Retrieves the device context into which the current bitmap is selected 得到选入当前位图的设备描述表。
Copies a bitmap from the source device context to this current device context 从源设备描述表复制位图到当前设备描述表。
Copies a bitmap with transparent color from the source device context to this current device context 从源设备描述表复制一个带透明色的位图到当前设备描述表。
Performs a bit - block transfer from a rectangle in a source device context into a parallelogram in a destination device context 实现从一个源设备描述表传送一个比特块到目标设备描述表的一个平行四边形区域。