NSInvocationOperation和NSBlockOperation之间有什么区别

问题描述

Foundation Framework中有三个操作类（ NSOperation ， NSInvocationOperation 和 NSBlockOperation ）。

There are three operation classes in Foundation Framework(NSOperation, NSInvocationOperation and NSBlockOperation).

我已经阅读了但我不明白到底是什么这三个类之间的区别。请帮我。

I already read the concurrency programming guide but I did't understand exactly what is the difference between these three classes. Please help me.

推荐答案

表示一个块。 执行（或由target，selector，object定义的方法）。 必须是子类，它提供最大的灵活性但需要最多的代码。

NSBlockOperation exectues a block. NSInvocationOperation executes a NSInvocation (or a method defined by target, selector, object). NSOperation must be subclassed, it offers the most flexibility but requires the most code.

NSBlockOperation和NSInvocationOperation都是NSOperation的子类。它们由系统提供，因此您无需为简单任务创建新的子类。

NSBlockOperation and NSInvocationOperation are both subclasses of NSOperation. They are provided by the system so you don't have to create a new subclass for simple tasks.

对于大多数任务，使用NSBlockOperation和NSInvocationOperation应该足够了。

Using NSBlockOperation and NSInvocationOperation should be enough for most tasks.

这是一个使用所有三个完全相同的代码示例：

Here is a code example for the use of all three that do exactly the same thing:

// For NSOperation subclass
@interface SayHelloOperation : NSOperation
@end

@implementation SayHelloOperation

- (void)main {
    NSLog(@"Hello World");
}

@end

// For NSInvocationOperation
- (void)sayHello {
    NSLog(@"Hello World");
}


- (void)startBlocks {
    NSBlockOperation *blockOP = [NSBlockOperation blockOperationWithBlock:^{
        NSLog(@"Hello World");
    }];
    NSInvocationOperation *invocationOP = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(sayHello) object:nil];
    SayHelloOperation *operation = [[SayHelloOperation alloc] init];

    NSOperationQueue *q = [[NSOperationQueue alloc] init];
    [q addOperation:blockOP];
    [q addOperation:invocationOP];
    [q addOperation:operation];
}

这篇关于NSInvocationOperation和NSBlockOperation之间有什么区别的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！