效果如下:
主要用到了Layer上的渐变层,核心代码如下,关于CALaer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]; }
code实现透明度渐变和颜色渐变的view,布布扣,bubuko.com
原文地址:http://blog.csdn.net/xunyn/article/details/30727863