1

我在外部文件中有一个类，我将其导入。该类被实例化为导入下方的 3 个对象。

我运行函数调用初始，我调用方法将 mystudent0 的属性更改为不存在。然后返回所有属性，一切都按预期运行。

问题是当我运行其他函数来调用其他类方法时，对象会被初始化。到初始值。

我不知道如何停止重新初始化，所以我可以调用其他方法。

代码：

import { storage, context, PersistentVector } from "near-sdk-as";
import { Student } from "./student";

let students = new PersistentVector<string>('student');
let currstudents = new PersistentVector<Student>('studentlist');
let mystudent0 = new Student(1,"Pete Gillan", true);
let mystudent1 = new Student(2,"John Reager", true);
let mystudent2 = new Student(3,"Mary Smith", false);

//
export function initial(): string{
        //
        let strStud1: string;
        let strStud2: string;
        let strStud3: string;
        let studentCounter: i32 = 0;
        let len: i32;
        currstudents.push(mystudent0);
        currstudents.push(mystudent1);
        currstudents.push(mystudent2);
        mystudent0.set_absent();
        strStud1 = " Student num " + mystudent0.get_studnum().toString() + " Student name: " + mystudent0.get_sname() + " present: " + mystudent0.get_present().toString() + '\n';
        strStud2 = "Student num " + mystudent1.get_studnum().toString() + " Student name: " + mystudent1.get_sname() +  " present: " + mystudent1.get_present().toString() + '\n';
        strStud3 = "Student num " + mystudent2.get_studnum().toString() + " Student name: " + mystudent2.get_sname() +  " present: " + mystudent2.get_present().toString() + '\n';
        len = currstudents.length;
        return strStud1 + strStud2 + strStud3 + " " + len.toString();
}

export function absent(): string{
    mystudent0.set_absent();
    return "absent";
}


//
export function welcomeUser(): string {
    return "Greetings " + context.sender + " .... :)"
}

export function get_name(): string{
    //let mystudent0 = new Student(1,"Pete Gillan", true);
    let strStud1: string;
    let strStud2: string;
    let strStud3: string;
    let len: i32;
    strStud1 = " Student num " + mystudent0.get_studnum().toString() + " Student name: " + mystudent0.get_sname() + " present: " + mystudent0.get_present().toString() + '\n';
    strStud2 = "Student num " + mystudent1.get_studnum().toString() + " Student name: " + mystudent1.get_sname() +  " present: " + mystudent1.get_present().toString() + '\n';
    strStud3 = "Student num " + mystudent2.get_studnum().toString() + " Student name: " + mystudent2.get_sname() +  " present: " + mystudent2.get_present().toString() + '\n';
    len = currstudents.length;
    return strStud1 + strStud2 + strStud3 + " " + len.toString();
}

结果：

:~/roster-project/src/simple/assembly$ near call $CONTRACT initial --account_id $OWNER
Scheduling a call: dev-1640024016985-13984676030210.initial()
Doing account.functionCall()
Transaction Id CFhBKtxJZFt97kFNfRAE3EoXc9tvPqb6rgPMdv1atfjN
To see the transaction in the transaction explorer, please open this url in your browser
https://explorer.testnet.near.org/transactions/CFhBKtxJZFt97kFNfRAE3EoXc9tvPqb6rgPMdv1atfjN
' Student num 1 Student name: Pete Gillan present: **false**\n' +
  'Student num 2 Student name: John Reager present: true\n' +
  'Student num 3 Student name: Mary Smith present: false\n' +
  ' 6'
:~/roster-project/src/simple/assembly$  near call $CONTRACT get_name --account_id $OWNER
Scheduling a call: dev-1640024016985-13984676030210.get_name()
Doing account.functionCall()
Transaction Id 8485qqoHSp9WrjiNQKVZtzwMZsh1tE29WFwRkzfJwYLL
To see the transaction in the transaction explorer, please open this url in your browser
https://explorer.testnet.near.org/transactions/8485qqoHSp9WrjiNQKVZtzwMZsh1tE29WFwRkzfJwYLL
' Student num 1 Student name: Pete Gillan present: **true**\n' +
  'Student num 2 Student name: John Reager present: true\n' +
  'Student num 3 Student name: Mary Smith present: false\n' +
  ' 6'
:~/roster-project/src/simple/assembly$

班级：

import { logging, RNG } from "near-sdk-as";

//@nearBindgen
export class Student {

        private studnum: i32
        private sname: string;
        private present: boolean;

        constructor (studnum: i32, sname: string, present: boolean) {
            //studnum = this.studnum;
            //sname = this.sname;
            //present = this.present;

            this.sname = sname;
            this.studnum = studnum;
            this.present = present;

        }

        set_studnum(): void {
            this.studnum = studnum;
        }

        set_name(): void {

            this.sname = same;
        }

        set_present(): void {
            this.present = true;
        }

        set_absent(): void {
            this.present = false;

        }

        get_studnum(): i32 {
            return this.studnum;
        }

        get_sname(): string {
            return  this.sname;
        }

        get_present(): boolean {
            return this.present;
        }


}
4

2 回答 2

1

你的智能合约的逻辑有很多缺陷。

您声明 3 个对象，然后将这些对象保存在 PersistentVector 中。之后，您修改其中一个原始对象（不是保存在 PersistentVector 中的那个），然后打印这些对象。

在附近，您有 2 个“功能”来保存数据、存储或持久集合。如果你想保存一个类的状态，你必须使用其中一个函数（例如 PersistentVector）。

类不是持久对象，因此不会被保存。

于 2021-12-21T09:22:48.390 回答
1

我不是 100% 确定这是否有帮助，但在你的absent方法中，你可以尝试从你的PersistentVector, currstudents. 因为myStudent0是一个不同于存储在currstudents.

我发现我需要从列表中获取对象，进行更改，然后将其重新添加。

@mutateState()请注意：当使用单例模式时（与您使用的不同），如果我们更改类本身的状态，有时需要将装饰器添加到函数中。不过，我认为在您的情况下我们不需要它，因为学生们一PersistentVector开始就处于领先地位。

// @mutateState() decorator only needed if you change the state of the class
export function absent(): string{
    // mystudent0.set_absent();
    const student = currstudents[0];
    student.set_absent();
    currstudents[0] = student; // actually overwrites the student.
    return "absent";
}
于 2021-12-22T08:04:43.780 回答