Android -- 监控软键盘的弹出和消失

一. 工具类

/**
 * 监控软键盘工具类
 */
public class KeyBoardShowListener {

    private Context ctx;

    public KeyBoardShowListener(Context ctx) {
        this.ctx = ctx;
    }
    OnKeyboardVisibilityListener keyboardListener;

    public OnKeyboardVisibilityListener getKeyboardListener() {
        return keyboardListener;
    }

    public interface OnKeyboardVisibilityListener {


        void onVisibilityChanged(boolean visible);
    }

    public void setKeyboardListener(final OnKeyboardVisibilityListener listener, Activity activity) {
        final View activityRootView = ((ViewGroup) activity.findViewById(android.R.id.content)).getChildAt(0);

        activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

            private boolean wasOpened;

            private final int DefaultKeyboardDP = 100;

            // From @nathanielwolf answer... Lollipop includes button bar in the root. Add height of button bar (48dp) to maxDiff
            private final int EstimatedKeyboardDP = DefaultKeyboardDP + (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ? 48 : 0);

            private final Rect r = new Rect();

            @Override
            public void onGlobalLayout() {
                // Convert the dp to pixels.
                int estimatedKeyboardHeight = (int) TypedValue
                        .applyDimension(TypedValue.COMPLEX_UNIT_DIP, EstimatedKeyboardDP, activityRootView.getResources().getDisplayMetrics());

                // Conclude whether the keyboard is shown or not.
                activityRootView.getWindowVisibleDisplayFrame(r);
                int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
                boolean isShown = heightDiff >= estimatedKeyboardHeight;

                if (isShown == wasOpened) {
                    Log.e("Keyboard state", "Ignoring global layout change...");
                    return;
                }

                wasOpened = isShown;
                listener.onVisibilityChanged(isShown);
            }
        });
    }
}

二. 调用

//监听软键盘的状态
new KeyBoardShowListener(getActivity()).setKeyboardListener(
        new KeyBoardShowListener.OnKeyboardVisibilityListener() {
            @Override
            public void onVisibilityChanged(boolean visible) {
                if (visible) {
                    //软键盘已弹出
                } else {
                    //软键盘未弹出
                }
            }
        }, getActivity());