Workbook.ExportToHtmlAsync(Stream, HtmlDocumentExporterOptions, CancellationToken) Method

Asynchronously exports the document’s data to the specified stream in HTML format using the specified options.

You need a license for the DevExpress Office File API Subscription or DevExpress Universal Subscription to use this method in production code.

Namespace: DevExpress.Spreadsheet

Assembly: DevExpress.Docs.v24.1.dll

NuGet Package: DevExpress.Document.Processor

Declaration

C#

public Task ExportToHtmlAsync(
    Stream stream,
    HtmlDocumentExporterOptions options,
    CancellationToken cancellationToken
)

VB.NET

Public Function ExportToHtmlAsync(
    stream As Stream,
    options As HtmlDocumentExporterOptions,
    cancellationToken As CancellationToken
) As Task

Parameters

Name	Type	Description
stream	Stream	A Stream object to which the created HTML file should be sent.
options	HtmlDocumentExporterOptions	A HtmlDocumentExporterOptions instance containing required export options.
cancellationToken	CancellationToken	A CancellationToken object used to trace the requests to cancel an operation.

Returns

Type	Description
Task	An Task object representing an asynchronous export operation.

Remarks

Important

Take into account the following when you call this method:

• The events fired by this method call may occur in a different thread than the target operation.

• The operation is not thread safe (the document should not be accessed simultaneously by different threads). Wait until the operation is completed before you continue to work with the document (for example, use the await operator).

The code sample below asynchronously exports the first worksheet of the loaded XLSX document to HTML using the CancellationToken object:

C#

private async void ConvertXlsx2HtmlWithCancellation()
{
  using (CancellationTokenSource source = new CancellationTokenSource(10000))
  {
    using (Workbook workbook = new Workbook())
      {
          try
          {
              await workbook.LoadDocumentAsync("Document.xlsx", source.Token);
              await workbook.ExportToHtmlAsync("Result.html", 0, source.Token);
          }
          catch (OperationCanceledException)
          {
              // Your code to handle cancellation.
          }
      }
  }
}

VB.NET

Private Async Sub ConvertXlsx2HtmlWithCancellation()
    Using source As CancellationTokenSource = New CancellationTokenSource(10000)

        Using workbook As Workbook = New Workbook()

            Try
                Await workbook.LoadDocumentAsync("Document.xlsx", source.Token)
                Await workbook.ExportToHtmlAsync("Result.html", 0, source.Token)
            Catch __unusedOperationCanceledException1__ As OperationCanceledException
            ' Your code to handle cancellation.
            End Try
        End Using
    End Using
End Sub

Calculate Formulas Before Export

The default calculation mode for a Workbook is Manual. This mode implies that the Spreadsheet does not recalculate formulas before it generates an HTML file. Call the Workbook.Calculate or Workbook.CalculateFull method to calculate all formulas in the workbook before you export it to HTML.