WPF 实现拖动工具箱效果

1.效果

  点击左边的矩形拖动到右边canvas面板，右边面板添加矩形

 2.布局

 左边是个StockPanel，上面有个矩形，右边是个Canvas面板。

 矩形是源，Canvas面板是目的，AllowDrop属性都要设成true，矩形框要有填充色，Canvas要有background，否则无法响应鼠标拖拽事件。

 3.矩形框点击事件

 private void rectangle1_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)

        {

            Rectangle rect = sender as Rectangle;

            //创建新矩形

            Rectangle temp = new Rectangle();

            temp.Width = rect.Width;

            temp.Height = rect.Height;

            temp.Fill = rect.Fill;

            temp.Stroke = rect.Stroke;

            //添加移动事件

            temp.MouseLeftButtonDown += new MouseButtonEventHandler(module_MouseLeftButtonDown);

            temp.MouseMove += new MouseEventHandler(module_MouseMove);

            temp.MouseLeftButtonUp += new MouseButtonEventHandler(module_MouseLeftButtonUp);

            DragDrop.DoDragDrop(temp, temp, DragDropEffects.Copy);

        }

 4.Canvas响应事件

private void canvas1_Drop(object sender, DragEventArgs e)

        {

            Rectangle r = (Rectangle)e.Data.GetData(typeof(Rectangle));

            Point p = e.GetPosition(canvas1);

            r.SetValue(Canvas.TopProperty, p.Y-r.Height/2);

            r.SetValue(Canvas.LeftProperty, p.X-r.Width/2);

            canvas1.Children.Add(r);

        }

5.Canvas内的矩形拖动

void module_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)

        {

            Rectangle rect = sender as Rectangle;

            mouseposition = e.GetPosition(canvas1);

            mousedown = true;

            rect.CaptureMouse();

        }

        void module_MouseMove(object sender, MouseEventArgs e)

        {

            Rectangle rect = sender as Rectangle;

            if (mousedown) {

                double deltav = e.GetPosition(canvas1).Y - mouseposition.Y;

                double deltah = e.GetPosition(canvas1).X - mouseposition.X;

                double newtop = deltav + (double)rect.GetValue(Canvas.TopProperty);

                double newleft = deltah + (double)rect.GetValue(Canvas.LeftProperty);

                rect.SetValue(Canvas.TopProperty, newtop);

                rect.SetValue(Canvas.LeftProperty, newleft);

                mouseposition = e.GetPosition(canvas1);

            }

        }

        void module_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)

        {

            Rectangle rect = sender as Rectangle;

            mousedown = false;

            rect.ReleaseMouseCapture();

            mouseposition.X = mouseposition.Y = 0;

        }