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