PasswordBox Control

The PasswordBox control is used to securely accept and display user-entered passwords.

Introduction

The PasswordBox control is a specialized version of the TextBox control that masks the characters entered by the user with placeholder characters (e.g., dots or asterisks) to prevent unauthorized viewing of sensitive information. This is crucial for implementing secure login forms and other scenarios where password input is required.

Basic Usage

To use a PasswordBox, you simply declare it in your XAML or create it programmatically.

XAML Example:

<Page
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <Grid Padding="20">
        <StackPanel Spacing="10">
            <TextBlock Text="Enter your password:" Style="{StaticResource SubheaderTextBlockStyle}"/>
            <PasswordBox Width="300" PasswordChar="●"/>
        </StackPanel>
    </Grid>
</Page>

C# Code Example:

using Microsoft.UI.Xaml.Controls;

            // ... inside a Page or UserControl

            var passwordBox = new PasswordBox();
            passwordBox.PasswordChar = '•'; // Using a different character for demonstration
            passwordBox.Width = 300;

            // Add to your visual tree (e.g., a Grid)
            MyGrid.Children.Add(passwordBox);

Key Properties

The PasswordBox control offers several properties to customize its behavior and appearance:

Password Management

While the PasswordBox masks input, it's important to handle the password securely when retrieving it.

Retrieving the Password:

You can access the actual password using the Password property. This should typically be done in response to an event, such as a button click for submission.

// In your code-behind (e.g., C#)
                private void LoginButton_Click(object sender, RoutedEventArgs e)
                {
                    string enteredPassword = MyPasswordBox.Password;

                    if (!string.IsNullOrEmpty(enteredPassword))
                    {
                        // TODO: Implement secure password validation and authentication logic here
                        // Avoid displaying or logging the password directly.
                        System.Diagnostics.Debug.WriteLine($"Password entered (for demo purposes only): {enteredPassword}");
                        MyPasswordBox.Password = ""; // Clear the password after processing
                    }
                    else
                    {
                        // Show an error message to the user
                        var dialog = new ContentDialog()
                        {
                            Title = "Login Error",
                            Content = "Please enter your password.",
                            CloseButtonText = "Ok",
                            XamlRoot = this.Content.XamlRoot
                        };
                        await dialog.ShowAsync();
                    }
                }

Password Masking Characters

You can change the character used for masking by setting the PasswordChar property. Common choices include:

• '●' (default)
• '*'
• '•'

Customization and Styling

The PasswordBox control can be extensively customized using styles and templates to match your application's design. You can modify its appearance, add watermarks, and integrate it seamlessly into your UI.

Example: Styling a PasswordBox

<Page.Resources>
                <Style TargetType="PasswordBox" x:Key="CustomPasswordBoxStyle">
                    <Setter Property="FontSize" Value="16"/>
                    <Setter Property="Padding" Value="10"/>
                    <Setter Property="BorderBrush" Value="DarkGray"/>
                    <Setter Property="BorderThickness" Value="1"/>
                    <Setter Property="CornerRadius" Value="5"/>
                    <Setter Property="Background" Value="WhiteSmoke"/>
                    <Setter Property="Foreground" Value="#333"/>
                    <Setter Property="PasswordChar" Value="*"/>
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="PasswordBox">
                                <Grid Background="{TemplateBinding Background}"
                                      BorderBrush="{TemplateBinding BorderBrush}"
                                      BorderThickness="{TemplateBinding BorderThickness}"
                                      CornerRadius="{TemplateBinding CornerRadius}">
                                    <ScrollViewer x:Name="ContentElement"
                                                  Padding="{TemplateBinding Padding}"
                                                  HorizontalScrollBarVisibility="Hidden"
                                                  VerticalScrollBarVisibility="Hidden"
                                                  ZoomMode="Disabled"/>
                                </Grid>
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </Style>
            </Page.Resources>

            <PasswordBox Style="{StaticResource CustomPasswordBoxStyle}" Width="300"/>

Namespaces

The PasswordBox control is part of the following namespaces:

• Core: Microsoft.UI.Xaml.Controls
• Foundation: Windows.UI.Xaml

See Also

• TextBox Control
• Input Validation in WinUI
• Control Templating