CODEWITHSUNDEEP
iosxcodensnotificationcenter
lehn0058
lehn0058

Reputation: 20237

How do you handle keyboardDidShow on multiple views?

I have an app where I add a new item to a table view by having the user tap an edit button which shows a textfield cell at the bottom of the table, similar to the built in Notifications app. I need to adjust the table when the keyboard is shown so that it is not obstructed when their are many rows in the table. I am doing this by subscribing to the notification for when the keyboard shows:

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector (keyboardDidShow:)
                                                 name: UIKeyboardDidShowNotification
                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector (keyboardDidHide:)
                                                 name: UIKeyboardDidHideNotification
                                               object:nil];
}

...
...

-(void) keyboardDidShow: (NSNotification *)notif 
{
    // If keyboard is visible, return
    if (self.keyboardVisible) 
    {
        return;
    }

    // Get the size of the keyboard.
    NSDictionary* info = [notif userInfo];
    NSValue* aValue = [info objectForKey:UIKeyboardFrameBeginUserInfoKey];
    CGSize keyboardSize = [aValue CGRectValue].size;

    // Adjust the table view by the keyboards height.
    self.tableView.contentInset =  UIEdgeInsetsMake(0, 0, keyboardSize.height, 0);
    NSIndexPath *path = [NSIndexPath indexPathForRow:self.newsFeeds.count inSection:0];
    [self.tableView scrollToRowAtIndexPath:path atScrollPosition:UITableViewScrollPositionTop animated:YES];
    self.keyboardVisible = YES;
}

However, the table that I let a user add a row to can also be tapped and a new view is pushed on to the app. This view also has a text view and when the user taps in it and the keyboard shows the first viewcontroller still gets the notification, which causes a crash.

How can I either ignore the notification or get it to not fire when a new view is pushed?

Upvotes: 2

Views: 1841

Answers (1)

InsertWittyName
InsertWittyName

Reputation: 3940

You could add the class as an observer in viewDidAppear and remove it in viewWillDisappear.

Upvotes: 2

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