Ios 在appdelegate中从viewcontroller调用方法不会更改屏幕上的文本

每次启动应用程序时，我都想更改屏幕上的文本。已调用该方法，但文本不变

myAppDelegate.m

- (void)applicationDidBecomeActive:(UIApplication *)application
{

    [[UIApplication sharedApplication] setApplicationIconBadgeNumber:-1];
    viewController *object = [[viewController alloc] init];
    [object methodA];
}

viewController.m

-(void)methodA{
    //Create an URL pointing to your plist
    NSURL *plistURL = [[NSBundle mainBundle] URLForResource: @"myPlist" withExtension: @"plist"];
    //Read the plist from the application bundle into an array object.
    NSArray *stringsArray = [NSArray arrayWithContentsOfURL: plistURL];
    //Create a random index into the array
    NSUInteger randomIndex = arc4random_uniform(stringsArray.count);
    //Fetch the string at that random index
    NSString *randomString = stringsArray[randomIndex];
    //Set some label's text to the random string.
    _myLabel.text = randomString;
    NSLog(@"methodA");

}

我的日志中有“methodA”。

请尝试以下代码：

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle: nil];
yourViewController *object = [storyboard instantiateViewControllerWithIdentifier:@"id"];
[object methodA];

---

将

MainStoryboard

替换为情节提要名称，将

id

替换为视图控制器id。您可以在情节提要中设置id。最后用视图控制器替换

您的viewController

。

您正在使用情节串连板吗？您正在创建

viewController

的新实例。不要那样做。获取对现有视图控制器的引用。@ArdaKeskiner是否使用情节提要？@ArdaKeskiner是否将“MainstryBoard”替换为情节提要名称？