UIButton disappears when my application returns from running in the background - objective-c

Question

I have a small project that contains a few UITextFields with a number keypad. When the keyboard is displayed I'm adding a button as a subview for the user to dismiss the keyboard.
However, if the keyboard is active and I close the application, the button I've added will disappear upon relaunching the app. (The app stays inactive, through multitasking, and therefore not quit completely.)
This is the code im using to add the button (my "done" button configured in the xib).
- (void)viewDidLoad
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(keyboardWillShow)name:UIKeyboardWillShowNotification object:nil];
[super viewDidLoad];
}
- (void)keyboardWillShow{
[[NSNotificationCenter defaultCenter] removeObserver:self];
// We must perform on delay (schedules on next run loop pass) for the keyboard subviews to be present.
[self performSelector:#selector(addHideKeyboardButtonToKeyboard) withObject:nil afterDelay:0];
}
- (void)addHideKeyboardButtonToKeyboard{
// Locate non-UIWindow.
doneButton.hidden=NO;
UIWindow *keyboardWindow = nil;
for (UIWindow *testWindow in [[UIApplication sharedApplication] windows]) {
if (![[testWindow class] isEqual:[UIWindow class]]) {
keyboardWindow = testWindow;
break;
}
}
if (!keyboardWindow) return;
// Locate UIKeyboard.
UIView *foundKeyboard = nil;
for (UIView __strong *possibleKeyboard in [keyboardWindow subviews]) {
// iOS 4 sticks the UIKeyboard inside a UIPeripheralHostView.
if ([[possibleKeyboard description] hasPrefix:#"<UIPeripheralHostView"]) {
possibleKeyboard = [[possibleKeyboard subviews] objectAtIndex:0];
}
if ([[possibleKeyboard description] hasPrefix:#"<UIKeyboard"]) {
foundKeyboard = possibleKeyboard;
break;
}
}
if (foundKeyboard) {
[doneButton setImage:[UIImage imageNamed:#"doneupHeb.png"] forState:UIControlStateNormal];
[doneButton setImage:[UIImage imageNamed:#"donedownHeb.png"] forState:UIControlStateHighlighted];
doneButton.frame = CGRectMake(-1, 163, 106, 53);
[foundKeyboard addSubview:doneButton];
// Add the button to foundKeyboard.
}
}
-(void)textFieldDidEndEditing:(UITextField *)textField{
[loan resignFirstResponder];
[YearCycle resignFirstResponder];
[prime resignFirstResponder];
[MothlyReturn resignFirstResponder];
[doneButton removeFromSuperview];
doneButton = nil;
}
- (void)textFieldDidBeginEditing:(UITextField *)textField{
textField.delegate=self;
//editingField = textField;
if ([prime isFirstResponder]||[MothlyReturn isFirstResponder]){
scroll.contentOffset = CGPointMake(0, 166 );
}
// if ([YearCycle isFirstResponder]){
// scroll.contentOffset = CGPointMake(0, 200);
}
- (IBAction)closeNumpad:(id)sender{
[loan resignFirstResponder];
[YearCycle resignFirstResponder];
[prime resignFirstResponder];
[MothlyReturn resignFirstResponder];
scroll.contentOffset = CGPointMake(0, 0);
doneButton.hidden=YES;
}

Answer 1

i fixed the problem with a little help from other questions in the website - for all of you that have or will have the problem - this is the code:
Please note: the button himself are designed in the xib file and not in the code.
the .h file:
BOOL firstTime;
BOOL add;
BOOL keyboardOpened;
IBOutlet UIButton *doneButton;
the .m file:
- (void)viewDidLoad
{
[super viewDidLoad];
firstTime = TRUE;
add = TRUE;
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil]; // Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
// [[NSNotificationCenter defaultCenter] removeObserver:self];
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
- (void)addButtonToKeyboard {
// create custom button
/* UIButton *doneButton = [UIButton buttonWithType:UIButtonTypeCustom];
doneButton.frame = CGRectMake(0, 163, 106, 53);
doneButton.adjustsImageWhenHighlighted = NO;
[doneButton setImage:[UIImage imageNamed:#"DoneUp.png"] forState:UIControlStateNormal];
[doneButton setImage:[UIImage imageNamed:#"DoneDown.png"] forState:UIControlStateHighlighted];
doneButton.tag = 3;
[doneButton addTarget:self action:#selector(doneButton:) forControlEvents:UIControlEventTouchUpInside];*/
// locate keyboard view
UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
UIView* keyboard;
for(int i=0; i<[tempWindow.subviews count]; i++) {
keyboard = [tempWindow.subviews objectAtIndex:i];
// keyboard found, add the button
if ([[keyboard description] hasPrefix:#"<UIPeripheralHostView"] == YES && add){
doneButton.frame = CGRectMake(-1, 163, 106, 53);
[keyboard addSubview:doneButton];
}
}
}
- (void)removeButtonFromKeyboard
{
// locate keyboard view
UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
UIView* keyboard;
for(int i=0; i<[tempWindow.subviews count]; i++) {
keyboard = [tempWindow.subviews objectAtIndex:i];
// keyboard found, remove the button
if([[keyboard description] hasPrefix:#"<UIPeripheralHost"] == YES) [[keyboard viewWithTag:3] removeFromSuperview];
}
}
- (IBAction)doneButton:(id)sender {
[loan resignFirstResponder];
[YearCycle resignFirstResponder];
[ageOfCeo resignFirstResponder];
[YearofBusiness resignFirstResponder];
scroll.contentOffset = CGPointMake(0, 0);
if (![[[UIDevice currentDevice] model] isEqualToString:#"iPad"] && ![[[UIDevice currentDevice] model] isEqualToString:#"iPad Simulator"])
{
[self removeButtonFromKeyboard];
firstTime = TRUE;
}
}
- (BOOL)textFieldShouldReturn:(UITextField *)theTextField {
[theTextField resignFirstResponder];
return YES;
}
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
if ([ageOfCeo isFirstResponder]||[YearofBusiness isFirstResponder]){
scroll.contentOffset = CGPointMake(0, 166 );
}
// firstResponder = textField;
}
- (void)keyboardDidShow:(id)sender
{
if (![[[UIDevice currentDevice] model] isEqualToString:#"iPad"] && ![[[UIDevice currentDevice] model] isEqualToString:#"iPad Simulator"])
{
NSLog(#"%#",[[UIDevice currentDevice] model]);
[self addButtonToKeyboard];
keyboardOpened = TRUE;
}
}
- (void)textFieldDidEndEditing:(UITextField *)textField
{
if (![[[UIDevice currentDevice] model] isEqualToString:#"iPad"] && ![[[UIDevice currentDevice] model] isEqualToString:#"iPad Simulator"])
{
[self removeButtonFromKeyboard];
keyboardOpened = FALSE;
}
}

Answer 2

i think your problem because you are removing the observer in the - (void)keyboardWillShow .. try to put this line [[NSNotificationCenter defaultCenter] removeObserver:self]; in the -(void)viewDidUnload