Login

The Login component provides a complete user interface for logging into a web application, including username and password fields, a remember me checkbox, and configurable login button. Original Web Forms documentation is at: https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.webcontrols.login?view=netframework-4.8

Blazor Features Supported

• Username and Password input fields with labels
• Remember Me checkbox (configurable visibility)
• Login button with configurable text and type
• Required field validation for username and password
• Failure text display on authentication failure
• Password recovery, help page, and create user links
• Instruction text display
• OnLoggingIn, OnLoggedIn, OnLoginError, and OnAuthenticate events
• DestinationPageUrl for redirect after successful login
• VisibleWhenLoggedIn to control visibility for authenticated users
• Styling support through cascading style components
• Orientation property (Vertical or Horizontal layout)
• TextLayout property (TextOnLeft or TextOnTop)

WebForms Features Not Supported

• MembershipProvider - use OnAuthenticate event to implement authentication
• FailureAction property
• LayoutTemplate
• RenderOuterTable property

WebForms Syntax

<asp:Login
    CreateUserIconUrl="uri"
    CreateUserText="string"
    CreateUserUrl="uri"
    DestinationPageUrl="uri"
    DisplayRememberMe="True|False"
    FailureText="string"
    HelpPageIconUrl="uri"
    HelpPageText="string"
    HelpPageUrl="uri"
    ID="string"
    InstructionText="string"
    LoginButtonImageUrl="uri"
    LoginButtonText="string"
    LoginButtonType="Button|Image|Link"
    MembershipProvider="string"
    OnAuthenticate="Authenticate event handler"
    OnLoggedIn="LoggedIn event handler"
    OnLoggingIn="LoggingIn event handler"
    OnLoginError="LoginError event handler"
    PasswordLabelText="string"
    PasswordRecoveryIconUrl="uri"
    PasswordRecoveryText="string"
    PasswordRecoveryUrl="uri"
    PasswordRequiredErrorMessage="string"
    RememberMeSet="True|False"
    RememberMeText="string"
    runat="server"
    TitleText="string"
    UserName="string"
    UserNameLabelText="string"
    UserNameRequiredErrorMessage="string"
    VisibleWhenLoggedIn="True|False"
/>

Blazor Syntax

<Login TitleText="Sign In"
       UserNameLabelText="Email:"
       PasswordLabelText="Password:"
       LoginButtonText="Sign In"
       OnAuthenticate="HandleAuthenticate"
       OnLoggedIn="HandleLoggedIn"
       DestinationPageUrl="/dashboard">
    <TitleTextStyle ForeColor="Navy" Font-Bold="true" />
    <LoginButtonStyle BackColor="Blue" ForeColor="White" />
</Login>

@code {
    private void HandleAuthenticate(AuthenticateEventArgs args)
    {
        // Implement your authentication logic here
        args.Authenticated = ValidateCredentials(args);
    }

    private void HandleLoggedIn(EventArgs args)
    {
        // Handle successful login
    }
}

Usage Notes

The Login component requires integration with Blazor's AuthenticationStateProvider for authentication state management.

Authentication Flow

1. User enters credentials and clicks login button
2. OnLoggingIn event fires (can be cancelled)
3. OnAuthenticate event fires - you must set args.Authenticated = true if credentials are valid
4. If authenticated, OnLoggedIn fires and user is redirected to DestinationPageUrl
5. If not authenticated, OnLoginError fires and FailureText is displayed

Example with Custom Authentication

<Login OnAuthenticate="HandleAuthenticate"
       OnLoggedIn="HandleLoggedIn"
       OnLoginError="HandleLoginError"
       DestinationPageUrl="/home">
</Login>

@code {
    private async Task HandleAuthenticate(AuthenticateEventArgs args)
    {
        // Your authentication logic
        var result = await AuthService.ValidateAsync(userName, password);
        args.Authenticated = result.Success;
    }
}

Styling

The Login component supports child style components for customization:

Style Component	Description
TitleTextStyle	Styles the title text
LabelStyle	Styles the username and password labels
TextBoxStyle	Styles the input text boxes
CheckBoxStyle	Styles the remember me checkbox
LoginButtonStyle	Styles the login button
FailureTextStyle	Styles the failure message
HyperLinkStyle	Styles the help and recovery links
InstructionTextStyle	Styles the instruction text
ValidatorTextStyle	Styles validation error messages

Orientation and TextLayout

The Login component supports two layout properties that control how the form is arranged:

Orientation controls whether fields are stacked vertically or arranged side by side:

Value	Description
Orientation.Vertical	Fields stacked vertically (default)
Orientation.Horizontal	Fields arranged side by side

TextLayout controls label placement relative to input fields:

Value	Description
LoginTextLayout.TextOnLeft	Labels appear to the left of inputs (default)
LoginTextLayout.TextOnTop	Labels appear above inputs

@using BlazorWebFormsComponents.Enums

<Login TitleText="Sign In"
       Orientation="Orientation.Horizontal"
       TextLayout="LoginTextLayout.TextOnTop"
       InstructionText="Enter your credentials." />

Migration Example

Before (Web Forms):

<asp:Login ID="Login1" runat="server"
    TitleText="Sign In"
    Orientation="Horizontal"
    TextLayout="TextOnTop"
    OnAuthenticate="Login1_Authenticate">
    <TitleTextStyle ForeColor="Navy" Font-Bold="True" />
    <LoginButtonStyle BackColor="Blue" ForeColor="White" />
</asp:Login>

After (Blazor):

<Login TitleText="Sign In"
       Orientation="Orientation.Horizontal"
       TextLayout="LoginTextLayout.TextOnTop"
       OnAuthenticate="HandleAuthenticate">
    <TitleTextStyle ForeColor="Navy" Font-Bold="true" />
    <LoginButtonStyle BackColor="Blue" ForeColor="White" />
</Login>