ios - 在 NSOperationQueue 和 AFNetworking 中等待操作结束时显示 ActivityView

Question

我找到了一种方法来对 JSON 解析操作进行排队以等待完成数据解析，这是代码:

- (void)LoadParse { // this method is called by a UIButton

    NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:5.0];

    AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
        // PARSING SUCCESS CODE
        NSLog(@"operation completed"); <--- END OPERATION
        [self anotherMethod]; <--- CALL METHOD AFTER OPERATION IS FINISHED
    }
    failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON {
        // PARSING FAILURE CODE
    }];

    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    [queue addOperation:operation]; <--- START OPERATION

    // I NEED TO SHOW A SORT OF INDICATOR TO ADVERT USER THAT OPERATION ARE STILL LOADING
    // EXAMPLE: [DejalBezelActivityView activityViewForView:self.view withLabel:@"LOADING..."].showNetworkActivityIndicator = YES;

    [queue waitUntilAllOperationsAreFinished];

}

队列工作完美:应用程序等待解析操作结束，然后调用anotherMethod。但是我需要在仍有加载操作时显示一种 activityView 来广告用户:如你所见，我尝试将其添加到 addOperation 和 之间waitUntilAllOperationsAreFinished 但我看不到任何东西。这是正确的方法吗？那么，在哪里放置 ActivityView 代码以查看它直到所有操作都完成，或者使用其他方法来实现这一技巧？谢谢!

Answer 1

可以使用此代码

- (void)LoadParse { // this method is called by a UIButton

    NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:5.0];

    AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
        // PARSING SUCCESS CODE
    }
    failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON {
        // PARSING FAILURE CODE
    }];

    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    [queue addOperation:operation];

    UIActivityIndicatorView *tempSpinner = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    [self.view addSubview:tempSpinner]; 
    [tempSpinner startAnimating];

    [queue waitUntilAllOperationsAreFinished];

    [tempSpinner stopAnimating]; 
    //release tempSpinner if not using arc using [tempSpinner release];
    [self anotherMethod];
}