Question

当我点击此API时，会抛出一个无用的堆栈跟踪的TaskCanceledException。我正在使用这个库：https://npoi.codeplex.com/

public class TestController : ApiController
    {
        [HttpGet]
        public HttpResponseMessage Test()
        {
            var templateWorkbook = new XSSFWorkbook();
            var sheet = templateWorkbook.CreateSheet("TestSheet");
            IRow dataRow = sheet.CreateRow(4);
            var cell = dataRow.CreateCell(0);
            cell.SetCellValue(77);

            Stream memoryStream = new MemoryStream();
            templateWorkbook.Write(memoryStream);

            var httpResponseMessage = new HttpResponseMessage(HttpStatusCode.OK)
            {
                Content = new StreamContent(memoryStream)
            };
            httpResponseMessage.Content.Headers.ContentType = new MediaTypeHeaderValue("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            httpResponseMessage.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") { FileName = "test.xlsx" };
            return httpResponseMessage;
        }
    }

我做错了什么？这是我的堆栈跟踪：

[TaskCanceledException：任务被取消。]
  System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）+165
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）+58
  System.Web.Http.Owin.d__20.MoveNext（）+ 666 6   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）+137
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）+58
  System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd（任务任务）+25   System.Web.Http.Owin.d__0.MoveNext（）+1814
  System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）+137
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）+58
  Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.d__5.MoveNext（）   +187 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）+99
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）+58
  Microsoft.Owin.Security.Infrastructure.d__0.MoveNext（）+561
  System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）+137
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）+58
  Microsoft.Owin.Security.Infrastructure.d__0.MoveNext（）+561
  System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）+137
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）+58 Microsoft.Owin.Cors.d__0.MoveNext（）+856
  System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）+137
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）+58
  Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.d__5.MoveNext（）   +187 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）+99
  System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）+58
  Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.d__2.MoveNext（）   +185 Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.StageAsyncResult.End（IAsyncResult）   ar）+69
  Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.EndFinalWork（IAsyncResult的   ar）+64
  System.Web.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute（）   +380 System.Web.HttpApplication.ExecuteStep（IExecutionStep step，Boolean＆amp; completedSynchronously）+155

Answer 1

我找到了解决方案。

将内存流复制到另一个并将搜索位置重置为0似乎解决了这个问题：

MemoryStream memoryStream = new MemoryStream();
templateWorkbook.Write(memoryStream);
MemoryStream copy = new MemoryStream(memoryStream.ToArray());
copy.Seek(0, SeekOrigin.Begin);

看起来像NPOI库中的一个错误...

使用NPOI工作簿检索MemoryStream时抛出TaskCanceledException

1 个答案: