Question

我的代码中有3个功能。我为管理队列执行函数所做的代码。

 [self firstMethodWithOnComplete:^{
    [self SecongMethodWithOnComplete:^{
        dispatch_async(dispatch_get_main_queue(), ^{
            [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(CallThirdMethod) userInfo:nil repeats:NO];
            });
    }];
}];

第一和第二功能

- (void)firstMethodWithOnComplete:(void (^)(void))onComplete {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
    //processing here.....

    [self CallFirstMethod];
    onComplete();
});
 }

- (void)SecongMethodWithOnComplete:(void (^)(void))onComplete {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
    //processing here.....
    [self CallSecondMethod];
    onComplete();
});
 }

问题是我无法管理他们的执行。我想要执行顺序，第二个函数只有在第一个结束时执行，第三个执行，如果第二个执行结束。请帮我解决这个问题或给出任何适当的建议。

Answer 1

您可以将调度组用于此类要求，下面我发布了我使用的示例代码

__block NSError *configError = nil;
__block NSError *preferenceError = nil;

// Create the dispatch group
dispatch_group_t serviceGroup = dispatch_group_create();


dispatch_group_enter(serviceGroup);
 // Start the first async service
dispatch_group_leave(serviceGroup);


dispatch_group_enter(serviceGroup);
// Start the second  async service
dispatch_group_leave(serviceGroup);

dispatch_group_notify(serviceGroup,dispatch_get_main_queue(),^{
    //Update UI in this block of code
});

第一次功能完成后如何调用第二功能？

1 个答案: