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)
            }
        }
    }
});

@iWantScala的回答很棒，但不适合我 rootView.getRootView().getHeight()总是有相同的值

一种方法是定义两个变量

private int maxRootViewHeight = 0;
private int currentRootViewHeight = 0;

添加全局监听器

rootView.getViewTreeObserver()
    .addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            currentRootViewHeight = rootView.getHeight();
            if (currentRootViewHeight > maxRootViewHeight) {
                maxRootViewHeight = currentRootViewHeight;
            }
        }
    });

然后检查

if (currentRootViewHeight >= maxRootViewHeight) {
    // Keyboard is hidden
} else {
    // Keyboard is shown
}

工作正常

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

如你所知，android软件的键盘只有在有可能的输入事件时才可见。换句话说，只有当EditText被聚焦时，键盘才可见。这意味着你可以通过使用OnFocusChangeListener获得键盘是否可见。

//Declare this Globally

public boolean isKeyBoardVisible = false;

//In OnCreate *[For Activity]*, OnCreateView *[For Fragment]*

text_send.setOnFocusChangeListener(new View.OnFocusChangeListener() {

    @Override
    public void onFocusChange(View v, boolean hasFocus) {
        if(hasFocus)
            isKeyBoardVisible = true;
        else
            isKeyBoardVisible = false;
    }
});

现在你可以在类的任何地方使用isKeyBoardVisible变量来获取键盘是否打开。这对我来说很有效。

注意:当使用InputMethodManager以编程方式打开键盘时，这个过程不起作用，因为它不调用OnFocusChangeListener。

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;
    }
}

这应该工作，如果你需要检查键盘状态:

fun Activity.isKeyboardOpened(): Boolean {
    val r = Rect()

    val activityRoot = getActivityRoot()
    val visibleThreshold = dip(UiUtils.KEYBOARD_VISIBLE_THRESHOLD_DP)

    activityRoot.getWindowVisibleDisplayFrame(r)

    val heightDiff = activityRoot.rootView.height - r.height()

    return heightDiff > visibleThreshold;
}

fun Activity.getActivityRoot(): View {
    return (findViewById<ViewGroup>(android.R.id.content)).getChildAt(0);
}

UiUtils的地方。KEYBOARD_VISIBLE_THRESHOLD_DP = 100, dip()是一个anko函数，转换dpToPx:

fun dip(value: Int): Int {
    return (value * Resources.getSystem().displayMetrics.density).toInt()
}