Drawing and out of memory exceptions

Question

Hi

im having some issues with memory.

I have an on paint event:

private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{

float mspeed = 30;

float cspeed = 180/mspeed*float.Parse(this.labSpeed.Text);

e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
using (Pen p = new Pen(Color.Green, 30))
{
e.Graphics.DrawArc(p, 40, 20, 80, 80, 180, 180);
}
using (Pen p = new Pen(Color.Red, 20))
{
//p.Alignment = PenAlignment.Inset;
e.Graphics.DrawArc(p, 40, 20, 80, 80, 180, cspeed);
}
using (Pen p = new Pen(Color.Orange, 10))
{
//p.Alignment = PenAlignment.Inset;
e.Graphics.DrawArc(p, 40, 20, 80, 80, 180, float.Parse(this.labPB.Text)*180/mspeed);
}

}

On my timer I have a this.invalidate() to make sure tis called but am getting out of memory errors. the faster the ticker is going the sooner the error so im guessing theres some kind of memory leak. is there a way to clear this up or release what ever is being used?

I've done lots of searching but it appears this out of memory expection is thrown up for all kinds of errors :/

Box · Answer

Well I did think that at one point which is why I added 1 to the curve so it was atleast 1 at all times. I even tried with 10 but that still errored (at the curve was actually drawn!). and incase the form hadnt loaded fully I turned the ticker off and had it turn on after the form was opened.

Vulpes · Answer

No there's nothing to worry about there but I just did a quick google to see whether this problem had been reported before and found this: http://stackoverflow.com/questions/3665206/why-is-my-c-sharp-paint-method-running-out-of-memory So the culprit may be a bug in the DrawArc method when using small angles though I couldn't really tell from the code how small your sweep angles were.

Box · Answer

private void timer1_Tick(object sender System.EventArgs e) { int x1 = 0; int x2 = 0; int y1 = 0; int y2 = 0; double d = 0; double s = 0; this.labLastX.Text = this.labXPOS.Text; this.labLastY.Text = this.labYPOS.Text; this.labXPOS.Text = System.Windows.Forms.Cursor.Position.X.ToString(); this.labYPOS.Text = System.Windows.Forms.Cursor.Position.Y.ToString(); this.labMouseButton.Text=Control.MouseButtons.ToString(); x1 = int.Parse(this.labLastX.Text); x2 = int.Parse(this.labXPOS.Text); y1 = int.Parse(this.labLastY.Text); y2 = int.Parse(this.labYPOS.Text); d = Math.Round(Math.Sqrt(((x1-x2)*(x1-x2))+((y1-y2)*(y1-y2)))0); this.labTickDistance.Text=d.ToString(); d += int.Parse(this.labSeshDistance.Text); this.labSeshDistance.Text = d.ToString(); d = int.Parse(this.labSeshDistance.Text) + int.Parse(this.labPrevDistance.Text); this.labDistance.Text = Math.Round(d/10000002).ToString() + m; q.Enqueue(d); if (q.Count > 10) { s = (double)q.Dequeue(); } else { s = (double)q.Peek(); } s = d - s; s *= 1800; this.labPPH.Text=Math.Round(s/10000002).ToString() + m; s = Math.Round(s/4561923); this.labSpeed.Text = s.ToString(); if (s > double.Parse(this.labPB.Text)) { this.labPB.Text=s.ToString(); } d = Math.Round(d/45619202); this.labMiles.Text=d.ToString(); this.notifyIcon1.Text=Math.Round(d2).ToString() +  miles; this.Invalidate(); } not that I can see. I am still very new to this though so maybe? Above is my code in the ticker

Vulpes · Answer

It is puzzling but it definitely seems to be related to the timer. Are you creating any objects in the timer_Tick eventhandler that are not being disposed of immediately?

Box · Answer

Vulpes to the rescue again :) I tried the caching method but it still errors out. then I tried taking out the arc. having the green and orange never errors. the red one did though. now it tends to either error right away or its fine for a while (10 mins and counting now) very puzzling -_-

Vulpes · Answer

I can't really see why the code in that Paint handler should cause an out of memory error. The Pen objects are being disposed of as soon as they've been used and you never need to dispose of the Graphics object provided by the PaintEventArgs. You could try caching the Pen objects to relieve some pressure on the garbage collector and see if that makes any difference. If it doesn't then the answer probably lies elsewhere: private Pen greenPen = new Pen(Color.Green 30); private Pen redPen = new Pen(Color.Red 20); private Pen orangePen = new Pen(Color.Orange 10); private void Form1_Paint(object sender System.Windows.Forms.PaintEventArgs e) { float mspeed = 30; float cspeed = 180/mspeed * float.Parse(this.labSpeed.Text); e.Graphics.SmoothingMode = SmoothingMode.AntiAlias; e.Graphics.DrawArc(greenPen 40 20 80 80 180 180); //p.Alignment = PenAlignment.Inset; e.Graphics.DrawArc(redPen 40 20 80 80 180 cspeed); //p.Alignment = PenAlignment.Inset; e.Graphics.DrawArc(orangePen 40 20 80 80 180 float.Parse(this.labPB.Text)*180/mspeed); } private void Form1_Closed(object sender System.EventArgs e) { greenPen.Dispose(); redPen.Dispose(); orangePen.Dispose(); }