多线程,异步存在的原因(程序运行时卡顿/假死状态),耗时操作移步到后台操作;
模拟耗时操作
// ViewController.m // 01-处理耗时操作 #import "ViewController.h" @interface ViewController () @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. } - (IBAction)buttonClick { for (NSInteger i = 0; i<50000; i++) { NSLog(@"------buttonClick---%zd", i); } } @end
02-了解-pthread
// ViewController.m // 02-了解-pthread #import "ViewController.h" #import <pthread.h> @interface ViewController () @end @implementation ViewController void * run(void *param) { for (NSInteger i = 0; i<50000; i++) { NSLog(@"------buttonClick---%zd--%@", i, [NSThread currentThread]); } return NULL; } - (IBAction)buttonClick:(id)sender { pthread_t thread; //定义一个线程对象thread,他是一个地址。NULL是线程的一个属性;指向函数的指针;
pthread_create(<#pthread_t _Nullable *restrict _Nonnull#>, <#const pthread_attr_t *restrict _Nullable#>,
<#void * _Nullable (* _Nonnull)(void * _Nullable)#>, <#void *restrict _Nullable#>);
pthread_create(&thread, NULL, run, NULL); pthread_t thread2; pthread_create(&thread2, NULL, run, NULL); }
@end
03-掌握-NSThread
// ViewController.m // 03-掌握-NSThread #import "ViewController.h" #import "XMGThread.h" @interface ViewController () @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {//屏幕点击的时候会掉用的事件; [self createThread3]; } - (void)createThread3 { //隐式创建并启动线程 [self performSelectorInBackground:@selector(run:) withObject:@"jack"]; //连self都不传了。。。。。 } - (void)createThread2 { //创建线程后自动启动线程--这种是不能设置名字,是拿不到这个线程修改/设置属性; [NSThread detachNewThreadSelector:@selector(run:) toTarget:self withObject:@"rose"]; } - (void)createThread1 { // // 创建线程 // NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(run:) object:@"jack"];
//这种方法创建的线程是有名字的; // // 启动线程 // [thread start]; // 创建线程(使用自定义的) XMGThread *thread = [[XMGThread alloc] initWithTarget:self selector:@selector(run:) object:@"jack"];
调用 self 的 run:方法 传的参数 是 object:... thread.name = @"my-thread"; // 启动线程 [thread start]; } - (void)run:(NSString *)param { for (NSInteger i = 0; i<100; i++) { NSLog(@"-----run-----%@--%@", param, [NSThread currentThread]); }
[thread isMainThread] //类方法:判断线程是否是主线程;
} @end
自定义了一个Thread对象,继承了Thread
// // XMGThread.h // 03-掌握-NSThread #import <Foundation/Foundation.h> @interface XMGThread : NSThread @end
// XMGThread.m // 03-掌握-NSThread #import "XMGThread.h" @implementation XMGThread - (void)dealloc { NSLog(@"XMGThread -- dealloc"); } @end