Question

I have a very fast loop which renders animation in a Bitmap buffer and adds filter to it (by using LockBits/UnlockBits to access to the raw data and Marshaling changes to it.) in an independent thread.

I wanted to figure out a way to display the render on the Form, real-time, so I created a PictureBox and linked its Image to the bitmap I created. Everytime immediately after the bitmap is unlocked, I refreshed the PictureBox (using delegate, to do cross-threading) so that the rendering is updated properly.

It’s totally fine and works very fast, but one big problem came out as I tried dragging the form to the border of the screen, to see if any bug would appear, and oops, the app collapse..saying ‘the bitmap is being locked’ This happens when either there’s other window moving above the PictureBox or the PictureBox is dragged partially out of the screen. I suspice it because PictureBox can refresh itself when redraw is neccessary, and it does when the bitmap is still being locked. So…any way to sovle this problem? Or anyother ways to render the my animation better?

Answer 1

You can’t do that.

Instead, you should copy the image (on the background thread) and put the copy in the PictureBox.

For better performance, you can swap between two images to avoid creating too many images.