How to thread safe call to PictureBox.Image in c# , currently gives one of 3 errors?

Depends on which timer you are using. SendDataFast definitely isn't because you used a System.Threading.Timer.

Depends on which timer you are using. SendDataFast definitely isn't because you used a System.Threading.Timer. If you take a look at the MSDN documentation on System.Threading.

Timer you'll see the following System.Threading. Timer is a simple, lightweight timer that uses callback methods and is served by thread pool threads.It is not recommended for use with Windows Forms, because its callbacks do not occur on the user interface thread. System.Windows.Forms.

Timer is a better choice for use with Windows Forms. Choice for use with Windows Forms. This is explains why you're getting freezes.

The callback method executed by the timer should be reentrant, because it is called on ThreadPool threads. The callback can be executed simultaneously on two thread pool threads if the timer interval is less than the time required to execute the callback, or if all thread pool threads are in use and the callback is queued multiple times. Which means if your function fails to execute in under 33 ms the function will be called again.

This is probably the case and why you're getting the exceptions you're seeing. Two or more threads are trying to use the same file. You may also have multiple threads trying to allocate a large block of Memory and one fails to get the block of the size you've requested.

Not sure why you're getting the argument exception but it may be because of the previous two. For this reason I prefer the System.Timers.Timer. It has an AutoReset Property that set false.

Then at the end of my function I call Timer.Start. You can accomplish the same thing with the other timers but its a little tricker. Here are three links you might find useful Article on Comparison of the Timer Classes Jon Skeet Answer on a Begin Invoke Question Eric Lippert Blog on what an OutOfMemory Exception likely is.

Basically the system can be "armed" and while its armed the timer is invoked and as to not miss anything happening its called every 33ms (which I figured was close to my cameras fps). – Codejoy Sep 12 '10 at 8:12 if you want to fire every 33ms you will need to ensure that process frame is reenrant. – Conrad Frix Sep 12 '10 at 16:38.

I think while seeing this line double value = detector. ProcessFrame(new Bitmap(picCapture. Image)); you are trying to modify the picCapture.

Image which is a Picturebox image and you are doing this every 33 millisecs. 1st What this detector. ProcessFrame do?2- You should pass the actual image uri to the New Bitmap rather than using a Image which is the source of PictureBox 3- Why are you creating more timers in tick event?

Basically if that double value is greater than some number, it detects movement and I want an event to fire 2 seconds after this movement. So thats what that other timer is for, its a scheduler... the detector. ProcessFrame checks to see if there is movement between the two frames... that is from the library I am using: AForge.Vision.Motion.

How do I pass the URI of the image instead of the image itself? – Codejoy Sep 12 '10 at 7:15 The timer is set to 33 milliseconds. It has a resolution of about 20 milliseconds.

– Henk Holterman Sep 12 '10 at 7:41.

For OutOfMemoryException, I would suggest replacing double value = detector. ProcessFrame(new Bitmap(picCapture. Image)); with double value; using(Bitmap bmp = new Bitmap(picCapture.

Image)) { value = detector. ProcessFrame(bmp); } so your temporary Bitmap will be disposed as it should be.

Yes, looks better. But the Image class is strange, I remember something about it throwing OOM for several reasons unrelated to memory. – Henk Holterman Sep 12 '10 at 9:05.

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