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

这对我很有用。也许这对于所有版本来说都是最好的方法。

这将是有效的，使键盘可见性的属性，并观察这个变化延迟，因为onGlobalLayout方法调用多次。此外，检查设备旋转和windowSoftInputMode是否为adjustNothing也很好。

boolean isKeyboardShowing = false;
void onKeyboardVisibilityChanged(boolean opened) {
    print("keyboard " + opened);
}

// ContentView is the root view of the layout of this activity/fragment    
contentView.getViewTreeObserver().addOnGlobalLayoutListener(
    new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {

        Rect r = new Rect();
        contentView.getWindowVisibleDisplayFrame(r);
        int screenHeight = contentView.getRootView().getHeight();

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

        Log.d(TAG, "keypadHeight = " + keypadHeight);

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

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;
        }
    }
};

我是这样做的，但只有当你的目标是关闭/打开键盘时，它才有意义。

关闭示例:(检查键盘是否已经关闭，如果没有关闭)

imm.showSoftInput(etSearch, InputMethodManager.HIDE_IMPLICIT_ONLY, new ResultReceiver(null) {
                    @Override
                    protected void onReceiveResult(int resultCode, Bundle resultData) {
                        super.onReceiveResult(resultCode, resultData);
                        if (resultCode != InputMethodManager.RESULT_UNCHANGED_HIDDEN)
                            imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
                    }
                });

试试这段代码，它真的工作，如果keyboardshow是显示的，那么这个函数返回真值....

private final String TAG = "TextEditor";
private TextView mTextEditor;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_editor);
    mTextEditor = (TextView) findViewById(R.id.text_editor);
    mTextEditor.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            isKeyboardShown(mTextEditor.getRootView());
        }
    });
}

private boolean isKeyboardShown(View rootView) {
    /* 128dp = 32dp * 4, minimum button height 32dp and generic 4 rows soft keyboard */
    final int SOFT_KEYBOARD_HEIGHT_DP_THRESHOLD = 128;

    Rect r = new Rect();
    rootView.getWindowVisibleDisplayFrame(r);
    DisplayMetrics dm = rootView.getResources().getDisplayMetrics();
    /* heightDiff = rootView height - status bar height (r.top) - visible frame height (r.bottom - r.top) */
    int heightDiff = rootView.getBottom() - r.bottom;
    /* Threshold size: dp to pixels, multiply with display density */
    boolean isKeyboardShown = heightDiff > SOFT_KEYBOARD_HEIGHT_DP_THRESHOLD * dm.density;

    Log.d(TAG, "isKeyboardShown ? " + isKeyboardShown + ", heightDiff:" + heightDiff + ", density:" + dm.density
            + "root view height:" + rootView.getHeight() + ", rect:" + r);

    return isKeyboardShown;
}