<Window x:Class="LineDrawingApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Line Drawing App" Width="800" Height="600">
    <Grid>
        <Canvas Name="canvas" Background="White"
                MouseLeftButtonDown="canvas_MouseLeftButtonDown"
                MouseLeftButtonUp="canvas_MouseLeftButtonUp"
                MouseMove="canvas_MouseMove"/>
        <Button Name="btnDrawLine" Content="Draw Line" HorizontalAlignment="Left" VerticalAlignment="Bottom" Width="100" Click="btnDrawLine_Click"/>
    </Grid>
</Window>