ios 截取view上内容 返回image 保证清晰度

直接调用下面方法，传入要截取图片的view，返回image，能保证清晰度

//获取截图-(UIImage *)getImageFromView:(UIView *)orgView{    CGSize s = orgView.bounds.size;    UIGraphicsBeginImageContextWithOptions(s, NO, [UIScreen mainScreen].scale);        [orgView.layer renderInContext:UIGraphicsGetCurrentContext()];        UIImage*image = UIGraphicsGetImageFromCurrentImageContext();        UIGraphicsEndImageContext();        return image;}