IOS 二张图片合并

-(UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2
{
UIGraphicsBeginImageContext(image2.size);

//Draw image2
[image2 drawInRect:CGRectMake(0, 0, image2.size.width, image2.size.height)];

//Draw image1
[image1 drawInRect:CGRectMake(20, 20, image1.size.width, image1.size.height)];

UIImage *resultImage=UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return resultImage;
}