There is a direct method to find this out. And, it does not require the layout changes. So it works in immersive fullscreen mode, too. But, unfortunately, it does not work on all devices. So you have to test it with your device(s). The trick is that you try to hide or show the soft keyboard and capture the result of that try. If it works correct then the keyboard is not really shown or hidden. We just ask for the state. To stay up-to-date, you simply repeat this operation, e.g. every 200 milliseconds, using a Handler. The implementation below does just a single check. If you do multiple checks, then you should enable all the (_keyboardVisible) tests.

public interface OnKeyboardShowHide
{
    void    onShowKeyboard( Object param );
    void    onHideKeyboard( Object param );
}

private static Handler      _keyboardHandler    = new Handler();
private boolean             _keyboardVisible    = false;
private OnKeyboardShowHide  _keyboardCallback;
private Object              _keyboardCallbackParam;

public void start( OnKeyboardShowHide callback, Object callbackParam )
{
    _keyboardCallback      = callback;
    _keyboardCallbackParam = callbackParam;
    //
    View view = getCurrentFocus();
    if (view != null)
    {
        InputMethodManager imm = (InputMethodManager) getSystemService( Activity.INPUT_METHOD_SERVICE );
        imm.hideSoftInputFromWindow( view.getWindowToken(), InputMethodManager.HIDE_IMPLICIT_ONLY, _keyboardResultReceiver );
        imm.showSoftInput( view, InputMethodManager.SHOW_IMPLICIT, _keyboardResultReceiver );
    }
    else // if (_keyboardVisible)
    {
        _keyboardVisible = false;
        _keyboardCallback.onHideKeyboard( _keyboardCallbackParam );
    }
}

private ResultReceiver      _keyboardResultReceiver = new ResultReceiver( _keyboardHandler )
{
    @Override
    protected void onReceiveResult( int resultCode, Bundle resultData )
    {
        switch (resultCode)
        {
            case InputMethodManager.RESULT_SHOWN :
            case InputMethodManager.RESULT_UNCHANGED_SHOWN :
                // if (!_keyboardVisible)
                {
                    _keyboardVisible = true;
                    _keyboardCallback.onShowKeyboard( _keyboardCallbackParam );
                }
                break;
            case InputMethodManager.RESULT_HIDDEN :
            case InputMethodManager.RESULT_UNCHANGED_HIDDEN :
                // if (_keyboardVisible)
                {
                    _keyboardVisible = false;
                    _keyboardCallback.onHideKeyboard( _keyboardCallbackParam );
                }
                break;
        }
    }
};

final View activityRootView = findViewById(R.id.rootlayout);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {

            Rect r = new Rect();
            activityRootView.getWindowVisibleDisplayFrame(r);

            int screenHeight = activityRootView.getRootView().getHeight();
            Log.e("screenHeight", String.valueOf(screenHeight));
            int heightDiff = screenHeight - (r.bottom - r.top);
            Log.e("heightDiff", String.valueOf(heightDiff));
            boolean visible = heightDiff > screenHeight / 3;
            Log.e("visible", String.valueOf(visible));
            if (visible) {
                Toast.makeText(LabRegister.this, "I am here 1", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(LabRegister.this, "I am here 2", Toast.LENGTH_SHORT).show();
            }
        }
});

我通过设置一个GlobalLayoutListener来做到这一点，如下所示:

final View activityRootView = findViewById(R.id.activityRoot);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(
        new OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                int heightView = activityRootView.getHeight();
                int widthView = activityRootView.getWidth();
                if (1.0 * widthView / heightView > 3) {
                    //Make changes for Keyboard not visible
                } else {
                    //Make changes for keyboard visible
                }
            }
        });

我把答案转换为kotlin，希望这对kotlin用户有帮助。

private fun checkKeyboardVisibility() {
    var isKeyboardShowing = false

    binding.coordinator.viewTreeObserver.addOnGlobalLayoutListener {
        val r = Rect()
        binding.coordinator.getWindowVisibleDisplayFrame(r)
        val screenHeight = binding.coordinator.rootView.height

        // r.bottom is the position above soft keypad or device button.
        // if keypad is shown, the r.bottom is smaller than that before.
        val keypadHeight = screenHeight - r.bottom


        if (keypadHeight > screenHeight * 0.15) { // 0.15 ratio is perhaps enough to determine keypad height.
            // keyboard is opened
            if (!isKeyboardShowing) {
                isKeyboardShowing = true

            }
        } else {
            // keyboard is closed
            if (isKeyboardShowing) {
                isKeyboardShowing = false

            }
        }
    }
}

谢谢大家的回答，我是根据自己的情况想出来的

/**
 * Add global layout listener to observe system keyboard visibility
 */
private void initObserverForSystemKeyboardVisibility() {
    getRootView().getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            //Add your own code here
            Log.d("TEST_CODE", "isSystemKeyboardVisible:" + isSystemKeyboardVisible())
        }
    });
}


/**
 * Check system keyboard visibility
 * @return true if visible
 */
public boolean isSystemKeyboardVisible() {
    try {
        final InputMethodManager manager = (InputMethodManager) getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
        final Method windowHeightMethod = InputMethodManager.class.getMethod("getInputMethodWindowVisibleHeight");
        final int height = (int) windowHeightMethod.invoke(manager);
        return height > 0;
    } catch (Exception e) {
        return false;
    }
}

可以使用showSoftInput()和hideSoftInput()的回调结果来检查键盘的状态。完整的细节和示例代码在

https://rogerkeays.com/how-to-check-if-the-software-keyboard-is-shown-in-android