线程

- (void)viewDidLoad {

[superview DidLoad];

UIButton *button1 = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 100, 40)];

[button1 setTitle:@"数字输出"forState:UIControlStateNormal];

button1.backgroundColor= [UIColor blueColor];

button1.layer.cornerRadius= 15;

[button1 addTarget:self action:@selector(numberOut) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:button1];

UIButton *button2 = [[UIButton alloc] initWithFrame:CGRectMake(100, 200, 100, 40)];

button2.layer.cornerRadius= 15;

[button2 setTitle:@"改变颜色" forState:UIControlStateNormal];

button2.backgroundColor= [UIColorblueColor];

[button2 addTarget:self action:@selector(changeColor) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:button2];

}

- (void)numberOut {

NSLog(@"输出数字");

//主线程卡死 单线程:同一时间只能做一种事情

//开辟一个发线程让数字输出方法在分线程中去执行

//创建一个线程用来执行耗时和大数据

// self :表示当前类调用这个方法

// object :参数,不需要就nil

//第一种线程创建方式：需要要手动开启

//NSThread  *thread = [[NSThread alloc] initWithTarget:self selector:@selector(out) object:nil];

//线程开启

//[thread start];

//第二种线程创建方式：自动开启

//[NSThread detachNewThreadSelector:@selector(thread2) toTarget:self withObject:nil];

//[NSThread detachNewThreadSelector:<#(SEL)#> toTarget:<#(id)#> withObject:<#(id)#>]

//第三种线程创建方式:隐式创建免开启

[self performSelectorInBackground:@selector(thread3) withObject:nil];

//[self performSelectorInBackground:<#(SEL)#> withObject:<#(id)#>]

//线程对应要执行的方法结束后(执行完毕)线程自动消失,如果想让这个分线程一直存在,那么就要要保证这个线程对应的方法一直在执行,

}

- (void)thread3 {

NSLog(@"隐式创建免开启");

}

- (void)thread2 {

NSLog(@"第二种创建线程方式自动开启");

}

- (void)out {

//判断当前线程是否是主线程是主线程就返回YES 分线程就返回NO

BOOL isMain = [NSThread isMainThread];

NSLog(@"%d",isMain);

if(isMain ==YES) {

NSLog(@"主线程");

} else {

NSLog(@"分线程");

}

staticinti =0;

for( ;  ; ) {

i ++;

if(i == 100) {

i = 0;

}

NSLog(@"%d",i);

//线程睡眠让当前线程睡眠1秒钟后再执行

[NSThread sleepForTimeInterval:1];

//分线程跳到主线程

//方法的延时

// waitUntilDone BOOL类型YES表示等待当前方法执行完才返回主线程. NO表示执行到这句时就返回到主线程

[self performSelectorOnMainThread:@selector(numberOut) withObject:nil waitUntilDone:NO];

}

- (void)changeColor {

staticinta =1;

a++;

if(a %2 == 0) {

self.view.backgroundColor= [UIColorredColor];

} else {

self.view.backgroundColor= [UIColormagentaColor];

}

NSLog(@"改变颜色");

}