无法将类型“字符串”隐式转换为“ UnityEngine.UI.Text”

Question

控制台告诉我：

cannot implicitly convert type `string' to `UnityEngine.UI.Text'

我正在尝试做到这一点，以便在使用UI应用效果（单击“应用”按钮）时，我的“金额”下降。

int moneyamount;
int isApplied;

public Text moneyAmountText;
public Text effectPrice;

public Button buybutton;

// Use this for initialization
void Start () {
    moneyamount = PlayerPrefs.GetInt ("MoneyAmount");   
}

// Update is called once per frame
void Update () {

    moneyAmountText = "Money: " + moneyamount.ToString () + "$";

    isApplied = PlayerPrefs.GetInt ("isApplied");

    if (moneyamount >= 5 && isApplied == 0)
        buybutton.interactable = true;
    else
        buybutton.interactable = false;

}

public void applyeff()
{
    moneyamount -= 5;
    PlayerPrefs.SetInt ("isApplied", 1);
}