如果连接了硬件键盘,则隐藏inputAccessoryView

Question

与此问题类似:iPad:检测外部键盘,我正在开发一个iPad应用程序,它使用带有自定义的文本字段inputAccessoryView来为虚拟键盘提供附加功能.

但是,如果硬件键盘(例如蓝牙键盘)连接到设备,则软件键盘未按预期显示,但由于某种原因,inputAccessoryView 仍在屏幕底部可见.此外,这似乎导致触发UIKeyboardDidShowNotification(并因此移动我的视图以避免键盘实际上不存在的遮挡),即使硬件键盘用于输入.

我找到了几种解决方案来检测是否连接了硬件键盘,但是所有这些解决方案都在接收到后检查状态UIKeyboardDidShowNotification,此时inputAccessoryView已经可见(例如,我如何检测iPad上是否有外接键盘？).

我正在寻找一种方法,如果没有连接硬件键盘,只显示inputAccessoryView.因此,我需要知道,如果一个硬件键盘连接之前,一个UIKeyboardDidShowNotification被解雇了.

此处提供的已接受解决方案如何检测iPad上是否存在外接键盘？对我来说没有选择,因为他们使用私有API可能会导致我的应用被拒绝.

Answer 1

这只是@arlomedia 答案的增强。我所做的就是观察 willShow 和 didShow。

我用 willShow 将文本视图移动到位，以便它以与键盘相同的速度移动。

我使用 didShow 使用上述技术检查键盘的外观大小，并相应地隐藏/显示accessoryInputView。

重要的是，我还将该视图设置为默认隐藏，并且当收到 willHide 事件时，它会再次隐藏。

- (void) addKeyboardObserver {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardHidden:) name:UIKeyboardWillHideNotification object:nil];
}

- (void) removeKeyboardObserver {
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}

- (void)keyboardWillShow:(NSNotification*)notification {
    CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    // If we're on iOS7 or earlier and landscape then the height is in the
    // width.
    //
    if ((IS_LANDSCAPE == YES) && (IS_IOS8_OR_LATER == NO)) {
        keyboardSize.height = keyboardSize.width;
    }

    NSNumber *rate = notification.userInfo[UIKeyboardAnimationDurationUserInfoKey];

    CGRect textFieldFrame = self.textField.frame;
    textFieldFrame.origin.y = ([Util screenHeight] - keyboardSize.height) - textFieldFrame.size.height - [Util scaledHeight:10.0];

    // Move the text field into place.
    //
    [UIView animateWithDuration:rate.floatValue animations:^{
        self.answerTextField.frame = textFieldFrame;
    }];

    keyboardShown = YES;
}

- (void)keyboardDidShow:(NSNotification*)notification {
    CGRect keyboardBeginFrame = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue];
    CGRect keyboardEndFrame = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGSize keyboardSize = keyboardBeginFrame.size;

    // If we're on iOS7 or earlier and landscape then the height is in the
    // width.
    //
    if ((IS_LANDSCAPE == YES) && (IS_IOS8_OR_LATER == NO)) {
        keyboardSize.height = ABS(keyboardBeginFrame.origin.x - keyboardEndFrame.origin.x); // the keyboard will move by an amount equal to its height when it appears; ABS is needed for upside-down orientations
    } else {
        keyboardSize.height = ABS(keyboardBeginFrame.origin.y - keyboardEndFrame.origin.y); // the keyboard will move by an amount equal to its height when it appears; ABS is needed for upside-down orientations
    }

    NSNumber *rate = notification.userInfo[UIKeyboardAnimationDurationUserInfoKey];

    [UIView animateWithDuration:rate.floatValue animations:^{
        if (keyboardSize.height <= self.accessoryBar.frame.size.height) {
            self.textField.inputAccessoryView.hidden = YES;
            self.answerTextField.inputAccessoryView.userInteractionEnabled = NO;
        } else {
            self.textField.inputAccessoryView.hidden = NO;
            self.answerTextField.inputAccessoryView.userInteractionEnabled = YES;
        }
    }];

    keyboardShown = YES;
}

- (void)keyboardHidden:(NSNotification*)notification {

    NSNumber *rate = notification.userInfo[UIKeyboardAnimationDurationUserInfoKey];

    // Remove/hide the accessory view so that next time the text field gets focus, if a hardware
    // keyboard is used, the accessory bar is not shown.
    //
    [UIView animateWithDuration:rate.floatValue animations:^{
        self.textField.inputAccessoryView.hidden = YES;
        self.answerTextField.inputAccessoryView.userInteractionEnabled = NO;
    }];

    keyboardShown = NO;
}

注意 编辑以添加对 userInteractionEnabled 的更改，以便隐藏的accessoryView不会吃水龙头。