protected override void OnDragOver(DragEventArgs drgevent)
{
MyFlowPanel dst = this;
Point p = dst.PointToClient(new Point(drgevent.X, drgevent.Y));
Control item = dst.GetChildAtPoint(p);
if (item == null) // move the point a bit to the left, if the cursor is between two buttons
{
p.X -= 6;
item = dst.GetChildAtPoint(p);
}
if (item != null)
{
int currentIndex = dst.Controls.GetChildIndex(item, false);
Point pRelativeToControl = item.PointToClient(new Point(drgevent.X, drgevent.Y));
double xInPercent = pRelativeToControl.X / (double)item.Width * 100.0;
bool isLastItem = false;
if (xInPercent > 50.0)
{
if (++currentIndex >= dst.Controls.Count)
{
item = dst.Controls[dst.Controls.Count - 1];
isLastItem = true;
}
else
{
item = dst.Controls[currentIndex];
}
}
if (item != null && (dragInsertIndex == -1 || currentIndex != dragInsertIndex))
{
using (Graphics g = CreateGraphics())
{
g.Clear(this.BackColor);
dragInsertIndex = currentIndex;
int xPos = item.Location.X - 3;
if (isLastItem)
{
xPos = item.Location.X + item.Width + 1;
}
g.FillRectangle(Brushes.CornflowerBlue, xPos, 2, 2, item.Height);
}
}
}
base.OnDragOver(drgevent);
}
protected override void OnDragDrop(DragEventArgs drgevent)
{
CustomButtonIB btn = (CustomButtonIB)drgevent.Data.GetData(typeof(CustomButtonIB));
MyFlowPanel dst = this;
MyFlowPanel src = btn?.Parent as MyFlowPanel;
if (btn != null && src != null && dst != null && src == dst)
{
drgevent.Effect = DragDropEffects.Move;
int oldindex = dst.Controls.GetChildIndex(btn);
OrderChanged?.Invoke(oldindex, dragInsertIndex);
dragInsertIndex = -1;
}
else
{
drgevent.Effect = DragDropEffects.None;
dragInsertIndex = -1;
}
base.OnDragDrop(drgevent);
}
protected override void OnDragDrop(DragEventArgs drgevent)
{
CustomButtonIB btn = (CustomButtonIB)drgevent.Data.GetData(typeof(CustomButtonIB));
MyFlowPanel dst = this;
MyFlowPanel src = btn?.Parent as MyFlowPanel;
if (btn != null && src != null && dst != null && src == dst)
{
drgevent.Effect = DragDropEffects.Move;
Point p = dst.PointToClient(new Point(drgevent.X, drgevent.Y));
Control item = dst.GetChildAtPoint(p);
int oldindex = dst.Controls.GetChildIndex(btn);
int newindex = dst.Controls.GetChildIndex(item, false);
OrderChanged?.Invoke(oldindex, newindex);
}
else
{
drgevent.Effect = DragDropEffects.None;
}
base.OnDragDrop(drgevent);
}
