iOS——CALayer的shadow無效問題

標籤：

CALayer *sublayer = [CALayer layer];    sublayer.backgroundColor = [UIColor purpleColor].CGColor;    sublayer.shadowOffset = CGSizeMake(0, 3);    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:@"snaguosha.png"].CGImage;    imageLayer.masksToBounds = YES;    [sublayer addSublayer:imageLayer];    CALayer *customDrawn = [CALayer layer];    customDrawn.delegate = self;    customDrawn.backgroundColor = [UIColor greenColor].CGColor;    customDrawn.frame = CGRectMake(30, 250, 280, 200);    customDrawn.shadowOffset = CGSizeMake(0, 3);    customDrawn.shadowRadius = 5.0;    customDrawn.shadowColor = [UIColor blackColor].CGColor;    customDrawn.shadowOpacity = 1;    customDrawn.cornerRadius = 10.0;    customDrawn.borderColor = [UIColor blackColor].CGColor;    customDrawn.borderWidth = 2.0;    customDrawn.masksToBounds = YES;    [self.view.layer addSublayer:customDrawn];    [customDrawn setNeedsDisplay];

以上代碼預覽如下：

可以看到下方的部分沒有陰影，Why？看了半天也沒看出什麼不一樣，後來發現是因為customDrawn.masksToBounds = YES;這句代碼導然不存在，如果去掉這行代碼會是這樣的：

 

陰影出來了，但是圓角沒了。解決辦法很簡單，像上面圖片的方式，裡面套一層，masksToBounds作用在裡層，外層顯示陰影

iOS——CALayer的shadow無效問題