the added snapshot and green marks in snapshot.

Select the textbox want to validate,Errormessage, ValidationExpression(Select the option for which you want to validate e.g. here I select the Internet Email address) and font.

<table>

    <tr><td>Enter Email:</td><td>

        <asp:TextBox ID="txtemail" runat="server" Width="200px"></asp:TextBox>

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

            ErrorMessage="Enter valid Email ID" Font-Bold="True" ForeColor="Red"

            ControlToValidate="txtemail"

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

        </td></tr>

    <tr><td></td><td> <asp:Button ID="Button1" runat="server" Text="Save" /></td></tr></table>

See the result enter full email address and with incomplete information.

5.       RequireFieldValidator:

Requirefield validator control simply validate the data enter in require filed or not.

Example:

Drag and drop a text box from Toolbox. Take a RequireFieldvalidator control from Toolbox>Validation. Select the RequireFieldvalidator control and go to properties of control (press F4). See the added snapshot and green marks in snapshot.

Select the textbox want to validate,Errormessage and font(For style).

<table>

    <tr><td>Book Name:</td><td>

        <asp:TextBox ID="txtbookname" runat="server" Width="200px"></asp:TextBox>

        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"

            ControlToValidate="txtbookname" ErrorMessage="Enter Book Name" Font-Bold="True"

            ForeColor="Red"></asp:RequiredFieldValidator>

        </td></tr>

    <tr><td></td><td> <asp:Button ID="Button1" runat="server" Text="Save" /></td></tr></table>

See the result fill book name and if not enter information.

6.       ValidationSummary:

As the name suggests Validation summary control is used to show validation summary. It shows summary of all validations errors on web page or in a message box.

Example:

Drag and drop a text box from Toolbox. Take a ValidationSummary control from Toolbox>Validation. Select the ValidationSummary control and go to properties of control (press F4). See the added snapshot and green marks in snapshot.

Select the option to show error in MessageBox(true) or ShowSummary(True) and font(For style).

<table>

     <tr><td>Book Name:</td><td>

        <asp:TextBox ID="txtbookname" runat="server" Width="200px"></asp:TextBox>

        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"

            ControlToValidate="txtbookname" ErrorMessage="Enter Book Name" Font-Bold="True"

            ForeColor="Red"></asp:RequiredFieldValidator>

        </td></tr>

                       <tr><td>Book Author:</td><td>

        <asp:TextBox ID="txtauthor" runat="server" Width="200px"></asp:TextBox>

       

                           <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server"

                               ControlToValidate="txtauthor" ErrorMessage="Enter Author Name" Font-Bold="True"

                               ForeColor="Red"></asp:RequiredFieldValidator>

       

        </td></tr>

        <tr><td></td><td>

            <asp:Button ID="btninsert" runat="server" Text="Save"

                onclick="btninsert_Click" />

            <asp:ValidationSummary ID="ValidationSummary1" runat="server" Font-Bold="True"

                ForeColor="Red" ShowMessageBox="True" ShowSummary="False" />

            </td></tr>

    </table>

See the added snapshot for result.

Related Articles on Validation:

Ø  How to Validate Fileupload Control in Asp.netusing Javascript

Ø  How to Validate the Fileupload Control withValidation Control in Asp.net

Ø  How to validate email in asp.net usingJavascript

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