code实现透明度渐变和颜色渐变的view

最新推荐文章于 2023-02-18 23:55:29 发布

xunyn

最新推荐文章于 2023-02-18 23:55:29 发布

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分类专栏： IOS开发文章标签： ios gradient view la

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最近用code写了些view上的渐变效果，使得app的UI特效不必全部依赖美工出的图片。

效果如下：

主要用到了Layer上的渐变层，核心代码如下，关于CALayer的使用可参考

//Transparent Gradient Layer
- (void) insertTransparentGradient {
    UIColor *colorOne = [UIColor colorWithRed:(33/255.0)  green:(33/255.0)  blue:(33/255.0)  alpha:0.0];
    UIColor *colorTwo = [UIColor colorWithRed:(33/255.0)  green:(33/255.0)  blue:(33/255.0)  alpha:1.0];
    NSArray *colors = [NSArray arrayWithObjects:(id)colorOne.CGColor, colorTwo.CGColor, nil];
    NSNumber *stopOne = [NSNumber numberWithFloat:0.0];
    NSNumber *stopTwo = [NSNumber numberWithFloat:1.0];
    NSArray *locations = [NSArray arrayWithObjects:stopOne, stopTwo, nil];
    
    //crate gradient layer
    CAGradientLayer *headerLayer = [CAGradientLayer layer];
    
    headerLayer.colors = colors;
    headerLayer.locations = locations;
    headerLayer.frame = self.bounds;
    
    [self.layer insertSublayer:headerLayer atIndex:0];
}


//color gradient layer
- (void) insertColorGradient {
    
    UIColor *colorOne = [UIColor colorWithRed:(255/255.0) green:(255/255.0) blue:(255/255.0) alpha:1.0];
    UIColor *colorTwo = [UIColor colorWithRed:(33/255.0)  green:(33/255.0)  blue:(33/255.0)  alpha:1.0];
    
    NSArray *colors = [NSArray arrayWithObjects:(id)colorOne.CGColor, colorTwo.CGColor, nil];
    NSNumber *stopOne = [NSNumber numberWithFloat:0.0];
    NSNumber *stopTwo = [NSNumber numberWithFloat:1.0];
    
    NSArray *locations = [NSArray arrayWithObjects:stopOne, stopTwo, nil];
    CAGradientLayer *headerLayer = [CAGradientLayer layer];
    headerLayer.colors = colors;
    headerLayer.locations = locations;
    headerLayer.frame = self.bounds;
    
    [self.layer insertSublayer:headerLayer above:0];
    
}

Demo下载地址