CALayer

[objc] view plaincopy在CODE上查看代码片派生到我的代码片

    <span style="font-size:18px;">为了确认设置</span><span style="font-size:18px; font-family: Arial, Helvetica, sans-serif;">imageView.layer.masksToBounds = YES</span><span style="font-family: Arial, Helvetica, sans-serif;">后,</span><span style="font-size:18px;"></span><p class="p1"><span style="font-family: Arial, Helvetica, sans-serif;">外面的view是否消失,改用了UIButton来验证.结果是存在的.</span></p>  

[objc] view plaincopy在CODE上查看代码片派生到我的代码片

    UIButton *imageView = [[UIButton alloc] initWithFrame:CGRectMake(30, 20, 200, 200)];  
    [imageView setBackgroundImage:[UIImage imageNamed:@"气球.png"] forState:UIControlStateNormal];  
    [self.view addSubview:imageView];  
      
    /*****--第一种:图层当作一个属性来使用 --------*/  
    //CALayer图层前需要导入一个系统库  
    //设置图层的宽度  
    [imageView.layer setBorderWidth:5];  
    //设置图层的弧度  
    [imageView.layer setCornerRadius:100];  
    //设置颜色  
    [imageView.layer setBorderColor:[UIColor purpleColor].CGColor];  
    //设置bounds外消失  
    //imageView.layer.masksToBounds = YES;//默认为NO,如果设置为YES时,连阴影也会没有  
    //设置透明度  
    imageView.layer.opacity = 0.9;  
      
    //设置阴影  
    imageView.layer.shadowColor = [UIColor redColor].CGColor;  
    //设置阴影偏移量  
    imageView.layer.shadowOffset = CGSizeMake(30, 30);  
    //设置阴影透明度,默认是全透明,所以设置才能看到  
    imageView.layer.shadowOpacity = 0.9f;  
    //设置阴影弧度  
    imageView.layer.shadowRadius = 50;  
      
     /*****--第二种:图层单独使用 --------*/  
    CALayer *layer1 = [CALayer layer];//便利构造器创建一个图层  
    //设置一个图层的内容  
    layer1.contents = (id)[UIImage imageNamed:@"气球.png"].CGImage;  
    //设置图层的fram  
    layer1.frame = CGRectMake(30, 260, 200, 200);  
    //把图层add到图层上面  
    [self.view.layer addSublayer:layer1];  
    [layer1 setCornerRadius :100];  


上面有一个问题就是:

我设置imageView.layer.masksToBounds = YES后,连阴影部分都消失了.

为了解决这个问题,我们可以采用两层图层;代码如下:

[objc] view plaincopy在CODE上查看代码片派生到我的代码片

    CALayer *sublayer =[CALayer layer];  
    sublayer.backgroundColor =[UIColor blueColor].CGColor;  
    sublayer.shadowOffset = CGSizeMake(3, 10);  
    sublayer.shadowRadius =5.0;  
    sublayer.shadowColor =[UIColor blackColor].CGColor;  
    sublayer.shadowOpacity =0.8;  
    sublayer.frame = CGRectMake(30, 30, 128, 192);  
    sublayer.borderColor =[UIColor blackColor].CGColor;  
    sublayer.borderWidth =2.0;  
    sublayer.cornerRadius =10.0;  
    [self.view.layer addSublayer:sublayer];  
      
    CALayer *imageLayer =[CALayer layer];  
    imageLayer.frame = sublayer.bounds;  
    imageLayer.cornerRadius =10.0;  
    imageLayer.contents =(id)[UIImage imageNamed:@"气球.png"].CGImage;  
    imageLayer.masksToBounds =YES;  
    [sublayer addSublayer:imageLayer];