ios - 在 block 内推送 View Controller 不起作用

Question

在完成 block 中触发方法的正确方法是什么(如果推荐的话)？现在，我有一个 IBAction 调用一个方法来下载信息，完成 block 表示信息是否成功检索。如果是的话，我想推送一个显示该信息的 View Controller ，但目前什么也没有发生。我猜它与主线程、gcd 等有关...

__weak YTTMSetupViewController *weakSelf = self;
    [mc downloadJson:^(BOOL success) {
            if(success){
                NSLog(@"sucess. metric count - %i",(int)mc.collection.count);

                //info was downloaded. Push new view controller with info
                YTTMMetricTableViewController *mtvc = [self.storyboard instantiateViewControllerWithIdentifier:@"YTTMMetricTableViewController"];
                mtvc.group = (WAGroup*)[[WAMetricCollection sharedInstance].collection lastObject];
                mtvc.hidesBottomBarWhenPushed = YES;
                [weakSelf.navigationController pushViewController:mtvc animated:YES];
            }
            else{
                NSLog(@"failure");
                //display failure UI
            }
            NSLog(@"end of downloading");
            [HUD dismissAfterDelay:0.5f animated:YES];
        }];

Answer 1

不确定这是否是正确的方法，但它奏效了。

我添加了一个将 vc 推送到主线程的方法:

        [weakSelf performSelectorOnMainThread:@selector(pushDetail) withObject:nil waitUntilDone:YES];

完成的代码:

__weak YTTMSetupViewController *weakSelf = self;
    [mc downloadJson:^(BOOL success) {
            if(success){
                NSLog(@"sucess. metric count - %i",(int)mc.collection.count);

                //info was downloaded. Push new view controller with info
                [weakSelf performSelectorOnMainThread:@selector(pushDetail) withObject:nil waitUntilDone:YES];
            }
            else{
                NSLog(@"failure");
                //display failure UI
            }
            NSLog(@"end of downloading");            
        }];

}

-(void)pushDetail{
    __weak YTTMSetupViewController *weakSelf = self;
    YTTMMetricTableViewController *mtvc = [self.storyboard instantiateViewControllerWithIdentifier:@"YTTMMetricTableViewController"];
    mtvc.group = (WAGroup*)[[WAMetricCollection sharedInstance].collection lastObject];
    mtvc.hidesBottomBarWhenPushed = YES;
    [weakSelf.navigationController pushViewController:mtvc animated:YES];

}