- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window =
[[UIWindowalloc]
initWithFrame:[[UIScreenmainScreen]
bounds]];
UILabel
*lab1=[[UILabelalloc]initWithFrame:CGRectMake(20,
30, 100,
30)];
lab1.text=@"helloworld";
//设置tag属性
lab1.tag=1;
UITapGestureRecognizer
*tap=[[UITapGestureRecognizeralloc]initWithTarget:selfaction:@selector(randomColor:)];
[lab1 addGestureRecognizer:tap];
lab1.userInteractionEnabled=YES;
[self.window
addSubview:lab1];
self.window.backgroundColor
= [UIColorwhiteColor];
[self.windowmakeKeyAndVisible];
returnYES;
}
-(void)randomColor:(UITapGestureRecognizer
*)gestureRecognizer
{
//通过tag属性来获取label
UILabel *lab=(UILabel
*)[self.window
viewWithTag:1];
lab.backgroundColor=[UIColorcolorWithRed:arc4random()%256/255.0green:arc4random()%256/255.0blue:arc4random()%256/255.0alpha:1];
}