WPF and XAML Basics

C# in Visual Studio 2026 — a hands-on guide for developers at every level.

What is WPF?

Windows Presentation Foundation (WPF) is a modern desktop UI framework using XAML (Extensible Application Markup Language) for layouts and data binding for connecting UI to data. WPF supports GPU-accelerated rendering, styles, templates, and animations.

Creating a WPF Project

1. File → New → Project → WPF Application.
2. Select .NET 9 target framework.

XAML Basics

<!-- MainWindow.xaml -->
<Window x:Class="MyApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="WPF Demo" Width="400" Height="250">

  <StackPanel Margin="16">
    <TextBlock Text="Enter your name:" Margin="0 0 0 8"/>
    <TextBox x:Name="txtName" Margin="0 0 0 8"/>
    <Button Content="Greet" Click="BtnGreet_Click"/>
    <TextBlock x:Name="lblOutput" FontSize="18" Margin="0 12 0 0"/>
  </StackPanel>

</Window>

Code-Behind

// MainWindow.xaml.cs
private void BtnGreet_Click(object sender, RoutedEventArgs e)
    => lblOutput.Text = $"Hello, {txtName.Text}!";

Data Binding

// ViewModel
public class MainViewModel : INotifyPropertyChanged
{
    private string _name = "";
    public string Name
    {
        get => _name;
        set { _name = value; OnPropertyChanged(); }
    }
    public event PropertyChangedEventHandler? PropertyChanged;
    protected void OnPropertyChanged([CallerMemberName] string? n = null)
        => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(n));
}