keyboard not show at first time(iOS) - ios

Question

My code like this:
- (void)setupSubViews {
[self addSubview:self.textView];
[self addSubview:self.sendButton];
[self.textView mas_makeConstraints:^(MASConstraintMaker *make) {
make.top.equalTo(5);
make.bottom.equalTo(-5);
make.leading.equalTo(9);
}];
[self.sendButton mas_makeConstraints:^(MASConstraintMaker *make) {
make.centerY.equalTo(self);
make.trailing.equalTo(-9);
make.leading.equalTo(self.textView.mas_trailing).offset(7);
make.width.equalTo(60);
make.height.equalTo(40);
}];
}
The show function to make the textView becomeFirstResponder
- (void)show {
UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
[keyWindow addSubview:self];
[self mas_makeConstraints:^(MASConstraintMaker *make) {
make.leading.trailing.equalTo(0);
make.bottom.equalTo(InputHeight);
}];
[self.textView becomeFirstResponder];
}
This view add to the keyWindow at the bottom of mainScreen, it's translate will changing follow the keyboard when the keyboard's frame changed.
- (void)keyboardWillChangeFrame:(NSNotification *)noti {
if (!self.textView.isFirstResponder) {
return;
}
NSValue *endFrame = noti.userInfo[#"UIKeyboardFrameEndUserInfoKey"];
CGFloat endY = [endFrame CGRectValue].origin.y;
BOOL isBackToBottom = endY == UI_SCREEN_HEIGHT;
CGFloat needOffset = endY - (UI_SCREEN_HEIGHT + InputHeight);
if (isBackToBottom) {
[UIView animateWithDuration:0.25 animations:^{
self.transform = CGAffineTransformIdentity;
} completion:^(BOOL finished) {
[self removeFromSuperview];
}];
} else {
[UIView animateWithDuration:0.25 animations:^{
self.transform = CGAffineTransformMakeTranslation(0, needOffset);
}];
}
}
Use Case:
viewController has a button, button click action like this:
- (void)beginChat {
[self.inputView show];
}
self.inputView is the above customView,
- (LiveChatInputView *)inputView {
if (!_inputView) {
_inputView = [LiveChatInputView new];
_inputView.sendBlock = ^(NSString *string) {
....
};
}
return _inputView;
}
Now my question is that when we call show function at the first time after application launched, the keyboard will not show, but call show function in second time, every thing is fine.
How to deal with this question, THX.

Answer 1

Calling this method is not a guarantee that the object will become the first responder.
As per Apple,
A responder object only becomes the first responder if the current
responder can resign first-responder status (canResignFirstResponder)
and the new responder can become first responder.
Try calling becomeFirstResponder like below,
[self.textView performSelector:#selector(becomeFirstResponder) withObject:nil afterDelay:0];

Answer 2

I made a mistake, call [self removeFromSuperview] in the function of keyboardWillChangeFrame:.
I thought UIKeyboardWillChangeFrameNotification could only post it once at the keyboard show or hide, so i put the implementation of back action in keyboardWillChangeFrame:, and controlled by endFrame.origin.y == UI_SCREEN_HEIGHT
In practice, the fact is that:
when the keyboard show, NSNotificationCenter will post UIKeyboardWillChangeFrameNotification three times:
first
second
third
Tips:
only first time show the keyboard after application launched, the first UIKeyboardWillChangeFrameNotification of above three, the endFrame.origin.y is equal to UI_SCREEN_HEIGHT
My solution:
Observer the UIKeyboardWillHideNotification, and do back action in this callback.
Thanks for all answers of this question.