C#中List<Task> taskList = new List<Task>(); taskList.Add(Task.Run(async () => { try { _log.LogInformation($"Start to update Thumbnail data, ID: {activityModel.Id}"); await ProcessThumbnail(activityModel.Thumbnail, activity, user); //throw new Exception(); } catch (Exception ex) { _log.LogError("An error: Upload Thumbnail is Invalid."); throw new Exception(); } })); taskList.Add(Task.Run(async () => { try { _log.LogInformation($"Start to add Attachments data, ID: {activityModel.Id}"); await ProcessAttachments(activityModel, activity, user); } catch (Exception ex) { _log.LogError("An error: Upload Attachment is Invalid."); throw new Exception(); } })); Task.WaitAll(taskList.ToArray());里面的task只执行了一个是什么原因

在这段代码中，`Task.Run` 方法会创建一个新的线程，并在该线程中执行传入的异步函数。`List<Task>` 中包含两个 `Task`，分别对应两个异步函数，即 `ProcessThumbnail` 和 `ProcessAttachments`。

在调用 `Task.WaitAll(taskList.ToArray())` 方法时，程序会等待所有的 `Task` 执行完毕后再继续往下执行。如果其中任意一个 `Task` 抛出了异常，整个程序会崩溃。

如果只有一个 `Task` 执行了，有可能是因为其中一个 `Task` 出现了异常，导致该 `Task` 执行失败，程序终止了。你可以通过在 `catch` 块中记录异常信息或者使用调试工具来确认是否有异常抛出。另外，你还可以在调用 `Task.WaitAll(taskList.ToArray())` 方法前，输出一些日志信息来确认程序的执行情况。

相关问题

修改下面代码：@Override public List<ProjectCountVO> projectCount(String beginTime, String endTime, Integer forceType, String projectId) { List<TaskTask> taskTaskList = this.listStatisticsTask(beginTime, endTime, forceType, projectId); if(CollectionUtil.isEmpty(taskTaskList)){ return Collections.emptyList(); } List<ProjectCountVO> result = new ArrayList<>(); Map<String, List<TaskTask>> projectTaskMap = taskTaskList.stream().collect(Collectors.groupingBy(TaskTask::getProjectId)); for (Map.Entry<String, List<TaskTask>> projectTaskEntry : projectTaskMap.entrySet()) { projectId = projectTaskEntry.getKey(); ProjectCountVO projectCountVO = new ProjectCountVO(); projectCountVO.setId(projectId); //查询项目名称 projectName = applicationServicePlatformClientProxy.get String projectName = Optional.ofNullable(projectTaskMap.get(projectId)).map(taskList -> taskList.get(0).getName()).orElse(""); projectCountVO.setName(projectName); List<TaskTask> taskList = projectTaskEntry.getValue(); projectCountVO.setTaskCount(taskList.size()); Integer problemCount = CollectionUtil.isEmpty(taskList) ? 0 : taskList.stream().collect(Collectors.summingInt(task-> Optional.ofNullable(task.getProblemNum()).orElse(0))); projectCountVO.setProblemCount(problemCount); result.add(projectCountVO); } return result; }

@Override
public List<ProjectCountVO> projectCount(String beginTime, String endTime, Integer forceType, String projectId) {
List<TaskTask> taskTaskList = this.listStatisticsTask(beginTime, endTime, forceType, projectId);
if (CollectionUtil.isEmpty(taskTaskList)) {
return Collections.emptyList();
}

List<ProjectCountVO> result = new ArrayList<>();
Map<String, List<TaskTask>> projectTaskMap = taskTaskList.stream().collect(Collectors.groupingBy(TaskTask::getProjectId));
for (Map.Entry<String, List<TaskTask>> projectTaskEntry : projectTaskMap.entrySet()) {
projectId = projectTaskEntry.getKey();
ProjectCountVO projectCountVO = new ProjectCountVO();
projectCountVO.setId(projectId);
//查询项目名称
String projectName = Optional.ofNullable(projectTaskMap.get(projectId)).map(taskList -> taskList.get(0).getProjectName()).orElse("");
projectCountVO.setName(projectName);

List<TaskTask> taskList = projectTaskEntry.getValue();
projectCountVO.setTaskCount(taskList.size());
Integer problemCount = CollectionUtil.isEmpty(taskList) ? 0 : taskList.stream().collect(Collectors.summingInt(task -> Optional.ofNullable(task.getProblemNum()).orElse(0)));
projectCountVO.setProblemCount(problemCount);

result.add(projectCountVO);
}
return result;
}

通过接口“applicationServicePlatformClient”在下面代码中调用projectname并打印代码：public List<ProjectCountVO> projectCount(String beginTime, String endTime, Integer forceType, String projectId) { List<TaskTask> taskTaskList = this.listStatisticsTask(beginTime, endTime, forceType, projectId); if(CollectionUtil.isEmpty(taskTaskList)){ return Collections.emptyList(); } List<ProjectCountVO> result = new ArrayList<>(); Map<String, List<TaskTask>> projectTaskMap = taskTaskList.stream().collect(Collectors.groupingBy(TaskTask::getProjectId)); for (Map.Entry<String, List<TaskTask>> projectTaskEntry : projectTaskMap.entrySet()) { projectId = projectTaskEntry.getKey(); ProjectCountVO projectCountVO = new ProjectCountVO(); projectCountVO.setId(projectId); //查询项目名称List<TaskTask> taskList = projectTaskEntry.getValue(); projectCountVO.setTaskCount(taskList.size()); Integer problemCount = CollectionUtil.isEmpty(taskList) ? 0 : taskList.stream().collect(Collectors.summingInt(task-> Optional.ofNullable(task.getProblemNum()).orElse(0))); projectCountVO.setProblemCount(problemCount); result.add(projectCountVO); } return result; }

您可以这样调用projectname并打印代码：

public List<ProjectCountVO> projectCount(String beginTime, String endTime, Integer forceType, String projectId) {
    List<TaskTask> taskTaskList = this.listStatisticsTask(beginTime, endTime, forceType, projectId);
    if(CollectionUtil.isEmpty(taskTaskList)){
        return Collections.emptyList();
    }

    List<ProjectCountVO> result = new ArrayList<>();
    Map<String, List<TaskTask>> projectTaskMap = taskTaskList.stream().collect(Collectors.groupingBy(TaskTask::getProjectId));

    for (Map.Entry<String, List<TaskTask>> projectTaskEntry : projectTaskMap.entrySet()) {
        projectId = projectTaskEntry.getKey();
        ProjectCountVO projectCountVO = new ProjectCountVO();
        projectCountVO.setId(projectId);
        
        // 查询项目名称
        String projectName = applicationServicePlatformClient.getProjectName(projectId);
        projectCountVO.setName(projectName);

        List<TaskTask> taskList = projectTaskEntry.getValue();
        projectCountVO.setTaskCount(taskList.size());
        Integer problemCount = CollectionUtil.isEmpty(taskList) ? 0 : taskList.stream().collect(Collectors.summingInt(task-> Optional.ofNullable(task.getProblemNum()).orElse(0)));
        projectCountVO.setProblemCount(problemCount);
        result.add(projectCountVO);
    }
    System.out.println("projectname: " + projectId);
    return result;
}

在for循环中，我们使用项目ID调用`applicationServicePlatformClient`的`getProjectName`方法，获取项目名称并设置到`ProjectCountVO`对象中。最后，在方法结束前打印`projectId`的值。