EPPlus：尝试使用 SaveAs 方法时出现异常：无法加载类型 System.Security.Crytopgraphy.Pkcs.SignedCms

Question

我正在尝试将成功加载的 excel 文件保存为 .xlsm 文件，但出现以下错误：

{System.InvalidOperationException: Error saving file C:\VS\ExcelManager\ExcelManager\File.xlsm ---> System.TypeLoadException: Could not load type 'System.Security.Cryptography.Pkcs.SignedCms' from assembly 'System.Security, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
   at OfficeOpenXml.VBA.ExcelVbaSignature.GetSignature()
   at OfficeOpenXml.VBA.ExcelVbaSignature..ctor(ZipPackagePart vbaPart)
   at OfficeOpenXml.VBA.ExcelVbaProject.get_Signature()
   at OfficeOpenXml.VBA.ExcelVbaProject.Save()
   at OfficeOpenXml.ExcelWorkbook.Save()
   at OfficeOpenXml.ExcelPackage.Save()
   --- End of inner exception stack trace ---
   at OfficeOpenXml.ExcelPackage.Save()
   at OfficeOpenXml.ExcelPackage.SaveAs(FileInfo file)
   at ExcelManager.Controllers.ExcelController.PrepareExcelFile() in C:\VS\ExcelManager\ExcelManager\Controllers\ExcelController.cs:line 71
   at ExcelManager.Controllers.ExcelController.Get() in C:\VS\ExcelManager\ExcelManager\Controllers\ExcelController.cs:line 80
   at lambda_method(Closure , Object , Object[] )
   at Microsoft.Extensions.Internal.ObjectMethodExecutor.Execute(Object target, Object[] parameters)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionMethodAsync>d__12.MoveNext()}

}

这是在 .NET Core 2.0 中使用 EPPlus 的代码：

{namespace ExcelManager.Controllers
{
[Route("api/excel")]
public class ExcelController : Controller
{

    //private const string XlsxContentType = "application/vnd.ms-excel.sheet.macroEnabled.12";
    private const string XlsxContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";

    private void PrepareExcelFile()
    {
        //https://github.com/JanKallman/EPPlus/issues/31
        //Otherwise, I get an EPP error
        Encoding.RegisterProvider(CodePagesEncodingProvider.Instance); 

        ExcelPackage pck = new ExcelPackage(new System.IO.FileInfo("File.xlsx"));
        pck.Workbook.CreateVBAProject();
        var sb = new StringBuilder();
 //Add VBA Code here
        pck.Workbook.CodeModule.Code = sb.ToString();
        //Save as XLSM

        pck.SaveAs(new System.IO.FileInfo("File.xlsm"));}

我也尝试了 EPPlus.CORE nuget 包并收到了一个 "Not Supported Exception"。除了添加 VBA 代码外，我没有尝试对文件进行加密或做任何特殊的事情，而且我手动打开和保存文件没有问题。

如有任何想法，我们将不胜感激。

Answer 1

您的问题缺少一些信息，例如您使用的是什么版本的 EPPlus？

无论如何，我做了以下事情：

创建了一个 .Net Core 2.0 ASP.net 核心 MVC 项目。安装了 EPPLus prerelease v4.5.0.1-beta（支持.net core 2.0）并尝试了以下代码：

 ExcelPackage pck = new ExcelPackage(new System.IO.FileInfo("d:\a.xlsx"));
        var sb = new StringBuilder();
        //Add VBA Code here
        sb =new StringBuilder( "valid VB code");
        pck.Workbook.CreateVBAProject();
        pck.Workbook.CodeModule.Code = sb.ToString();
        //Save as XLSM

        pck.SaveAs(new System.IO.FileInfo("D:\a.xlsm"));

而且效果很好。

请确保您使用的是正确的 EPPlus 版本。

EPPlus：尝试使用 SaveAs 方法时出现异常：无法加载类型 System.Security.Crytopgraphy.Pkcs.SignedCms

EPPlus: Exception when attempting to use SaveAs method: Can't load type System.Security.Crytopgraphy.Pkcs.SignedCms

epplus

asp.net-core-mvc

.net-core