WPF框选实例代码及程序分享

以下是一个简单的 WPF 框选示例代码和程序的示例，使用 C# 编写。该示例演示如何使用鼠标绘制矩形并选择窗口中的项目。

示例代码：

using System.Windows;

using System.Windows.Controls;

using System.Windows.Input;

using System.Windows.Media;

namespace WpfApplication1

{

public partial class MainWindow : Window

{

private Point startPoint;

private Rectangle rect;

private bool isDragging;

    public MainWindow()
    {
        InitializeComponent();
    }

    private void canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        startPoint = e.GetPosition(canvas);

        rect = new Rectangle
        {
            Stroke = Brushes.LightBlue,
            StrokeThickness = 2,
            Fill = Brushes.Transparent
        };

        Canvas.SetLeft(rect, startPoint.X);
        Canvas.SetTop(rect, startPoint.Y);

        canvas.Children.Add(rect);

        isDragging = true;
    }

    private void canvas_MouseMove(object sender, MouseEventArgs e)
    {
        if (!isDragging)
            return;

        var pos = e.GetPosition(canvas);

        var x = Math.Min(pos.X, startPoint.X);
        var y = Math.Min(pos.Y, startPoint.Y);
        var w = Math.Max(pos.X, startPoint.X) - x;
        var h = Math.Max(pos.Y, startPoint.Y) - y;

        rect.Width = w;
        rect.Height = h;

        Canvas.SetLeft(rect, x);
        Canvas.SetTop(rect, y);
    }

    private void canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        isDragging = false;

        // Perform selection logic here.
    }
}

}