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Question

I am using a masterdetail app inside a tab bar controller. From one tab, i am collecting some data and using

tabBarController.selectedIndex=0;

This goes to the first tab which has the masterview controller. However, i have updated the database in my third tab and the table contents have to be updated in the master detail app of first tab. Effectively i need to call the

viewDidLoad

of the master detail app after setting the selected index. Could anyone say how to do this.

Answer 1

用新方法重写viewDidLoad的内容，然后在viewWillAppear上调用它们。

Answer 2

There are a few ways to accomplish this.

• Change your code in the 1st tab to update when your view appears instead of loads (recommended method)

• Call the view method of the controller to force the viewDidLoad if you have a reference to the controller.

   [self.localFundraiserController view]; 

• Use notifications. In your 3rd tab after the user has entered some data, send a notification. In your first tab, look for notifications and respond.

   //1st tab controller: -(void)viewDidLoad { [self loadUserData:nil] [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(loadUserData:) name:@"kUserEnteredData" object:nil]; } -(void)loadUserData:(NSNotification*)notification { id userData = notification.object; } //3rd tab controller when user entered data [[NSNotificationCenter defaultCenter] postNotificationName:@"kUserEnteredData" object:userData]; 

When posting the notification, you can pass object data which would be read in your loadUserData method. This is optional. The problem with notifications is that there is no guarantee that the view in your first tab is still loaded, so it may not be able to respond to the notification.