NSOperationQueue的基本使用

• NSOperationQueue的作用

　　　　NSOperation可以调用start方法来执行任务，但默认是同步执行的

　　　　如果将NSOperation添加到NSOperationQueue（操作队列）中，系统会自动异步执行NSOperation中的操作

　　

　　　　添加操作到NSOperationQueue中

　　　　- (void)addOperation:(NSOperation *)op;

　　　　- (void)addOperationWithBlock:(void (^)(void))block;

 -(void)blockOperation
 {
     //1.创建队列
     /*
      并发:全局并发队列,自己创建(concurrent)
      串行:主队列,自己创建(serial)
      */

     //    NSOperationQueue
     /*
      主队列:凡是放到主队列里面的任务都在主线程执行[NSOperationQueue mainQueue]
      非主队列:alloc int,同时具备了并发和串行的功能,默认是并发队列
      */

     NSOperationQueue *queue = [[NSOperationQueue alloc]init];

     //2.封装操作
     NSBlockOperation *op1 = [NSBlockOperation blockOperationWithBlock:^{
         NSLog(@"1----%@",[NSThread currentThread]);
     }];

     NSBlockOperation *op2 = [NSBlockOperation blockOperationWithBlock:^{
         NSLog(@"2----%@",[NSThread currentThread]);
     }];

     NSBlockOperation *op3 = [NSBlockOperation blockOperationWithBlock:^{
         NSLog(@"3----%@",[NSThread currentThread]);
     }];

     [op3 addExecutionBlock:^{
         NSLog(@"4----%@",[NSThread currentThread]);
     }];

     [op3 addExecutionBlock:^{
         NSLog(@"5----%@",[NSThread currentThread]);
     }];

     [op3 addExecutionBlock:^{
         NSLog(@"6----%@",[NSThread currentThread]);
     }];

     //3.添加操作到队列
     [queue addOperation:op1];   //[op1 start]
     [queue addOperation:op2];
     [queue addOperation:op3];

     //简便方法
     [queue addOperationWithBlock:^{
          NSLog(@"7----%@",[NSThread currentThread]);
     }];

     [queue addOperationWithBlock:^{
         NSLog(@"8----%@",[NSThread currentThread]);
     }];

 }
 -(void)invocation
 {
     //1.创建队列
     /*
      并发:全局并发队列,自己创建(concurrent)
      串行:主队列,自己创建(serial)
      */

     //    NSOperationQueue
     /*
      主队列:凡是放到主队列里面的任务都在主线程执行[NSOperationQueue mainQueue]
      非主队列:alloc int,同时具备了并发和串行的功能,默认是并发队列
      */

     NSOperationQueue *queue = [[NSOperationQueue alloc]init];

     //2.封装操作
     NSInvocationOperation *op1 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(download1) object:nil];

     NSInvocationOperation *op2 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(download2) object:nil];

     NSInvocationOperation *op3 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(download3) object:nil];

     //3.添加操作到队列
     [queue addOperation:op1];   //[op1 start]
     [queue addOperation:op2];
     [queue addOperation:op3];
 }

 -(void)download1
 {
     NSLog(@"download1---%@",[NSThread currentThread]);
 }

 -(void)download2
 {
     NSLog(@"download2---%@",[NSThread currentThread]);
 }

 -(void)download3
 {
     NSLog(@"download3---%@",[NSThread currentThread]);
 }

示例

　　把继承自NSOperation的类添加到Queue中:

-(void)custom
{
    //1.创建队列

    NSOperationQueue *queue = [[NSOperationQueue alloc]init];

    //2.封装操作
    YSOperation *op1 = [[YSOperation alloc]init];
    YSOperation *op2 = [[YSOperation alloc]init];

    //3.添加操作到队列
    [queue addOperation:op1];   //[op1 start]
    [queue addOperation:op2];
}

示例