541 lines
15 KiB
Markdown
541 lines
15 KiB
Markdown
---
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title: Elsa Workflows 3
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date: 2026-06-17 13:21:19
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tags:
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---
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# Elsa Workflows 3 与 Activiti 5.14 对比指南
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## 核心架构差异
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| 概念 | Activiti 5.14 (Java) | Elsa Workflows 3 (.NET) |
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|------|---------------------|------------------------|
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| **流程定义** | BPMN 2.0 XML | C# 代码 / JSON / 可视化设计器 |
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| **任务模型** | 内置 UserTask 概念 | 阻塞活动 (Blocking Activity) + 书签 (Bookmark) |
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| **状态管理** | HistoryService 审计日志 | 自定义审计实现 |
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| **回滚支持** | 无原生支持，需自定义 | 有 Alterations API |
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| **API 风格** | Java 服务注入 | .NET 依赖注入 |
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---
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## 功能逐一对比
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### 1. 流程定义 (Process Definition)
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**Activiti 5.14:**
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```java
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// 使用 BPMN 2.0 XML 文件
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// process.bpmn20.xml
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<process id="approvalProcess" name="审批流程" isExecutable="true">
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<startEvent id="start"/>
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<userTask id="review" name="审核" activiti:assignee="${reviewer}"/>
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<endEvent id="end"/>
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<sequenceFlow sourceRef="start" targetRef="review"/>
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<sequenceFlow sourceRef="review" targetRef="end"/>
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</process>
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// 部署流程定义
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repositoryService.createDeployment()
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.addClasspathResource("process.bpmn20.xml")
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.deploy();
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```
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**Elsa Workflows 3:**
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```csharp
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// 方式1: C# 代码定义
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public class ApprovalWorkflow : Workflow
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{
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public override void Build(IWorkflowBuilder builder)
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{
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builder
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.HttpEndpoint("/start-approval", HttpMethod.Post)
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.Then<WaitForApprovalActivity>(activity =>
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{
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activity.ApprovalMessage = new("请审核此申请");
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})
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.WriteHttpResponse(HttpStatusCode.OK, "流程完成");
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}
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}
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// 方式2: JSON 定义
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{
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"definitionId": "approval-workflow",
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"name": "审批流程",
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"version": 1,
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"root": {
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"type": "Elsa.Flowchart",
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"activities": [
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{
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"id": "start",
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"type": "Elsa.HttpEndpoint",
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"path": "/start-approval"
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}
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]
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}
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}
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// 方式3: 使用 Elsa Studio 可视化设计器
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// 发布流程定义
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await workflowDefinitionsApi.SaveAsync(new SaveWorkflowDefinitionRequest
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{
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Model = new WorkflowDefinitionModel
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{
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DefinitionId = "approval-workflow",
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Name = "审批流程",
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IsPublished = true
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},
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Publish = true
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});
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```
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---
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### 2. 启动一个特定的流程 (Start a Specific Process)
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**Activiti 5.14:**
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```java
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Map<String, Object> variables = new HashMap<>();
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variables.put("applicant", "张三");
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variables.put("amount", 5000);
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ProcessInstance instance = runtimeService
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.startProcessInstanceByKey("approvalProcess", variables);
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String processInstanceId = instance.getId();
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```
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**Elsa Workflows 3:**
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```csharp
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// 方式1: 直接执行 (同步)
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var workflowRunner = serviceProvider.GetRequiredService<IWorkflowRunner>();
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var result = await workflowRunner.RunAsync<ApprovalWorkflow>(input: new Dictionary<string, object>
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{
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["Applicant"] = "张三",
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["Amount"] = 5000
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});
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// 方式2: 异步调度 (推荐用于生产环境)
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var dispatcher = serviceProvider.GetRequiredService<IWorkflowDispatcher>();
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await dispatcher.DispatchAsync(new DispatchWorkflowInstanceRequest
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{
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DefinitionId = "approval-workflow",
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Input = new Dictionary<string, object>
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{
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["Applicant"] = "张三",
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["Amount"] = 5000
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}
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});
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// 方式3: 通过 HTTP API
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// POST /api/workflow-definitions/approval-workflow/dispatch
