private void ClearBitmap() { if (locatPlus != null) { drawShapeDC.EraseLocatShape(locatPlus.GetLocatShapePoints(), locatPlus.GetPointColors()); } if (movePlus != null) { drawShapeDC.EraseLocatShape(movePlus.GetLocatShapePoints(), movePlus.GetPointColors()); } drawShapeDC.ClearBitmap(); if (clothClamps != null) { for (int i = 0; i < clothClamps.Length; i++) { drawShapeDC.DrawRange(clothClamps[i].RangeLinePoints()); drawShapeDC.DrawClothCramp(clothClamps[i].ClothClampRect, clothClamps[i].ClothClampPoint); } } }