将图片保存到相册中

#pragma mark 保存按钮点击事件
- (IBAction)saveClick:(UIButton *)sender {

    if (self.saveImage) {
        UIImageWriteToSavedPhotosAlbum(self.saveImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
    }
}

//指定回调方法
-(void)image:(UIImage*)image didFinishSavingWithError:(NSError*)error contextInfo:(void*)contextInfo {
    if(!error){
        NSLog(@"保存成功");
    }else{
        NSLog(@"保存失败");
    }
}