UI基础--定时器和视图移动

我们先声明一个定时器:

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

//私有
{
    //定义一个定时器对象
    //可以在固定时间内发送一个消息,通过消息来调用响应的函数.
    //通过此函数可以在固定的时间段完成一个任务
    NSTimer* _timerView;
}

//共有
@property (nonatomic, strong) NSTimer *timerView;


@end

创建按钮并添加按钮事件:

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

//属性和成员变量的同步
@synthesize timerView = _timerView;

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    self.view.backgroundColor = [UIColor blackColor];
    
    //创建一个启动按钮
    UIButton *btnStart = [UIButton buttonWithType:UIButtonTypeCustom];
    btnStart.frame = CGRectMake(100, 100, 100, 100);
    [btnStart setTitle:@"启动定时器" forState:UIControlStateNormal];
    
    [self.view addSubview:btnStart];
    
    //添加开始定时器按钮事件
    [btnStart addTarget:self action:@selector(btnStart:) forControlEvents:UIControlEventTouchUpInside];
    
    //创建一个停止按钮
    UIButton *btnStop =  [UIButton buttonWithType:UIButtonTypeCustom];
    btnStop.frame = CGRectMake(100, 300, 100, 100);
    [btnStop setTitle:@"停止定时器" forState:UIControlStateNormal];
    [self.view addSubview:btnStop];
    //添加停止定时器按钮事件
    [btnStop addTarget:self action:@selector(btnStopAct:) forControlEvents:UIControlEventTouchUpInside];
    
    
    //创建一个View
    UIView *view = [[UIView alloc]init];
    view.frame = CGRectMake(0, 0, 80, 80);
    view.backgroundColor = [UIColor whiteColor];
    //可以通过父视图对象以及view的标签值,可以获得相应的视图对象
    view.tag = 101;
    [self.view addSubview:view];
    
    
}

- (void)btnStart:(UIButton *)btn{
  
    //通过类方法创建一个定时器并启动
    //p1.每隔多长事件调用此函数.
    //p2.实现定时器函数的对象(指针)
    //p3.定时器函数对象
    //p4.可以传入一个参数,无参传nil;(类型是id)
    //p5.定时器是否重复调用
    //返回值为一个新建好的定时器对象
   _timerView = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updataTimer:) userInfo:@"小明" repeats:YES];
    
    
}

//停止定时器
- (void)btnStopAct:(UIButton *)btn{
    
    //停止定时器
    [_timerView invalidate];
    _timerView = nil;
    
}
//定时器函数
- (void)updataTimer:(NSTimer *)timerstart{
    
    //根据view.tag值获取对应的视图对象
    UIView *view = [self.view viewWithTag:101];
    view.frame = CGRectMake(view.frame.origin.x +5, view.frame.origin.y + 5, 80, 80);
    
    
    
}