public partial class Page : UserControl
{
bool isDragDropInEffect = false;
Point pos;
public Page()
{
InitializeComponent();
// Loop through all the UIElements in the Canvas
// and attach Mouse Event Handlers to the Element
foreach (UIElement uiEle in CanvasParent.Children)
{
uiEle.MouseMove += new MouseEventHandler(Element_MouseMove);
uiEle.MouseLeftButtonDown += new MouseButtonEventHandler(Element_MouseLeftButtonDown);
uiEle.MouseLeftButtonUp += new MouseButtonEventHandler(Element_MouseLeftButtonUp);
}
}
void Element_MouseMove(object sender, MouseEventArgs e)
{
if (isDragDropInEffect)
{
FrameworkElement currEle = sender as FrameworkElement;
// Retrieving the item's current x and y position
double xPos = e.GetPosition(null).X - pos.X;
double yPos = e.GetPosition(null).Y - pos.Y;
// Re-position Element
currEle.SetValue(Canvas.TopProperty, yPos + (double)currEle.GetValue(Canvas.TopProperty));
currEle.SetValue(Canvas.LeftProperty, xPos + (double)currEle.GetValue(Canvas.LeftProperty));
// Reset the new position value
pos = e.GetPosition(null);
}
}
void Element_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
FrameworkElement fEle = sender as FrameworkElement;
isDragDropInEffect = true;
// x and y coords of mouse pointer position
pos = e.GetPosition(null);
// Enable mouse capture on element
fEle.CaptureMouse();
// Set the cursor to 'Hand' when mouse pointer is over element
fEle.Cursor = Cursors.Hand;
}
void Element_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
if (isDragDropInEffect)
{
FrameworkElement ele = sender as FrameworkElement;
isDragDropInEffect = false;
// Removes Mouse Capture from Element being dragged
ele.ReleaseMouseCapture();
}
}
}
这段代码把CanvasContent里的元素都变成可拖拽的.