做iOS开发的都会知道，给一个视图设置圆角只需要设置layer.cornerRadius，并masksToBounds值为YES即可，但若还想设置阴影效果，发现圆角和阴影是不兼容的，这里提供两种方法同时设置圆角和阴影
①父视图阴影，子视图圆角
UIView *shadowView = [[UIView alloc]initWithFrame:CGRectMake(100, 100, 200, 200)];
[self.view addSubview:shadowView];
shadowView.layer.shadowColor = [UIColor blackColor].CGColor;
shadowView.layer.shadowOffset = CGSizeMake(0, 0);
shadowView.layer.shadowOpacity = 0.8;
shadowView.layer.shadowRadius = 9.0;
shadowView.layer.cornerRadius = 9.0;
UILabel *label = [[UILabel alloc] initWithFrame:shadowView.bounds];
label.backgroundColor =[UIColor redColor];
label.layer.cornerRadius = 10;
label.layer.masksToBounds = YES;
[shadowView addSubview:label];
②高效的使用shadowPath
UIView *view = [[UIView alloc]initWithFrame:CGRectMake(100, 400, 200, 200)];
view.backgroundColor = [UIColor redColor];
view.layer.shadowColor = [UIColor blackColor].CGColor;//阴影颜色
view.layer.shadowOpacity = 0.8;//阴影透明度，默认为0，如果不设置的话看不到阴影，切记，这是个大坑
view.layer.shadowOffset = CGSizeMake(0, 0);//设置偏移量
view.layer.cornerRadius = 9.0;
view.layer.shadowRadius = 9.0;
[self.view addSubview:view];
//参数依次为大小，设置四个角圆角状态，圆角曲度
view.layer.shadowPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:5 cornerRadii:CGSizeMake(0, 0)].CGPath;
效果图如下
阴影
