How to convert a Docx file (held in a Stream) to a PDF file (as a Stream) using Spire.Doc

Question

I need a NuGet which is able to convert .docx files to .pdfs, for free. I stumbled accross FreeSpire.Doc but I am having trouble using it.

Here's my code:

using mediere_API.Processors.Interfaces;
using Spire.Doc;

namespace mediere_API.Processors.Implementations;

public class SpireProcessor : ISpireProcessor
{
  public Stream ConvertDocxToPdf(Stream document)
  {
    Document doc = new Document();
    document.Position = 0;
    doc.LoadFromStream(document, FileFormat.Auto);
    var finalFileStream = new MemoryStream();
    doc.SaveToStream(finalFileStream, FileFormat.PDF);
    return finalFileStream;
  }
}

On the line with doc.SaveToStream, I get this exception:

System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at spr↨.ᜀ(Byte[] A_0)
   at sprẃ..ctor(PointF A_0, SizeF A_1, Byte[] A_2, spr↌ A_3)
   at sprẃ..ctor(PointF A_0, SizeF A_1, Byte[] A_2)
   at spr㏃.ᜀ(PointF A_0, PointF A_1, Single A_2, Boolean A_3)
   at spr㏃.ᜀ(PointF A_0, PointF A_1, Single A_2)
   at spr㏃.ᜁ(spr㈻ A_0)
   at spr㏃.ᜀ(spr㏀ A_0, spr㏀ A_1, Boolean A_2, spr㈻ A_3)
   at spr㎿.ᜁ(spr㈻ A_0)
   at spr㎿.ᜃ(spr㈻ A_0)
   at spr⛃.ᜂ(spr⓬ A_0)
   at spr⓬.ᜀ(spr⓭ A_0)
   at sprⓘ.ᜀ(spr⓭ A_0, spr✕ A_1)
   at sprⓒ.ᜀ(spr⓭ A_0)
   at sprⓓ.ᜀ(spr⓭ A_0)
   at sprⓚ.ᜀ(spr⓭ A_0)
   at spr⛃.ᜀ(sprⓚ A_0)
   at spr⛃.ᜀ(sprⓚ A_0, spr⒵ A_1)
   at Spire.Doc.Document.ᜀ(Int32 A_0, spr⛃ A_1)
   at sprⷎ.ᜀ(spr⍿ A_0, spr⛃ A_1)
   at sprⷎ.ᜂ(spr⍿ A_0)
   at Spire.Doc.Document.ᜅ(Stream A_0, ToPdfParameterList A_1)
   at Spire.Doc.Document.ᜁ(Stream A_0)
   at Spire.Doc.Document.SaveToFile(Stream stream, FileFormat fileFormat)
   at Spire.Doc.Document.SaveToStream(Stream stream, FileFormat fileFormat)
   at mediere_API.Processors.Implementations.SpireProcessor.ConvertDocxToPdf(Stream document) in /home/octavian/Desktop/bestdavnic73/mediere-api/Processors/Implementations/SpireProcessor.cs:line 14
   at mediere_API.Processors.Implementations.PersoanaProcessor.CreateAnexaPlanMediereAsync(Int32 persoanaId, Nullable`1 startDate, Nullable`1 endDate) in /home/octavian/Desktop/bestdavnic73/mediere-api/Processors/Implementations/PersoanaProcessor.cs:line 339
   at mediere_API.Controllers.PersoaneController.CreateAnexaMediere(Int32 Id, String startDate, String endDate) in /home/octavian/Desktop/bestdavnic73/mediere-api/Controllers/PersoaneController.cs:line 138
   at lambda_method134(Closure, Object)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfActionResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at mediere_API.Middleware.SchemaHandlingMiddleware.InvokeAsync(HttpContext context, ITenantProcessor tenantProcessor) in /home/octavian/Desktop/bestdavnic73/mediere-api/Middleware/SchemaHandlingMiddleware.cs:line 32
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)

and I cannot understand why.

I tried to edit my code in multiple ways, but nothing seems to make it work. I always get this error.

Also, if I change FileFormat.PDF to FileFormat.docx, I get no error but the file is a word document, not a PDF, as I intend.

So, why am I getting this exception and how can I fix it?

Thanks.

Edit: I get the same error if I change doc.SaveToStream to

    doc.SaveToFile("/var/tmp/test.pdf", FileFormat.PDF);

Answer 1

For anybody that might have this problem, the document that was passed to this function was generated with OpenXML. For some reason, for those borders:

TableBorders tabelLMVBorders = new TableBorders(
                        new TopBorder() { Val = new EnumValue<BorderValues>(BorderValues.BasicThinLines), Size = 6 },
                        new BottomBorder() { Val = new EnumValue<BorderValues>(BorderValues.BasicThinLines), Size = 6 },
                        new LeftBorder() { Val = new EnumValue<BorderValues>(BorderValues.BasicThinLines), Size = 6 },
                        new RightBorder() { Val = new EnumValue<BorderValues>(BorderValues.BasicThinLines), Size = 6 },
                        new InsideHorizontalBorder() { Val = new EnumValue<BorderValues>(BorderValues.BasicThinLines), Size = 6 },
                        new InsideVerticalBorder() { Val = new EnumValue<BorderValues>(BorderValues.BasicThinLines), Size = 6 });

I get that error. To be more specific, for the InsideHorizontalBorder/InsideVerticalBorder ones, I don't know why. If I don't use those two, everything works fine.