弹出软键盘

commentEditText.requestFocus();
Timer timer = new Timer(); //设置定时器
timer.schedule(new TimerTask() {
    @Override
    public void run() { //弹出软键盘的代码
                    InputMethodManager imm = (InputMethodManager)mContext.getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.showSoftInput(commentEditText, InputMethodManager.RESULT_SHOWN);
    imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, InputMethodManager.HIDE_IMPLICIT_ONLY);
                }
            }, 500);

弹出软键盘之前，要保证EditText获取到焦点，并延迟执行，等待界面绘制完毕