Simulating a Drag/Drop event in WPF - wpf

Question

I want to simulate a drag/drop event in WPF.
For this I'll need to gain access to the data stored in the "Drag/Drop buffer" and also I'll need to create a DragEventArgs.
I noticed that the DragEventArgs is sealed and has no public ctor.
So my questions are:
1. how can I create an instance of DragEventArgs?
2. How can I gain access to the drag/drop buffer?

Answer 1

i recently do this! i simulated drag/drop with MouseDown, MouseMove and MouseUp events. for example for my application, i have some canvases that i want to drag and drop them. every canvas has an id. in MouseDown event, i buffer its id and use it in MouseMove and MouseUp event. Desktop_Canvas is my main Canvas that contains some canvases. these canvases are in my dictionary (dic).
here is my code:
private Dictionary<int, Win> dic = new Dictionary<int, Win>();
private Point downPoint_Drag = new Point(-1, -1);
private int id_Drag = -1;
private bool flag_Drag = false;
public class Win
{
public Canvas canvas = new Canvas();
public Point downpoint = new Point();
public Win()
{
canvas.Background = new SolidColorBrush(Colors.Gray);
}
}
private void Desktop_Canvas_MouseMove(object sender, MouseEventArgs e)
{
try
{
Point movePoint = e.GetPosition(Desktop_Canvas);
if (flag_Drag && downPoint_Drag != new Point(-1, -1))
{
double dy1 = movePoint.Y - downPoint_Drag.Y, x = -1, dx1 = movePoint.X - downPoint_Drag.X, y = -1;
downPoint_Drag = movePoint;
if (x == -1)
x = Canvas.GetLeft(dic[id_Drag].canvas) + dx1;
if (y == -1)
y = Canvas.GetTop(dic[id_Drag].canvas) + dy1;
Canvas.SetLeft(dic[id_Drag].canvas, x);
Canvas.SetTop(dic[id_Drag].canvas, y);
}
}
catch
{
MouseEventArgs ee = new MouseEventArgs((MouseDevice)e.Device, 10);
Desktop_Canvas_MouseLeave(null, ee);
}
}
private void Desktop_Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
try
{
downPoint_Drag = new Point(-1, -1);
id_Drag =-1;
flag_Drag = false;
}
catch
{
MouseEventArgs ee = new MouseEventArgs((MouseDevice)e.Device, 10);
Desktop_Canvas_MouseLeave(null, ee);
}
}
private void Desktop_Canvas_MouseLeave(object sender, MouseEventArgs e)
{
MouseButtonEventArgs ee = new MouseButtonEventArgs((MouseDevice)e.Device, 10, MouseButton.Left);
Desktop_Canvas_MouseLeftButtonUp(null, ee);
}
void canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
downPoint_Drag = e.GetPosition(Desktop_Canvas);
int hoverId = HoverWin(downPoint_Drag);
flag_Drag = true;
id_Drag = hoverId;
dic[id_Drag].downpoint = new Point(downPoint_Drag.X, downPoint_Drag.Y);
}
private int HoverWin(Point p)
{
foreach (int i in dic.Keys)
{
if (dic[i].canvas.IsMouseOver)
return i;
}
return -1;
}