图片(UIImage*) img
要截取的起始坐标sx:(int) sx1 sy:(int)sy1
要截取的长度和宽度sw:(int) sw1 sh:(int) sh1
最终要显示的坐标desx:(int) desx1 desy:(int)desy1
-(UIImage*)objectiveDrawRegion:(UIImage*) img sx:(int) sx1 sy:(int)sy1 sw:(int) sw1 sh:(int) sh1 desx:(int) desx1 desy:(int)desy1{[self saveImage:img name:@"objectiveDrawRegion1.png"];//创建图片缓冲void *imageDataRegion=malloc(screenWidth*screenHeight*32); CGColorSpaceRef iColorSpaceRegion=CGColorSpaceCreateDeviceRGB();CGContextRef iDeviceRegion=CGBitmapContextCreate(imageDataRegion,screenWidth,screenHeight,8,4*screenWidth,iColorSpaceRegion,kCGImageAlphaPremultipliedLast);//剪切区域CGRect clipRegion=CGRectMake(sx1,sy1,sw1,sh1);CGContextClipToRect(iDeviceRegion, clipRegion);CGFloat widthf=img.size.width;CGFloat heightf=img.size.height;CGRect cg=CGRectMake(0.0, 0.0, widthf, heightf);//画底图CGContextDrawImage(iDeviceRegion,cg, img.CGImage);//将缓冲形成图片CGImageRef ioffRegion=CGBitmapContextCreateImage(iDeviceRegion);CGRect cg1=CGRectMake(desx1, desy1, sw1, sh1);
UIImage *ui=[UIImage imageWithCGImage:ioffRegion];
CGContextDrawImage(当前context,cg1, ui.CGImage);//清除缓冲CGColorSpaceRelease(iColorSpaceRegion);CGContextRelease(iDeviceRegion);CGImageRelease(ioffRegion);free(imageDataRegion);
// iDeviceRegion=NULL;
// imageDataRegion=0;return ui;
}