c# - 轮询Microsoft.VisualStudio.Services.Client的版本时发生NullReferenceException

我正在尝试实现一个简单的轮询服务，该服务将查询我们的TFS实例以获取构建结果（最终这将显示在办公室的构建监视器中）。按照示例here，我尝试了以下方法：

var uri = new Uri("http://tfs:8080/tfs/defaultcollection");
var connection = new VssConnection(uri, new VssClientCredentials());
var client = connection.GetClient<BuildHttpClient>();

var builds = await client.GetBuildsAsync(
    project: "OurProject",
    maxBuildsPerDefinition: 1,
    type: DefinitionType.Build);

但是最后一条语句在客户端库的深处抛出NullReferenceException（底部是完整堆栈跟踪）。

我已经尝试了以下方法，并且可以使用，但是当然它并不能为我提供所需的信息：）

var client = connection.GetClient<WorkItemTrackingHttpClient>();
var workItems = await client.GetWorkItemsAsync(ids: new List<int> { 7000, 7005});

我是否从根本上误解了有关如何查询构建的信息？如何避免这种异常？



更新：不只是我！

我只是发现不是（仅）在客户端生成此错误；它在服务器端（太）了！对以下网址的GET请求：

http://tfs:8080/tfs/defaultCollection/OurProject/_apis/build/builds?api-version=2.0&maxBuildsPerDefinition=1&type=build

产生具有以下内容的500 Internal Server Error响应：

{
  "$id": "1",
  "innerException": null,
  "message": "Object reference not set to an instance of an object.",
  "typeName": "System.NullReferenceException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089",
  "typeKey": "NullReferenceException",
  "errorCode": 0,
  "eventId": 0
}

鉴于此，我应该如何解决？我应该问/告诉运行我们的TFS服务器的操作人员什么？我们在找什么？



（客户端）异常的堆栈跟踪：

Unhandled Exception: System.AggregateException: One or more errors occurred.
---> Microsoft.VisualStudio.Services.WebApi.VssServiceResponseException: Object reference not set to an instance of an object.
---> System.NullReferenceException: Object reference not set to an instance of an object.
   --- End of inner exception stack trace ---
   at Microsoft.VisualStudio.Services.WebApi.VssHttpClientBase.HandleResponse(HttpResponseMessage response)
   at Microsoft.VisualStudio.Services.WebApi.VssHttpClientBase.SendAsync>d__49.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Services.WebApi.VssHttpClientBase.<SendAsync>d__47`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Services.WebApi.VssHttpClientBase.SendAsync>d__53`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Services.WebApi.VssHttpClientBase.<SendAsync>d__52`1.MoveNext()
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at System.Threading.Tasks.Task`1.get_Result()
   at ConsoleApplication1.Program.Work() in c:\users\tly01\documents\visual studio 2015\Projects\ConsoleApplication1\ConsoleApplication1\Program.cs:line 32
   at ConsoleApplication1.Program.Main(String[] args) in c:\users\tly01\documents\visual studio 2015\Projects\ConsoleApplication1\ConsoleApplication1\Program.cs:line 20

最佳答案

我发现了错误。简短的回答，RTFM :)

事实证明，仅当还指定了maxBuildsPerDefinition时，definitions参数才有效。如果仅给出前者，则服务器返回500。

（您可能会说“ 401错误的请求”会是更好的响应，但至少现在我知道该怎么做了。）

我的解决方法是在客户端进行过滤；我得到所有项目的所有构建，然后按定义分组并选择最新的一个：

var builds = await client
    .GetBuildsAsync(
        project: "OurProject",
        type: DefinitionType.Build).Result
    .GroupBy(build => build.Definition.Id)
    .Select(g => g
        .OrderByDescending(build.FinishTime ?? build.StartTime ?? DateTime.MinValue)
        .First());

关于c# - 轮询Microsoft.VisualStudio.Services.Client的版本时发生NullReferenceException，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/34918426/