c#事件委托 Text事件为什么不能触发呢？

public delegate void RoundChangeEventHandler();//委托

int turnNumber=0;

public event RoundChangeEventHandler ChangeEvent;//回合改变事件

///

    /// 回合变化

    /// </summary>

    void TurnChanged()

    {

        turnNumber++;

        listBox_fight.Items.Add(turnNumber);

        ChangeEvent?.Invoke();

    }

void TurnChangeEventHandle()

    {

        ChangeEvent += new RoundChangeEventHandler(Test);

    }

private void Test()

    {

        listBox_fight.Items.Add("Text事件触发");

        throw new NotImplementedException();

    }

TurnChangeEventHandle()这个方法你在哪里调用的？