12

UILabel由于某些原因，我试图在CAGradientLayer我的文本中添加一个渐变层。我做错什么了吗

- (void)viewDidLoad {
   [super viewDidLoad];

   CAGradientLayer *gradient = [CAGradientLayer layer];
   gradient.frame = CGRectMake(0, 0, myLabel.frame.size.width, myLabel.frame.size.height);
   gradient.colors = myColors;
   [myLabel.layer insertSublayer:gradient atIndex:0];
}
4

3 回答 3

12

覆盖标签的CAGradientLayer文本，因为文本是由您通过添加子层明确覆盖的超级层的内容绘制的。

您最简单的解决方案是使用两个视图。UIView您覆盖+[UIView layerClass]并返回的子类[CAGradientLayer]。添加一个好的初始化方法来设置你的渐变。

下一个小狗添加UILabel作为自定义渐变视图的子视图。

于 2011-08-26T19:18:54.577 回答
1

我有同样的问题。我使用这种方法来获取形状图层的参考，或者如果它不存在则生成它。此方法确保将该图层放在后面，使其不会覆盖标签文本图层。只需使用它，你应该一切都好，不需要额外的子类。

- (CAShapeLayer*) getShapeLayerForObject: (UIView*) object{
    CAShapeLayer *maskLayer;
    int loc = -1;
    for(int x = 0; x < object.layer.sublayers.count; x++){
        if([[object.layer.sublayers objectAtIndex:x] isKindOfClass:[CAShapeLayer class]]){
            loc = x;
            break;
        }
    }
    if(loc > -1){
        maskLayer = (CAShapeLayer*) [object.layer.sublayers objectAtIndex:loc];
    }else{
        maskLayer = [[CAShapeLayer alloc] init];
        [object.layer insertSublayer:maskLayer atIndex:0];

    }
    return maskLayer;
}
于 2016-04-04T18:30:51.880 回答
0

例如，如果您需要子类化您的UILabel，然后添加一些CALayer覆盖文本的内容，建议添加CATextLayer到您的CALayer，这是一个快速示例：

@IBDesignable class BWRoundedLabel: UILabel {

    override var text: String? {
        didSet {
            updateView()
        }
    }

    @IBInspectable override var shadowColor: UIColor? {

        didSet {
            updateView()
        }
    }

    private func updateView() {

        let width = bounds.size.width - 1
        let height = bounds.size.height - 1

        let shadowLayer = CAShapeLayer()
        shadowLayer.path = UIBezierPath(roundedRect: CGRectMake(0, 0, width, height), cornerRadius: width/2).CGPath
        shadowLayer.fillColor = UIColor.yellowOrange().CGColor
        shadowLayer.shadowColor = shadowColor?.CGColor
        shadowLayer.shadowPath = shadowLayer.path
        shadowLayer.shadowOffset = CGSize(width: 0, height: 1.0)
        shadowLayer.shadowOpacity = 1
        shadowLayer.shadowRadius = 0

        let textLayer = CATextLayer()
        textLayer.foregroundColor = UIColor.whiteColor().CGColor
        textLayer.string = text
        textLayer.fontSize = font.pointSize
        textLayer.font = "Calibri-Bold"
        textLayer.alignmentMode = kCAAlignmentCenter
        textLayer.frame = CGRectMake(0, (height - 16)/2, width, 16)

        if let sublayers = layer.sublayers {
            for sublayer in sublayers {
                sublayer.removeFromSuperlayer()
            }
        }

        layer.insertSublayer(shadowLayer, atIndex: 0)
        layer.insertSublayer(textLayer, atIndex: 1)
    }
}
于 2016-05-02T10:27:09.533 回答