背景：在pushViewController之后把之前的vc刪掉

先上代碼

UIViewController *tempVC = [[UIViewController alloc] init];
[self.navigationController pushViewController:tempVC animated:YES];
NSMutableArray * subVCs = [NSMutableArray arrayWithArray:self.navigationController.viewControllers];
        for (int i=0; i<subVCs.count; i++) {
            if ([subVCs[i] isKindOfClass:[XXX class]]) {
                [subVCs removeObjectAtIndex:i];
            }
        }
        [self.navigationController setViewControllers:subVCs animated:YES];

大家一般都是這樣做，可是，但是，pushViewController執(zhí)行之后，有一定概率self.navigationController.viewControllers沒有你剛才push的vc，這就是坑，它不是立馬入棧的。

解決方法，很簡單

• 設(shè)置代理
  self.navigationController.delegate = self;
• 實現(xiàn)代理函數(shù)

NSMutableArray * subVCs = [NSMutableArray arrayWithArray:self.navigationController.viewControllers];
        for (int i=0; i<subVCs.count; i++) {
            if ([subVCs[i] isKindOfClass:[XXX class]]) {
                [subVCs removeObjectAtIndex:i];
            }
        }
        [self.navigationController setViewControllers:subVCs animated:YES];

嗯，是不是很簡單。