iphone开发:如何设置另一个viewController的属性然后到达它

Question

让我们说我有两个viewcontrollers ViewControllerA,ViewControllerB当我按下按钮时,viewcontrollerA它正在推动viewControllerB.不过前推我想设置的属性viewControllerB的viewControllerA.但是nil当我检查变量时,我得到的只是值viewControllerB.我做的是;

在ViewControllerA:

VCB = [[ViewControllerB alloc]init];
[VCB setPropertyOfViewControllerB:someString];
NSLog(@"value: %@", VCB.PropertyOfViewControllerB); // Here I observe the correct value so I set successfully

但事情是我也希望从中获得它,viewControllerB但我得到nil变量.

在ViewControllerB:

//I already defined in h file as property
NSString *PropertyOfViewControllerB;
@property(nonatomic, retain) NSString *PropertyOfViewControllerB;

但是当我尝试检查ViewControllerB的viewDidLoad方法中的值时

NSLog(@"value: %@", PropertyOfViewControllerB);//here I get null not the value I set at viewControllerA

可能我想念一个我无法弄清楚的小点.任何帮助都是极好的.谢谢.

---

编辑:我正在使用故事板.我推送以下代码:

    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle: nil];
    lvc = [storyboard instantiateViewControllerWithIdentifier:@"mainManu"];
    [self.navigationController pushViewController:lvc animated:YES];

Answer 1

如果您使用VCB = [[ViewControllerB alloc]init];但通过Storyboard推送,那么VCB与Storyboard中使用的ViewController不同.试试这个:

 - (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
     if ([[segue identifier] isEqualToString:@"yourSegueName"]) {
         ViewControllerB *vc = [segue destinationViewController];
         [vc setPropertyOfViewControllerB:@"foo"];
     }  
}