ios - 在 ViewController 之间传递布尔值

Question

我必须将一个布尔值从 ViewControllerA 传递给 ViewControllerB。在 ViewControllerA 我把作为一个属性：

 @property (nonatomic, assign)BOOL fromViewControllerA;

然后打开 ViewControllerB：

   ViewControllerB * viewControllerB = [[ViewControllerB alloc]initWithNibName:@"ViewControllerB" bundle:nil];

    self.fromRootViewController = YES;

    [self.navigationController pushViewController:viewControllerB animated:YES];

在 ViewControllerB 中，我导入了 ViewControllerA 并创建了属性：

   @property (nonatomic, strong) ViewControllerA *viewControllerA

稍后在 ViewDidLoad()

    if (viewController.fromViewController){
       //.......
    }

不起作用。为什么？

Answer 1

在 viewController B 中创建一个 BOOL 属性说.. BOOL setFlag；在 ViewController B 中合成它，

现在在执行推送的 ViewController A 中

 ViewControllerB * viewControllerB = [[ViewControllerB alloc]initWithNibName:@"ViewControllerB" bundle:nil];

    self.fromRootViewController = YES;
    viewControllerB.setFlag = YES;  //set the value here 

    [self.navigationController pushViewController:viewControllerB animated:YES];

Answer 2

是不是因为您应该将第二行修改为viewControllerB .fromRootViewController？（而不是自己）

Answer 3

如果您想知道视图控制器的来源，则不应使用属性。在您的导航控制器数组中使用基本导航（在您想知道推送来源的类中）。

NSArray *controllers = [self.navigationController viewControllers];
UIViewController *lastController = [controllers objectAtIndex:[controllers count]-2];
if([controller isKindOfClass:[YourDesireCheckController class]])
    return YES;
return NO;