SL4.鼠标拖动

利用鼠标响应事件，定位对象的坐标，以实现拖放功能

XAML:

             <Canvas Background="Yellow"  Height="195" Name="canvas1" Width="457">
                <Ellipse MouseMove="ellipse1_MouseMove" MouseLeftButtonDown="ellipse1_MouseLeftButtonDown" 
                         MouseLeftButtonUp="ellipse1_MouseLeftButtonUp" Fill="Gold"  Canvas.Left="118" Canvas.Top="59" Height="100" Name="ellipse1" Stroke="Black" StrokeThickness="3" Width="200" />
            </Canvas>
            <TextBlock Height="23" Name="tbkPoint" Text="" Width="319" />

　　

XAML.CS:

        Point curPos;
        bool mouseMoviing = false;
        private void ellipse1_MouseMove(object sender, MouseEventArgs e)
        {
            FrameworkElement element = sender as FrameworkElement;
            if(mouseMoviing)
            {
                double currX = e.GetPosition(null).X - curPos.X;
                double currY = e.GetPosition(null).Y - curPos.Y;
                element.SetValue(Canvas.TopProperty, currY + (double)element.GetValue(Canvas.TopProperty));
                element.SetValue(Canvas.LeftProperty,
                    currX + (double)element.GetValue(Canvas.LeftProperty));
                tbkPoint.Text = "Ellipse 当前坐标:"+ curPos.X.ToString() + "," + curPos.Y.ToString();
                curPos = e.GetPosition(null);
            }
        }

        private void ellipse1_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            FrameworkElement element = sender as FrameworkElement;
            curPos = e.GetPosition(null);
            mouseMoviing = true;
            if(null!=element)
            {
                element.CaptureMouse();
                element.Cursor = Cursors.Hand;
            }
        }

        private void ellipse1_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            FrameworkElement element = sender as FrameworkElement;
            mouseMoviing = false;
            element.ReleaseMouseCapture();
            curPos.X = 0;
            curPos.Y = 0;
            element.Cursor = null;
        }