Sorry for the code dump, these are user control functions Private Zero PNGQuantPreviewControl_Resize ( Object sender, event ergres e) {createOffScreenBm (); Attract (); } Private Zero Making OffscreenBM () {offScreenBm = New Bitmap (This size, size, height, height); OffScreenGfx = Graphics.Fremight (OffscreenBM); } Private Zero Draw () {// Screenshots from the background. Filarentengel (transcrichers, 0, 0, offscreenbm. Wide, offscreenbm. High); // Skip Image PreviewScreen Gifs. Dowmage (PNG QuotePreview, getTopLeftPosition ()); // Apply to this photo box. Craigsfix (). Drymaz (OffscreenBM, 0, 0); } Therefore, when the control size changes, it rebuilds offscreen bitmaps to reflect the new shape and redraws the image. However, if I quickly change the size of the control bitmap does not fill it, there is a difference between right and / or bottom. I am quite new to C #, so maybe there is something obvious that I am doing wrong, or do I have any ideas to read the values of