你可以试试这个，对我来说很管用:

InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);

if (imm.isAcceptingText()) {
    //Software Keyboard was shown..
} else {
    //Software Keyboard was not shown..
}

这段代码工作得很好

根视图使用这个类:

public class KeyboardConstraintLayout extends ConstraintLayout {

private KeyboardListener keyboardListener;
private EditText targetEditText;
private int minKeyboardHeight;
private boolean isShow;

public KeyboardConstraintLayout(Context context) {
    super(context);
    minKeyboardHeight = getResources().getDimensionPixelSize(R.dimen.keyboard_min_height);
}

public KeyboardConstraintLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
    minKeyboardHeight = getResources().getDimensionPixelSize(R.dimen.keyboard_min_height);
}

public KeyboardConstraintLayout(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    minKeyboardHeight = getResources().getDimensionPixelSize(R.dimen.keyboard_min_height);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    if (!isInEditMode()) {
        Activity activity = (Activity) getContext();
        @SuppressLint("DrawAllocation")
        Rect rect = new Rect();
        getWindowVisibleDisplayFrame(rect);

        int statusBarHeight = rect.top;
        int keyboardHeight = activity.getWindowManager().getDefaultDisplay().getHeight() - (rect.bottom - rect.top) - statusBarHeight;

        if (keyboardListener != null && targetEditText != null && targetEditText.isFocused()) {
            if (keyboardHeight > minKeyboardHeight) {
                if (!isShow) {
                    isShow = true;
                    keyboardListener.onKeyboardVisibility(true);
                }
            }else {
                if (isShow) {
                    isShow = false;
                    keyboardListener.onKeyboardVisibility(false);
                }
            }
        }
    }
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

public boolean isShowKeyboard() {
    return isShow;
}

public void setKeyboardListener(EditText targetEditText, KeyboardListener keyboardListener) {
    this.targetEditText = targetEditText;
    this.keyboardListener = keyboardListener;
}

public interface KeyboardListener {
    void onKeyboardVisibility (boolean isVisible);
}

}

在activity或fragment中设置键盘监听器:

    rootLayout.setKeyboardListener(targetEditText, new KeyboardConstraintLayout.KeyboardListener() {
    @Override
    public void onKeyboardVisibility(boolean isVisible) {

    }
});

这是我的解决方案，它很有效。而不是寻找像素大小，只是检查内容视图的高度是否改变:

// Scroll to the latest comment whenever the keyboard is shown
commentsContent.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

        private int oldHeight;

        @Override
        public void onGlobalLayout() {
            int newHeight = commentsContent.getMeasuredHeight();
            if (newHeight < oldHeight) {
                // Check for the keyboard showing in case the height difference
                // is a result of orientation change
                if (isSoftKeyboardShowing(CommentsActivity.this)) {
                    // Keyboard is showing so scroll to the latest comment
                    scrollToLatestComment();
                }
            }
            oldHeight = newHeight;
        }

    });


public static boolean isSoftKeyboardShowing(Activity activity) {
    InputMethodManager inputMethodManager = (InputMethodManager) activity.getSystemService(Activity.INPUT_METHOD_SERVICE);
    return inputMethodManager.isActive();
}

Reuben Scratton和Kachi提供的解决方案似乎依赖于设备的像素密度，如果你有一个高密度的设备，即使按下键盘，高度差也可能超过100。围绕这一点的工作将是看到初始高度差(键盘向下)，然后与当前的差异进行比较。

boolean isOpened = false;
int firstHeightDiff = -1;

public void setListenerToRootView(){
    final View activityRootView = getActivity().getWindow().getDecorView().findViewById(android.R.id.content);
    Rect r = new Rect();
    activityRootView.getWindowVisibleDisplayFrame(r);
    firstHeightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
    activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            if (isAdded()) {
                Rect r = new Rect();
                activityRootView.getWindowVisibleDisplayFrame(r);
                int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
                isOpened = heightDiff>firstHeightDiff+100;
                if (isAdded())
                    if(isOpened) {
                        //TODO stuff for when it is up
                    } else {
                        //TODO stuf for when it is down
                    }
            }
        }
    });
}

我使用了与鲁班的答案略有不同的答案，事实证明在某些情况下更有帮助，特别是在使用高分辨率设备时。

final View activityRootView = findViewById(android.R.id.content);
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
                }
            }
        });

这个解决方案可能会重新打开键盘，但它是有效的。

InputMethodManager inputManager = ( (InputMethodManager) this.getSystemService(Context.INPUT_METHOD_SERVICE) );

private boolean isKeyboardShowing() {

    boolean isKeyboardShowing = inputManager.hideSoftInputFromWindow(irrelevantView.getWindowToken(), 0);
    if (isKeyboardShowing) {
        inputManager.showSoftInput(this.getCurrentFocus(), 0);
    }
    return isKeyboardShowing;
}