Task.ContinueWith()间歇性抛出TaskCancelledException及替代方案咨询

直接用async/await替代ContinueWith是更简洁且安全的方案，既能完成需求，又能避免间歇性的TaskCancelledException问题。

替代代码 #

var orgTasks = _options.TierRoutes
    .Select(async route => 
    {
        // 等待异步方法完成
        var organizations = await _ascendClient.FindAllOrganizations(
            new OrganizationSearchRequestModel { BaseAddress = route.BaseAddress });
        
        Console.WriteLine($"Completed request for {route.BaseAddress}");
        
        // 更新每个组织的TierName属性
        foreach (var organizationDetail in organizations)
        {
            organizationDetail.TierName = route.Name;
        }
        
        return organizations;
    });

// 等待所有任务完成
var result = await Task.WhenAll(orgTasks);

方案优势 #

• async/await会自动处理任务的完成、取消与异常传播，无需手动操作Task对象，从根源避免了ContinueWith中可能出现的取消异常处理疏漏。
• 代码逻辑更直观易读，减少了嵌套层级。
• 自动适配上下文调度，避免ContinueWith中可能出现的调度器配置问题。

可选异常处理 #

如果需要显式处理取消或其他异常，可以添加try/catch块：

var orgTasks = _options.TierRoutes
    .Select(async route => 
    {
        try
        {
            var organizations = await _ascendClient.FindAllOrganizations(
                new OrganizationSearchRequestModel { BaseAddress = route.BaseAddress });
            
            Console.WriteLine($"Completed request for {route.BaseAddress}");
            
            foreach (var organizationDetail in organizations)
            {
                organizationDetail.TierName = route.Name;
            }
            
            return organizations;
        }
        catch (TaskCanceledException ex)
        {
            Console.WriteLine($"Request for {route.BaseAddress} was cancelled: {ex.Message}");
            return Enumerable.Empty<OrganizationDetail>(); // 返回空列表或按需处理
        }
    });

var result = await Task.WhenAll(orgTasks);

内容的提问来源于stack exchange，提问作者Vinit Divekar