private void btnMove_MouseMove(object sender, MouseEventArgs e)
{
if (_mouseDown && !Moving)
{
this.BringToFront();
_relativeToScreen = this.Top - this.PointToScreen(new Point(e.X, e.Y)).Y;
Moving = true;
_moveStarted = true;
}
if (Moving)
{
Point newLoc = new Point(this.Left, this.PointToScreen(new Point(e.X, e.Y)).Y + _relativeToScreen);
EventHandler <LocationChangingEventArgs> locationChanging = LocationChanging;
LocationChangingEventArgs locationArgs = new LocationChangingEventArgs(newLoc);
if (locationChanging != null)
{
locationChanging(this, locationArgs);
}
this.Top = locationArgs.NewLocation.Y;
}
}
private void ControlLocationChanging(object sender, LocationChangingEventArgs e)
{
Control movingControl = sender as Control;
if (movingControl == null)
{
return;
}
if (e.NewLocation.Y - movingControl.Margin.Top < 0)
{
e.NewLocation = new Point(e.NewLocation.X, movingControl.Margin.Top);
}
else if (e.NewLocation.Y + movingControl.Height + movingControl.Margin.Bottom > btnAdd.Top - btnAdd.Margin.Top)
{
e.NewLocation = new Point(e.NewLocation.X, btnAdd.Top - btnAdd.Margin.Top - movingControl.Height - movingControl.Margin.Bottom);
}
if (Panel.Height <= this.Height)
{
return;
}
int viewDelta = -Panel.Location.Y - e.NewLocation.Y;
if (e.NewLocation.Y < -Panel.Location.Y)
{
AutoScrollPosition = new Point(_autoScrollPosition.X, e.NewLocation.Y + viewDelta);
}
}
