iOS基础之响应者链

            #import
            "
            RootViewController.h
            "
            @interface
             RootViewController ()


            @end
            @implementation
             RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    //创建一个UIImageView
    UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(65, 65, 250, 250)];
    imageView.backgroundColor = [UIColor greenColor];
    //打开用户交互
    imageView.userInteractionEnabled = YES;
    //响应者链阻断之后，完成不了检测过程，检测过程完成不了，所以事件就触发不了
    //而空间阻断响应者链就是关闭用户交互，默认关闭用户交互的控件有UIImageView和UILabel
    //以后项目开发中，如果想让UIImageView和UILabel响应时间，必须将其交互打开    [self.view addSubview:imageView];
    [imageView release];
    
    //创建一个UIButton加到UIImageView上面
    UIButton *button =[UIButton buttonWithType:UIButtonTypeCustom];
    button.frame = CGRectMake(50, 50, 150, 80);
    [button setTitle:@"xxx" forState:UIControlStateNormal];
    [button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    //修改按钮显示文本的字体，先要找到titlelabel，按钮是个组合控件
    button.titleLabel.font = [UIFont boldSystemFontOfSize:20];
    [button addTarget:self action:@selector(click) forControlEvents:UIControlEventTouchUpInside];
    [imageView addSubview:button];
    
    
    
}

-(void)click{
    NSLog(@"你好");
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.}



@end