iOS 裁剪图片指定区域方法

/**
 裁剪图片方法
 */
-(UIImage*)tailoringImage:(UIImage*)img Area:(CGRect)area{
    CGImageRef sourceImageRef = [img CGImage];//将UIImage转换成CGImageRef
    CGRect rect = CGRectMake(area.origin.x, area.origin.y, area.size.width, area.size.height);
    CGImageRef newImageRef = CGImageCreateWithImageInRect(sourceImageRef, rect);//按照给定的矩形区域进行剪裁
    UIImage *newImage = [UIImage imageWithCGImage:newImageRef];
    return newImage;
}