Question

如何在ios中为按钮提供水平渐变颜色？

我试图在水平方向上给出按钮渐变颜色为蓝色，但没有正确输出。

Answer 1

我不确定但是试试这段代码

CAGradientLayer *btnGradient = [CAGradientLayer layer];
btnGradient.frame = btn.bounds;
btnGradient.colors = [NSArray arrayWithObjects:
                              (id)[[UIColor colorWithRed:102.0f / 255.0f green:102.0f / 255.0f blue:102.0f / 255.0f alpha:1.0f] CGColor],
                              (id)[[UIColor colorWithRed:51.0f / 255.0f green:51.0f / 255.0f blue:51.0f / 255.0f alpha:1.0f] CGColor],
                             nil];
[yourbtn.layer insertSublayer:btnGradient atIndex:0];

Answer 2

这将允许您为按钮插入水平渐变，其中第一种颜色在左侧，第二种颜色在右侧：

extension UIView {
    func insertHorizontalGradient(_ color1: UIColor, _ color2: UIColor) {
        let gradient = CAGradientLayer()
        gradient.colors = [color1.cgColor, color2.cgColor]
        gradient.transform = CATransform3DMakeRotation(CGFloat.pi / 2, 0, 0, 1)
        gradient.frame = bounds
        layer.insertSublayer(gradient, at: 0)
    }
}

您可能希望保留对图层的引用以调整其框架的大小，否则请务必在按钮框架确定后再调用它。

Answer 3

您可以尝试以下代码：

{
    UIColor *transBgColor = [UIColor colorWithWhite:1.0 alpha:0.0];
    UIColor *black = [UIColor blackColor];
    CAGradientLayer *maskLayer = [CAGradientLayer layer];
    maskLayer.opacity = 0.8;
    maskLayer.colors = [NSArray arrayWithObjects:(id)black.CGColor, 
    (id)transBgColor.CGColor, (id)transBgColor.CGColor, (id)black.CGColor, nil];

    // Horizontal - commenting these two lines will make the gradient vertical
    maskLayer.startPoint = CGPointMake(0.0, 0.5);
    maskLayer.endPoint = CGPointMake(1.0, 0.5);

    NSNumber *gradTopStart = [NSNumber numberWithFloat:0.0];
    NSNumber *gradTopEnd = [NSNumber numberWithFloat:0.4];
    NSNumber *gradBottomStart = [NSNumber numberWithFloat:0.6];
    NSNumber *gradBottomEnd = [NSNumber numberWithFloat:1.0];
    maskLayer.locations = @[gradTopStart, gradTopEnd, gradBottomStart, gradBottomEnd];

    maskLayer.bounds = container.bounds;
    maskLayer.anchorPoint = CGPointZero;
    [container.layer addSublayer:maskLayer];
}

如何在ios中为按钮提供水平渐变颜色

3 个答案: