iPhone iOS 如何在按钮的文本或图像下向 UIButton 添加线性渐变？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/10585103/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
iPhone iOS how to add linear gradient to a UIButton under the button's text or image?
提问by Alex Stone
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.
我正在通过向按钮添加线性渐变来创建漂亮的 UI 按钮。但是我不确定我需要在哪个索引上添加渐变。我目前拥有的代码将渐变放置在图像/文本上。
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!
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！
+(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];
}
}
回答by scord
Add it to the layer of your custom button:
将其添加到自定义按钮的图层：
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];
where customButtonis your custom UIButton.
customButton你的习惯在哪里UIButton。
回答by Mark Granoff
For what you are trying to achieve, always insert at index 0.
对于您要实现的目标，始终在索引 0 处插入。
I wrote an articleabout this sort of thing recently that you may find interesting.
回答by Gagandeep Gambhir
Swift 4
斯威夫特 4
@IBOutlet weak var gButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
let topGradientColor = UIColor.red
let bottomGradientColor = UIColor.yellow
let gradientLayer = CAGradientLayer()
gradientLayer.frame = gButton.bounds
gradientLayer.colors = [topGradientColor.cgColor, bottomGradientColor.cgColor]
//Vertical
//gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.0)
//gradientLayer.endPoint = CGPoint(x: 0.0, y: 1.0)
//Horizontal
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.0)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.0)
gButton.layer.insertSublayer(gradientLayer, at: 0)
}
回答by ggf85
Here is the code to achieve this
下面是代码来实现这一
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = <#View Variable Name#>.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)([UIColor colorWithRed:0.337 green:0.596 blue:1.000 alpha:1.000].CGColor),(id)([UIColor colorWithRed:0.757 green:0.459 blue:1.000 alpha:1.000].CGColor),(id)([UIColor colorWithRed:0.310 green:0.835 blue:1.000 alpha:1.000].CGColor),nil];
gradient.startPoint = CGPointMake(0.5,0.0);
gradient.endPoint = CGPointMake(0.5,1.0);
[<#View Variable name#>.layer insertSublayer:gradient atIndex:0];
I got this tool that makes it easy to select your colors and automatically output the code for the gradient. Very handy I use it everyday itunes.apple.com/gb/app/gradient-creator/id1031070259?mt=12
我得到了这个工具，可以轻松选择颜色并自动输出渐变代码。非常好用，我每天都用 itunes.apple.com/gb/app/gradient-creator/id1031070259?mt=12
