iPhone iOS如何在按钮的文本或图像下向UIButton添加线性渐变? [英] iPhone iOS how to add linear gradient to a UIButton under the button's text or image?

问题描述

我正在通过向按钮添加线性渐变来创建精美的 UI 按钮.但是我不确定我需要在哪个索引处添加渐变.我目前拥有的代码将渐变放在图像/文本上.

I'm working on creating fancy looking UIbuttons by adding linear gradient to the button. However I'm not sure at which index I need to add the gradient. The code that I have currently places the gradient over the image/text.

如何在文本/图像子层下的 UIButton 中插入子层?保持按钮的文本和图像可见对我来说很重要！

How can I insert a sublayer to a UIButton under the text/image sublayer? It is important for me to keep the text and the image of a button visible!

+(void)addLinearGradientToView:(UIView*)view TopColor:(UIColor*)topColor BottomColor:(UIColor*)bottomColor
{
    for(CALayer* layer in view.layer.sublayers)
    {
        if ([layer isKindOfClass:[CAGradientLayer class]])
        {
            [layer removeFromSuperlayer];
        }
    }
    CAGradientLayer* gradientLayer = [CAGradientLayer layer];

    gradientLayer.startPoint = CGPointMake(0.5, 0);
    gradientLayer.endPoint = CGPointMake(0.5,1);
    gradientLayer.frame = view.bounds;
    gradientLayer.colors = [NSArray arrayWithObjects:(id)[topColor CGColor], (id)[bottomColor CGColor], nil];
    //    [view.layer addSublayer:gradientLayer];
    if(view.layer.sublayers.count>0)
    {
        [view.layer insertSublayer:gradientLayer atIndex:view.layer.sublayers.count-2];
    }else {
        [view.layer addSublayer:gradientLayer];
    }
}

推荐答案

将其添加到自定义按钮的层:

Add it to the layer of your custom button:

CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = customButton.layer.bounds;

gradientLayer.colors = [NSArray arrayWithObjects:
                        (id)[UIColor colorWithWhite:1.0f alpha:0.1f].CGColor,
                        (id)[UIColor colorWithWhite:0.4f alpha:0.5f].CGColor,
                        nil];

gradientLayer.locations = [NSArray arrayWithObjects:
                           [NSNumber numberWithFloat:0.0f],
                           [NSNumber numberWithFloat:1.0f],
                           nil];

gradientLayer.cornerRadius = customButton.layer.cornerRadius;
[customButton.layer addSublayer:gradientLayer];

其中 customButton 是您的自定义 UIButton.

where customButton is your custom UIButton.

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