Android完美检测键盘弹出/收起

代码很简单，可以直接复制粘贴。

原理请参照：http://blog.csdn.net/xiaole0313/article/details/51537809

    private void setListenerToRootView() {
        final View rootView = getWindow().getDecorView().findViewById(android.R.id.content);
        rootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                LogUtils.d(TAG, "[onGlobalLayout] .. in ..");
                boolean mKeyboardUp = isKeyboardShown(rootView);
                if (mKeyboardUp) {
                    LogUtils.d(TAG, "键盘弹出..");
                } else {
                    LogUtils.d(TAG, "键盘收起..");
                }
            }
        });
    }

    private boolean isKeyboardShown(View rootView) {
        final int softKeyboardHeight = 100;
        Rect r = new Rect();
        rootView.getWindowVisibleDisplayFrame(r);
        DisplayMetrics dm = rootView.getResources().getDisplayMetrics();
        int heightDiff = rootView.getBottom() - r.bottom;
        return heightDiff > softKeyboardHeight * dm.density;
    }