Interrupt main app while executing control

Question

Hi there. I'm working on a app that needs to animate gifs. So I've created a costum control to execute the params needed to this operation... The problem is that I can't stop the main app while the gif is playing. What happens is that the control where the gif is processing is being refreshed but the main code the one that called the app doesn't wait until the end of the gif. It's something like: // Loads the image animaGif.CarregaImagem(Image.FromFile(Environment.CurrentDirectory+\Imagens\BolaCanhao.gif)); // Starts the animation animaGif.Start(posX*17 posY*17); // Should wait until the animation ended what doesn't happen.. it just continues The ideal was to implement a flag to extend the usibility of the control... like in WinMM PlaySound where there is a flag to play the sound sync/async and when Sync is activated the app waits until de sound is over. Regards David Sanguinetti

david_sanguinetti · Answer

In fact I was missing a line code! Application.DoEvents(); After searching a little more in the net I found a post that contained an excelente alternative to the ImageAnimator but it was in VB; It already contained a way to delay the real frame delays. Remember this code is only to execute an animation of a GIF synchronously (if think this is the way it's written) since ImageAnimator when running proceeds animating the GIF in background. This is the convertion to C#.. Hope it may be usefull some day for someone who needs (like I did): // Inicializa variáveis this.contFrames = 0; // Conta número de frames this.numFrames = gifAnimado.GetFrameCount(new System.Drawing.Imaging.FrameDimension(gifAnimado.FrameDimensionsList[0]))-1; // Variáveis que captam o delay entre os frames int propertyTagFrameDelay = 0x5100; // Tag com o valor da propriedade do delay PropertyItem propItem = gifAnimado.GetPropertyItem(propertyTagFrameDelay); // Capta a propriedade byte[] bytes = propItem.Value; // Guarda num array os bytes correspondentes ao valor do delay // Cria um array de inteiros com os delays entre os frames int[] delays = new int[numFrames]; // Preenche-o for(int i=0; i<numFrames; i++) delays[i] = BitConverter.ToInt32(bytes i*4); // Converte os bytes para inteiros // Corre todos os frames do gif for(int contFrames=0; contFrames<numFrames; contFrames++) { // Selecciona o Frame a ser desenhado gifAnimado.SelectActiveFrame(new FrameDimension(gifAnimado.FrameDimensionsList[0]) contFrames); // Grava a imagem para a stream de memória gifAnimado.Save(streamImagem System.Drawing.Imaging.ImageFormat.Tiff); // Refresca o ecrã this.Invalidate(); // Processa todas as windows messages em queue neste caso refrescar Application.DoEvents(); // Aguarda o tempo do frame System.Threading.Thread.Sleep(delays[contFrames]*10); } The comments are in portuguese my nationality. Thank you very much for the trying to help spgilmore.

spgilmore · Answer

Did you make sure to call Thread.Sleep()? It really should work...

david_sanguinetti · Answer

In fact i've tried that already but with no results... At least not the ones i need! lol Thanks anyway ;)

spgilmore · Answer

If I understand correctly the main form waits for the the animaGif.Start() method to complete before it responds? Your custom control should use a timer or a thread to do its pausing between frames and should use a delegate to the custom control to trigger a frame draw. The timer or thread may also be outside the custom control and an external process (like the main form) may simply call a method like animaGif.NextFrame() for example. I suspect that this is not what you want however since animated GIFs specify their own loops and delays.

Interrupt main app, while executing control