Unit 02

GridView is an ASP.NET server control used to display data from a data source in a tabular format. It is commonly used to display records retrieved from databases.

Features of GridView

Example

<asp:GridView ID="GridView1"
    runat="server"
    AutoGenerateColumns="true">
</asp:GridView>

RequiredFieldValidator is an ASP.NET validation control used to ensure that a specified input field is not left empty. It checks whether the user has entered a value before the form is submitted.

Important Properties

Example

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

<asp:RequiredFieldValidator
    ID="rfvName"
    runat="server"
    ControlToValidate="txtName"
    ErrorMessage="Name is required." />

AutoPostBack is a property of ASP.NET server controls that determines whether a control should automatically submit the page back to the server when its value changes.

When AutoPostBack="true", the control immediately causes a postback when the relevant event occurs.

Example

<asp:DropDownList ID="ddlCity"
    runat="server"
    AutoPostBack="true"
    OnSelectedIndexChanged="ddlCity_SelectedIndexChanged">
    <asp:ListItem>Ahmedabad</asp:ListItem>
    <asp:ListItem>Surat</asp:ListItem>
</asp:DropDownList>

Code-behind:

protected void ddlCity_SelectedIndexChanged(
    object sender, EventArgs e)
{
    // Code executes automatically after selection changes
}

Here, when the user selects a different city, the page automatically posts back to the server and the SelectedIndexChanged event is executed.

Web.config is an XML configuration file used in ASP.NET applications to store and manage application-level settings and configuration information.

Importance of Web.config

• 01Stores database connection strings.
• 02Configures authentication and authorization.
• 03Controls session state and application settings.
• 04Helps configure custom error handling.
• 05Allows application settings to be changed without modifying the source code.

Example

<configuration>
    <appSettings>
        <add key="SiteName" value="My Website"/>
    </appSettings>
</configuration>

The Login Control in ASP.NET is a ready-made server control used to provide a username and password login interface. It integrates with the ASP.NET Membership Provider, so developers do not need to create the complete login form manually.

Important Properties

• 01UserName — Gets or sets the username entered by the user.
• 02Password — Gets or sets the password entered by the user.
• 03RememberMeSet — Determines whether the user's login should be remembered.
• 04RememberMeText — Specifies the text displayed for the Remember Me option.
• 05DestinationPageUrl — Specifies the page to which the user is redirected after successful login.
• 06FailureText — Specifies the message displayed when login authentication fails.

Example

<asp:Login ID="loginCtrl" runat="server"
    DestinationPageUrl="~/Dashboard.aspx"
    FailureText="Invalid username or password. Try again." />

This creates a login form with username, password, and Remember Me functionality. If authentication is successful, the user is redirected to Dashboard.aspx; otherwise, the specified failure message is displayed.

Other ASP.NET Login Controls

Validation is the process of checking whether the data entered by the user is correct and follows the required rules. ASP.NET supports both client-side and server-side validation.

Example

ASP.NET validation controls can perform client-side validation using JavaScript and also perform server-side validation. Server-side validation should always be used for security because client-side validation can be bypassed.

<asp:RequiredFieldValidator
    ID="rfvName"
    runat="server"
    ControlToValidate="txtName"
    ErrorMessage="Name is required." />

Validation Controls are ASP.NET server controls used to validate user input before the form is submitted or processed. They help ensure that the data entered by the user is correct and meets the required conditions.

Types of Validation Controls

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

<asp:RequiredFieldValidator
    ID="rfvName"
    runat="server"
    ControlToValidate="txtName"
    ErrorMessage="Name is required." />

<asp:CompareValidator
    ID="cvPassword"
    runat="server"
    ControlToValidate="txtConfirm"
    ControlToCompare="txtPassword"
    ErrorMessage="Passwords do not match." />

<asp:RangeValidator
    ID="rvAge"
    runat="server"
    ControlToValidate="txtAge"
    MinimumValue="18"
    MaximumValue="60"
    Type="Integer"
    ErrorMessage="Age must be between 18 and 60." />

<asp:RegularExpressionValidator
    ID="revEmail"
    runat="server"
    ControlToValidate="txtEmail"
    ValidationExpression="^[^@\s]+@[^@\s]+\.[^@\s]+$"
    ErrorMessage="Enter a valid email." />

<asp:CustomValidator
    ID="cvCustom"
    runat="server"
    ControlToValidate="txtCode"
    ErrorMessage="Invalid code."
    OnServerValidate="ValidateCode" />

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

Common Properties