Display a Password Entry Box and get the input

   
  

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="WPF" Height="100" Width="300">
    <StackPanel Orientation="Horizontal">
        <TextBlock Margin="5" VerticalAlignment="Center">
            Enter Password:
        </TextBlock>
        <PasswordBox Name="passwordBox" PasswordChar="!" 
                     VerticalAlignment="Center" Width="150" />
        <Button Content="OK" IsDefault="True" Margin="5" Name="button1" 
                VerticalAlignment="Center" Click="button1_Click" />
    </StackPanel>
</Window>
//File:Window.xaml.cs
using System.Windows;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, RoutedEventArgs e)
        {
            MessageBox.Show("Password entered: " + passwordBox.Password,Title);
        }
    }
}