Javascript Node.js-以太坊合约无法调用函数

我是区块链开发新手。为了了解目的，开始在Node.js中使用以太坊区块链概念开发小型合同

我已安装了包

“solc”：“^0.4.24”

和

“web3”：“^0.20.7”

，以在节点中生成和编译我的合同

My Grades.sol文件：

pragma solidity ^0.4.24;

contract Grades {
    mapping (bytes32 => string) public grades;
    bytes32[] public studentList;

    function Grades(bytes32[] studentNames) public {
        studentList = studentNames;
    }

    function giveGradeToStudent(bytes32 student, string grade) public {
        require(validStudent(student));
        grades[student] = grade;
    }

    function validStudent(bytes32 student) view public returns (bool) {
        for(uint i = 0; i < studentList.length; i++) {
            if (studentList[i] == student) {
                return true;
            }
        }
        return false;
    }

    function getGradeForStudent(bytes32 student) view public returns (string) {
        require(validStudent(student));
        return grades[student];
    }
}

我试图编译并运行我得到了异常

TypeError: deployedContract.giveGradeToStudent is not a function

在deployedContract中，我可以看到这些方法。有人能帮我吗

---

注意：我已安装了

“ganache cli”：“^6.1.8”

，用于添加事务并单独运行。我能够在ganache中看到交易。

我认为问题在于：

deployedContract = GradesContract.new(['John','James'],{data: byteCode, from: web3.eth.accounts[0], gas: 4700000});

.new（）

此处不会返回已部署的契约实例。（我不确定它是否会返回任何内容？）您需要回调，如下所示：

deployedContract = GradesContract.new(
  ['John', 'James'],
  {data: byteCode, from: web3.eth.accounts[0], gas: 4700000},
  function (err, instance) {
    if (instance.address) {
      instance.giveGradeToStudent(...);
    }
  }
);

deployedContract = GradesContract.new(
  ['John', 'James'],
  {data: byteCode, from: web3.eth.accounts[0], gas: 4700000},
  function (err, instance) {
    if (instance.address) {
      instance.giveGradeToStudent(...);
    }
  }
);