<Window x:Class="YourNamespace.YourWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Your Window Title" Height="400" Width="600"
        ResizeMode="NoResize">
    <!-- Window content goes here -->
</Window>

<Window x:Class="YourNamespace.YourWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Your Window Title" Height="400" Width="600"
        Window >
    <!-- Window content goes here -->
</Window>

public partial class YourWindow : Window
{
    private bool isResizing = false;
    private Point resizeStartPoint;
    public YourWindow()
    {
        InitializeComponent();
        MouseDown += Window_MouseDown;
        MouseMove += Window_MouseMove;
        MouseUp += Window_MouseUp;
    }
    private void Window_MouseDown(object sender, MouseButtonEventArgs e)
    {
        if (e.LeftButton == MouseButtonState.Pressed)
        {
            isResizing = true;
            resizeStartPoint = e.GetPosition(this);
        }
    }
    private void Window_MouseMove(object sender, MouseEventArgs e)
    {
        if (isResizing)
        {
            Point currentPoint = e.GetPosition(this);
            double deltaX = currentPoint.X - resizeStartPoint.X;
            double deltaY = currentPoint.Y - resizeStartPoint.Y;
            Width += deltaX;
            Height += deltaY;
        }
    }
    private void Window_MouseUp(object sender, MouseButtonEventArgs e)
    {
        isResizing = false;
    }
}