给某个view增加颜色渐变图层

//给某个view增加颜色透明度渐变图层

- (void) insertTransparentGradient {

    NSLog(@"%@",NSStringFromCGRect(self.imgView.bounds));

    UIColor *colorOne = [UIColor colorWithRed:(33/255.0)  green:(33/255.0)  blue:(33/255.0)  alpha:0.0];

    UIColor *colorTwo = [UIColor colorWithRed:(255/255.0)  green:(0/255.0)  blue:(0/255.0)  alpha:0.6];

    NSArray *colors = [NSArray arrayWithObjects:(id)colorOne.CGColor, colorTwo.CGColor, nil,nil];

    NSNumber *stopOne = [NSNumber numberWithFloat:0.0];

    NSNumber *stopTwo = [NSNumber numberWithFloat:1.0];

    NSArray *locations = [NSArray arrayWithObjects:stopOne, stopTwo, nil,nil];

    

    //crate gradient layer

    CAGradientLayer *headerLayer = [CAGradientLayer layer];

    

    headerLayer.colors = colors;

    headerLayer.locations = locations;

//        headerLayer.frame = self.imgView.bounds;

    headerLayer.frame = CGRectMake(0, 20, 212, 432);

    

    [self.imgView.layer addSublayer:headerLayer];

}

效果图:

 

参考链接:哈哈

demo链接:https://yunpan.cn/Oc6qWDkjxVyQGE （提取码：8abf）