iOS阴影

 但是如果把masksToBounds设置为yes就没有阴影了

    UIButton *view = [[UIButton alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];
    view.backgroundColor = [UIColor redColor];
    view.layer.shadowColor = [[UIColor grayColor] CGColor];//阴影的颜色
    view.layer.shadowOpacity =0.5f;   // 阴影透明度
    view.layer.shadowOffset = CGSizeMake(10.0,10.0f); // 阴影的范围
    view.layer.shadowRadius = 5;  // 阴影扩散的范围控制
    view.layer.cornerRadius = 10;
//    view.layer.masksToBounds = YES;
    [self.view addSubview:view];