Question

我有一个我已启用Cors的WebAPI。

我的webAPI引用了一个类库，我在其中进行了大量的处理。

WebAPI和类库之间的调用以及类库中的一些调用是

抛出此错误......

{"Message":"An error has occurred.","ExceptionMessage":"Object reference not set to an instance of an object.",
"ExceptionType":"System.NullReferenceException","StackTrace":"   
at RCIS.MappingServices.WebAPI.Utilities.SQL.SQLInsertObjects(Int32 TypeMapId, Int32 GrowerId, Int32 CropYear, String NAME, String SHAPE, String CREATED_BY, String CREATED_DATETIME, String MODIFIED_BY, String MODIFIED_DATETIME, String IsDELETED)\r\n   
at RCIS.MappingServices.WebAPI.Controllers.PostObjectsController.GET(String TypeMapId, String GrowerId, String CropYear, String NAME, String SHAPE)\r\n   
at lambda_method(Closure , Object , Object[] )\r\n   
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)\r\n   
at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, 
IDictionary`2 arguments, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   
at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   
at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   
at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"}

这只是从服务器调用类库时发生的事情（即）我在Chrome中输入一个调用WebAPI方法的URL并返回此错误。

如果我在WebAPI中使用所有原始类型，那么在类库中我会收到成功的消息。

如果您有任何疑问，请告诉我。非常感谢任何帮助我一直试图解决这个问题2天！

Answer 1

确保您传递的唯一内容是字符串值。

Answer 2

制作一个ErrorHelper：

SELECT 
FLOOR(( DATE_FORMAT(NOW(),'%Y%m%d') - DATE_FORMAT(dob,'%Y%m%d'))/10000) as year,
FLOOR((1200 + DATE_FORMAT(NOW(),'%m%d')-DATE_FORMAT(dob,'%m%d'))/100) %12 as month,
CASE sign(day(NOW())-day(dob))
  WHEN 0 THEN 0
  WHEN 1 THEN day(NOW())-day(dob)
  ELSE (DAY(STR_TO_DATE(DATE_FORMAT(dob + INTERVAL 1 MONTH,'%Y-%m-01'),'%Y-%m-%d')-INTERVAL 1 DAY)-day(dob)+day(NOW())) END as day
FROM sampelaja

然后这样称呼：

public class ErrorHelper : IHttpActionResult
{
    private HttpRequestMessage Request { get; }
    private HttpStatusCode statusCode;
    private string message;

    public ErrorHelper(HttpRequestMessage request, HttpStatusCode statusCode, string message)
    {
        this.Request = request;
        this.statusCode = statusCode;
        this.message = message;
    }

    public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
    {
        return Task.FromResult(Request.CreateErrorResponse(statusCode, message));
    }
}

这将为您提供异常详细信息。您可能没有在服务器上安装组件，例如数据库驱动程序或类似的东西。

从WebAPI调用引用的dll在本地工作，但不在服务器上工作

2 个答案: