_beginPaint _impl beginPaint beginPaintBuffered beginPath bezierTo clearCachedBitmap clearRect clearWindow clipPath clipRect closePath drawBitmap drawCachedBitmap drawCachedBitmap2 drawEllipse drawHandle drawLine drawPath drawRect drawTextAt endPaint getEncoder GiGdipCanvas hasCachedBitmap isBufferedDrawing lineTo moveTo quadTo restoreClip save saveCachedBitmap saveClip setBrush setPen thumbnailImage ~GiGdipCanvas

isBufferedDrawing() bool GiGdipCanvas::isBufferedDrawing ( ) const 返回当前是否在缓冲位图上绘图，调用endPaint()前有效