Question

我遇到了一个问题：我使用AFNetworking从服务器获取数据，我使用NSOperationQueue为它添加了许多操作，在每个请求中，我将此操作添加到队列中并使用waitUntilAllOperationsAreFinished如下：

request 1
...
    [queue addOperation:operation1];
    [queue waitUntilAllOperationsAreFinished];

request 2
...
    [queue addOperation:operation2];
    [queue waitUntilAllOperationsAreFinished];

我尝试了上面的代码，我的程序似乎挂起，之后，它运行正常。所以我想将MBProgressHUD添加到等待队列完成，然后我想检查队列是否完成，我想要隐藏MBProgressHUD。但是当我点击Button加载UIViewController时，MBProgressHUD无法显示。

HUD = [[MBProgressHUD alloc] initWithView:self.view];
[self.view addSubview:HUD];
HUD.delegate = self;
HUD.labelText = @"Loading";

实际上，我想在队列完成时显示MBProgressHUD。我怎样才能做到这一点？谢谢大家

Answer 1

很快就可以这样做：

[MBProgressHUD showHUDAddedTo:self.view animated:YES];
[MBProgressHUD hideHUDForView:self.view animated:YES];

检查MBProgressHUD的{{3}}

Answer 2

另一种更好的方法..

  HUD = [[MBProgressHUD alloc] initWithView:self.view];
    HUD.labelText = @"Doing funky stuff...";
    HUD.detailsLabelText = @"Just relax";
    HUD.mode = MBProgressHUDModeAnnularDeterminate;
    [self.view addSubview:HUD];

    [HUD showWhileExecuting:@selector(doSomeFunkyStuff) onTarget:self withObject:nil animated:YES];

和doSomeFunkyStuff

- (void)doSomeFunkyStuff {
    float progress = 0.0;

    while (progress < 1.0) {
        progress += 0.01;
        HUD.progress = progress;
        usleep(50000);
    }
}

详情 answer is here..

Answer 3

waitUntilAllOperationsAreFinished将阻塞当前线程，这可能是主线程，所以你真的不想这样做。

如果您正在使用AFNetworking，请在AFHTTPClient

上查看此方法

- (void)enqueueBatchOfHTTPRequestOperations:(NSArray *)operations 
                              progressBlock:(void (^)(NSUInteger numberOfFinishedOperations, NSUInteger totalNumberOfOperations))progressBlock 
                            completionBlock:(void (^)(NSArray *operations))completionBlock;

然后告诉你HUD然后调用这个方法并在completionBlock

中隐藏你的HUD

如何在iOS中添加MBProgressHUD等待加载数据

3 个答案: