[摘要]本文是對多線程的簡單使用的講解，對學習IOS蘋果軟件開發有所幫助,與大家分享。

NSOperationQueue的簡單使用過程：

1. 建立一個NSOperationQueue的對象

2. 建立一個NSOperation的對象

3. 將operation加入到NSOperationQueue中

MRC 需要手動釋放

4. release掉operation

NSOperationQueue *queue = [NSOperationQueue new];

NSInvocationOperation *operation = [[NSInvocationOperation alloc]

initWithTarget:self

selector:nil)

object:nil];

[queue addOperation:operation];

/***********************************GCD**************************************************/

//一次性執行

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

//code be executed once

});

//延遲調用

double delayInSeconds = 2.0;

dispatch_time_t timer = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds *NSEC_PER_SEC);

dispatch_after(timer, dispatch_get_main_queue(), ^{

//code be executed once after delay

});

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{

　//code be executed once after delay

});

//自定義queque

dispatch_queue_t fun = dispatch_queue_create("funfun", NULL);

dispatch_async(fun, ^{

// your code

});

MRC 需要釋放

//dispatch_release(fun);

//GCD組 同時進行多個任務，任務完成之後再主線程執行其他任務

dispatch_group_t group = dispatch_group_create();

dispatch_group_async(group, dispatch_get_global_queue(0, 0), ^{

//your code

});

dispatch_group_async(group, dispatch_get_global_queue(0, 0), ^{

//your code

});

dispatch_group_notify(group, dispatch_get_main_queue(), ^{

//your code

});

//多線程的線程安全

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); dispatch_async(queue, ^{ 　　// 線程鎖 NSLock *lock = [[NSLock alloc] init];

[lock lock];

//your code

[lock unlock];

}); dispatch_async(queue, ^{ NSLock *lock = [[NSLock alloc] init];

[lock lock];

//your code

[lock unlock];

});