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I can't understand why it is.

Here is some code of mine:

This is the overridden OnMouseMove method for the customized Label (my arrow):

```
protected override void OnMouseMove(MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
//Check if mouse holds down on the middle of the arrow then just move it or translate it, not rotate.
if (downPoint == MouseDownPoint.Middle)
{
Left += e.X - oldPos.X;
Top += e.Y - oldPos.Y;
}
else //if mouse holds down on one of the two heads of the arrow then start rotating.
{
if (downPoint == MouseDownPoint.First)
{
if (a != ArrowType.LastToFirst)
TurnTailPointTo(Parent.PointToClient(PointToScreen(e.Location)));
else TurnHeadPointTo(Parent.PointToClient(PointToScreen(e.Location)));
}
else if (a != ArrowType.LastToFirst)
TurnHeadPointTo(Parent.PointToClient(PointToScreen(e.Location)));
else TurnTailPointTo(Parent.PointToClient(PointToScreen(e.Location)));
}
Invalidate();
first = Parent.PointToClient(PointToScreen(localFirst));
last = Parent.PointToClient(PointToScreen(localLast));
}
base.OnMouseMove(e);
}
```

Here are the code for

```
void TurnPointTo(Point Tip, Point p)
{
if (Parent != null) Parent.SuspendLayout();
Size = new Size(2 * Math.Abs(Tip.X - p.X) + 10 + fontHeight, 2 * Math.Abs(Tip.Y - p.Y) + 10 + fontHeight);
turning = true;
Location = new Point(Math.Min(p.X, Tip.X) - Width / 2, Math.Min(p.Y, Tip.Y) - Height / 2);
turning = false;
if (Parent != null) Parent.ResumeLayout();
}
public void TurnHeadPointTo(Point p)
{
if (a != ArrowType.LastToFirst)
{
TurnPointTo(first, p);
localLast = new Point(p.X - Location.X, p.Y - Location.Y);
localFirst = new Point(first.X - Location.X, first.Y - Location.Y);
last = p;
}
else
{
TurnPointTo(last, p);
localFirst = new Point(p.X - Location.X, p.Y - Location.Y);
localLast = new Point(last.X - Location.X, last.Y - Location.Y);
first = p;
}
Invalidate();
}
public void TurnTailPointTo(Point p)
{
if (a != ArrowType.LastToFirst)
{
TurnPointTo(last, p);
localLast = new Point(last.X - Location.X, last.Y - Location.Y);
localFirst = new Point(p.X - Location.X, p.Y - Location.Y);
first = p;
}
else
{
TurnPointTo(first, p);
localLast = new Point(p.X - Location.X, p.Y - Location.Y);
localFirst = new Point(first.X - Location.X, first.Y - Location.Y);
last = p;
}
Invalidate();
}
```

My idea is each time the rotating action happens, I will resize the customized label to the new size which can contain the 2 points of 2 heads of the arrow, and relocate it, update the

Here is the code for the OnPaint method of the customized Label:

```
protected override void OnPaint(PaintEventArgs e)
{
GraphicsPath gp = new GraphicsPath();
Point tail = a == ArrowType.FirstToLast || a == ArrowType.None ?
```**localFirst** : **localLast**;
Point head = a == ArrowType.FirstToLast || a == ArrowType.None ? **localLast** : **localFirst**;
int h = Math.Max(tail.Y, head.Y) - Math.Min(tail.Y, head.Y);
int w = Math.Max(tail.X, head.X) - Math.Min(tail.X, head.X);
float alpha = (float)Math.Atan((float)h / w);
int dx = (int)((thick / 2) * Math.Sin(alpha));
int dy = (int)((thick / 2) * Math.Cos(alpha));
int signDx = 1, signDy = 1, signHeadX = 1, signHeadY = 1;
if (tail.X >= head.X && tail.Y >= head.Y)
{
signDx = -1;
}
else if (tail.X <= head.X && tail.Y <= head.Y)
{
signDy = -1;
signHeadX = signHeadY = -1;
}
else if (tail.Y >= head.Y)
{
signDx = signDy = -1;
signHeadX = -1;
}
else
{
signHeadY = -1;
}
Point p1 = new Point(tail.X + signDx * dx, tail.Y + signDy * dy);
Point p2 = new Point(tail.X - signDx * dx, tail.Y - signDy * dy);
Point p3 = new Point(head.X + signDx * dx, head.Y + signDy * dy);
Point p4 = new Point(head.X - signDx * dx, head.Y - signDy * dy);
if (a == ArrowType.None)//Just shape a line
{
gp.AddLines(new Point[] { p1, p2, p4, p3 });
}
else//Shape an arrow
{
Point k = new Point((int)(head.X + signHeadX * 10 * Math.Cos(alpha)), (int)(head.Y + signHeadY * 10 * Math.Sin(alpha)));
p3 = new Point(k.X + signDx * dx, k.Y + signDy * dy);
p4 = new Point(k.X - signDx * dx, k.Y - signDy * dy);
k = new Point((int)Math.Round((head.X + signHeadX * 20 * Math.Cos(alpha))), (int)Math.Round((head.Y + signHeadY * 20 * Math.Sin(alpha))));
dx = (int)(2 * thick * Math.Sin(alpha));
dy = (int)(2 * thick * Math.Cos(alpha));
Point p5 = new Point(k.X + signDx * dx, k.Y + signDy * dy);
Point p6 = new Point(k.X - signDx * dx, k.Y - signDy * dy);
gp.AddLines(new Point[] { p1, p2, p4, p6, head, p5, p3 });
}
gp.AddPath(val, true);
Region = new Region(gp);
base.OnPaint(e);
}

Please don't suggest me the idea using

I also tried overriding CreateParams of the form and add the ExStyle with 0x02000000 as many other sites discussed about preventing flicker. I think my problem is some kind of flicker.

Hope you understand my idea as well as my code to help me out!

Your help would be highly appreciated! Thanks!

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