c# - 如何使用 C#/FileHelpers ExcelNPOIStorage 从 Excel 文件中提取数据

Question

我正在尝试使用 Filehelpers ExcelNPOIStorage 从 Excel 工作表中提取数据。因此我创建了一个类:

public static class UalExcelReader
    {
        public static UalShipmentRecord[] ReadInput(String pathToFile)
        {
            var provider = new ExcelNPOIStorage(typeof (UalShipmentRecord))
            {
                StartRow = 2,
                StartColumn = 1,
                FileName = pathToFile
            };
            var res = (UalShipmentRecord[]) provider.ExtractRecords();
            return res;
        }
    }

当然还有模型类:

[DelimitedRecord("|")]
public class UalShipmentRecord
{
    public string contentofcol1;
    public string contentofcol2;
    ...

}

但我在调用 ExtractRecords() 时遇到 IndexOutOfRangeException:

System.IndexOutOfRangeException was unhandled
  HResult=-2146233080
  Message=Index was outside the bounds of the array.
  Source=FileHelpers
  StackTrace:
       at FileHelpers.RecordOperations.ValuesToRecord(Object[] values)
       at FileHelpers.DataLink.DataStorage.ValuesToRecord(Object[] values)
       at FileHelpers.ExcelNPOIStorage.ExcelNPOIStorage.ExtractRecords()
       at Test.Controller.UalExcelReader.ReadInput(String pathToFile) in c:\TEMP\test\Test\Test\Test\Controller\UalExcelReader.cs:line 17
       at Test.App.OnStartup(StartupEventArgs eventArgs) in c:\TEMP\test\Test\Test\Test\App.xaml.cs:line 23
       at System.Windows.Application.<.ctor>b__1(Object unused)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
       at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
       at System.Windows.Threading.DispatcherOperation.InvokeImpl()
       at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Windows.Threading.DispatcherOperation.Invoke()
       at System.Windows.Threading.Dispatcher.ProcessQueue()
       at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
       at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
       at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
       at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
       at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
       at System.Windows.Threading.Dispatcher.Run()
       at System.Windows.Application.RunDispatcher(Object ignore)
       at System.Windows.Application.RunInternal(Window window)
       at System.Windows.Application.Run(Window window)
       at System.Windows.Application.Run()
       at Test.App.Main() in c:\TEMP\test\Test\Test\Test\obj\Debug\App.g.cs:line 0
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:

我是否正确使用它？有没有我可以看的例子？

Answer 1

1) 当您的 Excel 工作表中有空白单元格时，可能会发生此错误。这似乎是 ExcelNPOIStorage 检索给定行的值的方式中的一个潜在问题。

NPOI 使用 NPOI.CellWalk 遍历每行中的单元格，这似乎会跳过空白单元格。结果，Values 数组比预期的空白单元格数短。

看起来需要一种不同的方法，如此处所述:http://poi.apache.org/spreadsheet/quick-guide.html#Iterator

2) StartRow 和 StartColumn 值不正确会导致空白单元格不存在。

与 StartRow 和 StartColumn 的智能注释相反，对于 ExcelNPOIStorage 它们是从 0 开始的(而在 ExcelStorage 它们是基于 1 的)

来源:https://github.com/MarcosMeli/FileHelpers/blob/master/FileHelpers.ExcelNPOIStorage/Test/Program.cs

考虑到我遇到的问题，我赞成上面的评论并使用更可靠的旧 ExcelStorage 类，缺点是它依赖于 Excel Interop。