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```
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---
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### 3. 获取下一流程的流程以及对应审核人列表 (Get Next Tasks and Approvers)
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**Activiti 5.14:**
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```java
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// 获取当前流程实例的任务
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List<Task> tasks = taskService.createTaskQuery()
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.processInstanceId(processInstanceId)
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.list();
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for (Task task : tasks) {
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System.out.println("任务名称: " + task.getName());
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System.out.println("处理人: " + task.getAssignee());
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System.out.println("创建时间: " + task.getCreateTime());
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}
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// 获取候选任务 (待认领)
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List<Task> candidateTasks = taskService.createTaskQuery()
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.taskCandidateUser("userId")
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.list();
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```
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**Elsa Workflows 3:**
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```csharp
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// Elsa 没有内置的"任务"概念，需要通过书签(Bookmarks)实现
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// 查询流程实例的书签 (类似当前待处理节点)
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var bookmarks = await bookmarkFinder
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.FindByWorkflowInstanceIdAsync(workflowInstanceId);
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foreach (var bookmark in bookmarks)
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{
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Console.WriteLine($"书签名称: {bookmark.Name}");
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Console.WriteLine($"活动类型: {bookmark.ActivityTypeName}");
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// 自定义: 需要从书签的 Payload 中提取审核人信息
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}
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// 推荐方案: 使用自定义状态管理
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public class ApprovalStateTracker
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{
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private readonly IWorkflowInstancesApi _workflowInstancesApi;
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public async Task<List<ApprovalStep>> GetNextApproversAsync(
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string workflowInstanceId)
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{
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// 从工作流变量中获取当前步骤和审核人
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var instance = await _workflowInstancesApi.GetAsync(workflowInstanceId);
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var currentStep = instance.Variables["CurrentStep"];
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var approvers = instance.Variables["NextApprovers"] as List<string>;
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return new List<ApprovalStep>
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{
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new ApprovalStep
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{
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StepName = currentStep.ToString(),
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Approvers = approvers
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}
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};
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}
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}
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```
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---
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### 4. 提交给下一流程至下一个审核人审核 (Submit to Next Approver)
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**Activiti 5.14:**
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```java
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// 认领任务
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taskService.claim(taskId, "userId");
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// 完成任务并传递变量
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Map<String, Object> variables = new HashMap<>();
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variables.put("approved", true);
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variables.put("comment", "同意申请");
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taskService.complete(taskId, variables);
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```
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**Elsa Workflows 3:**
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```csharp
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// 方式1: 通过书签ID恢复
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var input = new Dictionary<string, object>
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{
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["Decision"] = "Approved",
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["ApprovedBy"] = "manager@example.com",
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["Comment"] = "同意申请"
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};
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var result = await workflowResumer.ResumeAsync(bookmarkId, input);
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// 方式2: 通过 Stimulus (匹配书签)
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var stimulus = new
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{
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ApprovalId = approvalId,
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StepName = "ManagerReview"
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};
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await workflowResumer.ResumeAsync(stimulus, input);
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// 方式3: 通过 HTTP API (使用令牌URL)
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// POST /elsa/api/bookmarks/resume?t=ENCRYPTED_TOKEN
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// Body: { "input": { "Decision": "Approved", "ApprovedBy": "manager@example.com" } }
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// 自定义审核活动示例
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public class WaitForApprovalActivity : Activity
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{
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protected override async ValueTask ExecuteAsync(
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ActivityExecutionContext context)
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{
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var bookmarkArgs = new CreateBookmarkArgs
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{
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BookmarkName = "WaitForApproval",
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Payload = new Dictionary<string, object>
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{
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["ApprovalId"] = context.Get(ApprovalId),
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["CurrentStep"] = context.Get(CurrentStep)
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},
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Callback = OnApprovalReceivedAsync,
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AutoBurn = true // 使用一次后自动销毁
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};
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context.CreateBookmark(bookmarkArgs);
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}
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private async ValueTask OnApprovalReceivedAsync(
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ActivityExecutionContext context)
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{
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var decision = context.WorkflowInput["Decision"];
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var approvedBy = context.WorkflowInput["ApprovedBy"];
