NSOperation-1

NSOperation的作用

配合使用NSOperation和NSOperationQueue也能实现多线程编程

NSOperation和NSOperationQueue也能实现多线程编程

NSOperation和NSOperationQueue实现多线程的具体步骤

先将需要执行的操作封装到一个NSOperation对象中

然后将NSOperation对象添加到NSOperationQueue中

系统会自动将NSOperationQueue中的NSOperation取出来

将取出的NSOperation封装的操作放到一条线程中执行

NSOperation的子类

NSOperation是个抽象类，并不具备封装操作的能力，必须使用它的子类

使用NSOperation子类的方式有3种

NSInvocationOperation

NSBlockOperation

自定义子类继承NSOperation,实现内部相应的方法

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

}

-(void)blockOperation{

NSBlockOperation *op  = [NSBlockOperation blockOperationWithBlock:^{

//在主线程

NSLog(@"下载1======%@",[NSThread currentThread]);
}];

//在子线程

[op addExecutionBlock:^{

NSLog(@"下载2======%@",[NSThread currentThread]);

}];

[op addExecutionBlock:^{

NSLog(@"下载3======%@",[NSThread currentThread]);

}];

[op addExecutionBlock:^{

NSLog(@"下载4======%@",[NSThread currentThread]);

}];

[op start];

}

-(void)invocationOperation{

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

[op start];

}

-(void)run{

NSLog(@"----%@"，[NSThread currentThread]);

}