键盘的弹出事件怎么监听呀

1、键盘显示则隐藏，没有显示则弹出

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);  
imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS);

2、通过判断高度来判断键盘状态

detailMainRL = (RelativeLayout) findViewById(R.id.home_news_detail_main_rl);
    detailMainRL.getViewTreeObserver().addOnGlobalLayoutListener(
      new OnGlobalLayoutListener(){
        @Override
        public void onGlobalLayout()
        {

          int heightDiff = detailMainRL.getRootView().getHeight() - detailMainRL.getHeight();
          Log.v(TAG, "detailMainRL.getRootView().getHeight() = " + detailMainRL.getRootView().getHeight());
          Log.v(TAG, "detailMainRL.getHeight() = " + detailMainRL.getHeight());

          if (heightDiff > 100)
          { // 说明键盘是弹出状态
            Log.v(TAG, "键盘弹出状态");
            commentBoxRL.setVisibility(View.VISIBLE);
          } else{
            Log.v(TAG, "键盘收起状态");
            commentBoxRL.setVisibility(View.GONE);
          }
        }
      });