#import "RootViewController.h"
@interface RootViewController (){
CAGradientLayer *gradientLayer;
NSTimer *timer;
}
@end
@implementation RootViewController
- (void)viewDidLoad {
[super viewDidLoad];
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"美女图.jpg"]];
imageView.frame = self.view.bounds;
gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = imageView.bounds;
[imageView.layer addSublayer:gradientLayer];
[self.view addSubview:imageView];
[imageView release];
//设置颜色渐变方向
gradientLayer.startPoint = CGPointMake(0, 0);
gradientLayer.endPoint = CGPointMake(0, 1);
//设定颜色组
gradientLayer.colors = @[(__bridge id)[UIColor clearColor].CGColor, (__bridge id)[UIColor purpleColor].CGColor];//((__bridge id)把颜色转化为一个对象)
//设定颜色分割点
gradientLayer.locations = @[@(0.5f), @(1.0f)];
//设置时间定时器
timer = [NSTimer scheduledTimerWithTimeInterval:2.0f target:self selector:@selector(TimeChange) userInfo:nil repeats:YES];
}
- (void)TimeChange{
//定时随机颜色
gradientLayer.colors = @[(id)[[UIColor clearColor] CGColor], (id)[UIColor colorWithRed:arc4random() % 256 / 255. green:arc4random() % 256 / 255. blue:arc4random() % 256 / 255. alpha:1.0].CGColor];
gradientLayer.locations = @[@(arc4random() % 10 / 10.0f), @(1.0f)];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end