WPF 实现拖动工具箱效果

原文: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;

}