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// 记录审核历史
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await RecordApprovalHistoryAsync(decision, approvedBy);
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// 根据决策决定下一步
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if (decision.ToString() == "Approved")
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{
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await context.CompleteActivityWithOutcomesAsync("Approved");
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}
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else
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{
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await context.CompleteActivityWithOutcomesAsync("Rejected");
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}
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}
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}
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```
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---
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### 5. 获取退回到之前流程以及对应审核人列表 (Get Previous Tasks for Rollback)
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**Activiti 5.14:**
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```java
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// 获取历史任务
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List<HistoricTaskInstance> historicTasks = historyService
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.createHistoricTaskInstanceQuery()
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.processInstanceId(processInstanceId)
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.orderByHistoricTaskInstanceEndTime().desc()
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.list();
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for (HistoricTaskInstance task : historicTasks) {
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System.out.println("任务名称: " + task.getName());
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System.out.println("处理人: " + task.getAssignee());
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System.out.println("开始时间: " + task.getStartTime());
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System.out.println("结束时间: " + task.getEndTime());
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}
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```
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**Elsa Workflows 3:**
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```csharp
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// 需要自定义审计日志实现
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public class WorkflowAuditService
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{
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private readonly IAuditLogRepository _auditLogRepo;
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public async Task<List<AuditEntry>> GetApprovalHistoryAsync(
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string workflowInstanceId)
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{
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return await _auditLogRepo
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.GetByWorkflowInstanceIdAsync(workflowInstanceId);
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}
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public async Task RecordApprovalAsync(
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string workflowInstanceId,
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string stepName,
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string approver,
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string decision,
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string comment)
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{
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await _auditLogRepo.AddAsync(new AuditEntry
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{
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WorkflowInstanceId = workflowInstanceId,
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StepName = stepName,
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Approver = approver,
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Decision = decision,
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Comment = comment,
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Timestamp = DateTime.UtcNow
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});
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}
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}
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// 在审核活动的回调中记录历史
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private async ValueTask OnApprovalReceivedAsync(
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ActivityExecutionContext context)
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{
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var decision = context.WorkflowInput["Decision"];
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var approvedBy = context.WorkflowInput["ApprovedBy"];
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// 记录审核历史
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await _auditService.RecordApprovalAsync(
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context.WorkflowExecutionContext.Id,
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context.Get(CurrentStep),
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approvedBy.ToString(),
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decision.ToString(),
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context.WorkflowInput["Comment"]?.ToString());
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// 继续流程...
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}
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```
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---
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### 6. 退回到之前流程及其对应的审核人 (Rollback to Previous Task)
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**Activiti 5.14:**
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```java
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// 方案1: 使用流程变量 + 网关循环
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// 在 BPMN 中设计回退路径
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// 需要在 BPMN XML 中定义循环逻辑
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// 方案2: 使用信号事件
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runtimeService.signalEventReceived("rollbackSignal", variables);
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// 方案3: 自定义命令 (不推荐，侵入性强)
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```
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**Elsa Workflows 3:**
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```csharp
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// 方案1: 使用 Alterations API (推荐)
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await workflowAlterationService.AlterAsync(workflowInstanceId, alteration =>
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{
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// 修改工作流变量
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alteration.SetVariable("CurrentStep", "ManagerReview");
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alteration.SetVariable("NeedsRollback", true);
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});
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// 方案2: 取消当前书签，创建新书签
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public async Task RollbackToStepAsync(
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string workflowInstanceId,
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string targetStep,
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string targetApprover)
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{
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// 1. 获取当前书签
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var bookmarks = await bookmarkFinder
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.FindByWorkflowInstanceIdAsync(workflowInstanceId);
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// 2. 取消当前书签 (通过恢复并传递回退指令)
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var input = new Dictionary<string, object>
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{
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["Decision"] = "Rollback",
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["TargetStep"] = targetStep,
