企业官网建设流程全解析

​

第14篇：考试引擎设计——ExamManager 与 ExamService 架构

一、引言

考试引擎是整个驾考应用的核心，负责试题管理、答题记录、分数统计等核心功能。DriverLicenseExam 项目通过ExamManager和ExamService两个核心类实现了完整的考试引擎。本文将深入解析其架构设计。

二、ExamService 数据服务

2.1 单例模式

ExamService 采用单例模式，确保整个应用只有一个数据服务实例：

// commons/datasource/src/main/ets/ExamService.ets@ObservedV2exportclassExamService{privatestatic_instance:ExamService;privateexamDetails:ExamDetail[] = [];@TracemockExamCount:number=0;@TracemockExamScore:number[] = [];staticcontext:Context;constructor() {this.examDetails=this.generateExamDetail(); }publicstaticinstance(context: Context) {ExamService.context= context;if(!ExamService._instance) {ExamService._instance=newExamService(); }returnExamService._instance; } }

2.2 核心数据统计方法

// 获取总题数publicgetTotalCount(): number {returnthis.examDetails.length; }// 获取已做题数publicgetDidCount(): number {returnthis.examDetails.filter(item => item.isCorrect !== undefined).length; }// 获取正确题数publicgetCorrectCount(): number {returnthis.examDetails.filter(item => item.isCorrect ===true).length; }// 获取错题数publicgetErrorCount(): number {returnthis.examDetails.filter(item => item.isCorrect ===false).length; }// 计算正确率publiccalAccuracyRate(): number {constrightCount =this.getCorrectCount();consttotalCount =this.getTotalCount();if(rightCount ===0)return0;returnMath.ceil(rightCount / totalCount *100); }// 计算平均分publiccalculateAverageScore(): number {if(this.mockExamCount ===0)return0;returnMath.ceil(this.mockExamScore.reduce((pre, next) => pre + next) /this.mockExamCount); }

三、ExamManager 试卷管理器

3.1 试卷数据结构

//ExamManager 管理一份试卷 export class ExamManager { name: string | Resource;//试卷名称 examDetails: ExamDetail[];//试题列表 currentQuestionId: number;//当前题目索引 correctNumber: number;//正确数 errorNumber: number;//错误数 timeLimit: number;//限时（0表示不限时） }

3.2 试卷获取策略

// 根据名称和类型获取试卷getManagerByName(name:string|Resource,type:EXAM_MANAGER_TYPE,currentQuestionId:number=0,chapterName:string='', wrongOrCollect?:WRONG_COLLECT):ExamManager{letexamManager =this.examManagerList.find(item=>item.name=== name);if(examManager ===undefined|| wrongOrCollect !==undefined) {constexamList =this.getExamQuestionList(type, chapterName, nameasstring, wrongOrCollect);constcorrectCount =this.getCorrectCountByManger(examList);consterrorCount =this.getErrorCountByManger(examList); examManager =newExamManager(name, examList, currentQuestionId, correctCount, errorCount);// 需要缓存的场景才缓存NEED_NEW_LIST.indexOf(type) === -1&&this.examManagerList.push(examManager); }returnexamManager; }// 模拟考试每次获取新试卷getMockExamManager(name:string| Resource) {letexamManager =newExamManager(name,this.generateExamDetail()); examManager.timeLimit=1;// 限时1分钟returnexamManager; }

四、试题数据模型

4.1 ExamDetail 数据结构

exportclassExamDetail{ question:string;// 题目文本image?:string;// 题目图片options:string[];// 选项列表correctAnswer:string[];// 正确答案questionType: QuestionTypeEnum;// 题型classificationType: ClassificationTypeEnum;// 难度analysis:string;// 解析chapterName:string;// 章节名称videoUrl:string;// 相关视频isCorrect?:boolean;// 是否答对isCollect:boolean;// 是否收藏selected:string[];// 已选答案}

4.2 题型枚举

export enum QuestionTypeEnum { RADIO =1,//单选题 CHECK_BOX =2,//多选题 JUDGE =3,//判断题 } export enum ClassificationTypeEnum { EASY =1,//容易 SIMPLE =2,//简单 MIDDLE =3,//一般 EASY_MISTAKE =4,//易错 HARD =5,//困难 }

五、总结

ExamService + ExamManager 构成了完整的考试引擎，实现了：

1. 数据管理：试题的增删改查
2. 统计计算：正确率、平均分等统计指标
3. 试卷管理：多种试卷类型的获取和缓存
4. 数据持久化：答题记录和进度的持久化

关键源码文件：

• commons/datasource/src/main/ets/ExamService.ets— 考试服务
• commons/datasource/src/main/ets/Model.ets— 数据模型
• components/exam/src/main/ets/model/QuestionAnswerRecord.ets— 答题记录

​