如何在iOS中的不同視圖控制器之間傳遞變量

Question

我嘗試此代碼，但它對我無效。 謝謝

-(void)passvar:(NSString *)user 
{ 
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; 
UIViewController *viewController = (UIViewController *)[storyboard instantiateViewControllerWithIdentifier:@"signupvc"]; 

viewController.user = user; 

[self presentViewController:viewController animated:YES completion:nil]; 

} 

Answer 1

UIViewController不具有user財產。 你應該用你的自定義子類，而不是UIVIewController

-(void)passvar:(NSString *)user 
{ 
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; 
MyCustomViewController *viewController = (MyCustomViewController *)[storyboard instantiateViewControllerWithIdentifier:@"signupvc"]; 

viewController.user = user; 

[self presentViewController:viewController animated:YES completion:nil]; 

} 

注意，在這個代碼，你從故事板實例化一個新的MyCustomViewController，並提交給用戶。它與調用這些代碼行之前打開的任何其他View Controller無關。
如果您調用此函數3次，它將打開3個不同的MyCustomViewController。