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["TargetApprover"] = targetApprover
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};
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// 3. 恢复工作流，触发回退逻辑
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await workflowResumer.ResumeAsync(bookmarks.First().Id, input);
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}
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// 方案3: 使用自定义回退活动
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public class RollbackActivity : Activity
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{
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protected override async ValueTask ExecuteAsync(
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ActivityExecutionContext context)
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{
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var targetStep = context.Get(TargetStep);
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var targetApprover = context.Get(TargetApprover);
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// 更新流程状态
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context.SetVariable("CurrentStep", targetStep);
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context.SetVariable("CurrentApprover", targetApprover);
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// 记录回退历史
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await RecordRollbackAsync(targetStep, targetApprover);
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// 完成活动，流程将根据条件网关回到目标步骤
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await context.CompleteActivityAsync();
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}
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}
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```
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---
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### 7. 流程的完结 (Process Completion)
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**Activiti 5.14:**
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```java
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// 方式1: 自然结束 (所有任务完成)
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taskService.complete(lastTaskId);
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// 方式2: 手动终止
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runtimeService.deleteProcessInstance(processInstanceId, "用户取消");
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// 方式3: 结束事件触发
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// 在 BPMN 中定义 endEvent
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```
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**Elsa Workflows 3:**
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```csharp
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// 方式1: 自然结束 (所有活动完成)
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// 当工作流执行到 End 活动时自动结束
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// 方式2: 手动取消
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var workflowCanceller = serviceProvider.GetRequiredService<IWorkflowCanceller>();
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await workflowCanceller.CancelAsync(workflowInstanceId);
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// 方式3: 通过 API
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// DELETE /api/workflow-instances/{instanceId}
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// 方式4: 使用 End 活动
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builder
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.Then<SomeActivity>()
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.Then<End>() // 工作流在此结束
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.WriteHttpResponse(HttpStatusCode.OK, "流程已完成");
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```
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---
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## 迁移建议
|
||
|
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### 设计模式推荐
|
||
|
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对于审批流程场景，建议在 Elsa 中采用以下设计：
|
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|
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```csharp
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public class ApprovalWorkflow : Workflow
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{
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public override void Build(IWorkflowBuilder builder)
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{
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builder
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// 开始
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.HttpEndpoint("/start", HttpMethod.Post)
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.Then<InitializeApprovalActivity>()
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|
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// 审核循环
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.Then<WaitForApprovalActivity>(activity =>
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{
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activity.ApprovalMessage = new("请审核");
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})
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.If(context => context.GetInput<string>("Decision") == "Approved",
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then => then.Then<ProcessApprovedActivity>(),
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@else => @else.Then<ProcessRejectedActivity>())
|
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// 结束
|
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.WriteHttpResponse(HttpStatusCode.OK);
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}
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}
|
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|
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// 状态跟踪服务
|
||
public class ApprovalTrackingService
|
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{
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// 记录每个步骤的审核人
|
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public async Task RecordStepAsync(
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string workflowId,
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ApprovalStep step)
|
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{
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// 存储到数据库
|
||
}
|
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|
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// 获取历史步骤 (用于回退)
|
||
public async Task<List<ApprovalStep>> GetHistoryAsync(
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string workflowId)
|
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{
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// 从数据库查询
|
||
}
|
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|
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// 获取下一个审核人
|
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public async Task<List<string>> GetNextApproversAsync(
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string workflowId)
|
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{
|
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// 根据业务规则计算
|
||
}
|
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}
|
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```
|
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|
||
---
|
||
|
||
## 关键差异总结
|
||
|
||
| 功能 | Activiti | Elsa | 迁移注意事项 |
|
||
|------|----------|------|-------------|
|
||
| 任务查询 | 原生支持 | 需自定义 | 需要实现状态跟踪服务 |
|
||
| 审计日志 | HistoryService | 需自定义 | 需要实现审计日志模块 |
|
||
| 回滚 | 无原生支持 | Alterations API | Elsa 有更好的扩展性 |
|
||
| 任务分配 | candidateUser/Group | 需自定义 | 需要在书签中存储分配信息 |
|
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|
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---
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## 总结
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Elsa Workflows 3 作为 .NET 工作流引擎，虽然在任务管理方面不如 Activiti 成熟，但提供了更灵活的扩展机制。迁移过程中需要：
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1. **重新设计任务模型**: 使用阻塞活动 + 书签替代内置 UserTask
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2. **实现审计服务**: 自定义审核历史记录
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3. **利用 Alterations API**: 实现流程回退功能
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4. **设计状态管理**: 通过工作流变量跟踪审批状态
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整体而言，Elsa 的架构更适合现代 .NET 应用，但需要更多的自定义实现来满足审批流程的完整需求。
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