IDocumentFormatDetector.Detect(Stream) Method

Returns the format of a file contained in the stream.

Namespace: DevExpress.Blazor.RichEdit

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

Declaration

DocumentFormat Detect(
    Stream stream
)

Parameters

Name	Type	Description
stream	Stream	The stream that contains the document.

Returns

Type	Description
DocumentFormat	The format of the document.

Remarks

The Rich Text Editor automatically detects the document’s format when you call the LoadDocumentAsync(Stream, CancellationToken) method to load a document from a specified stream. Override the Detect method to implement your own file format detection logic.

The following code snippet implements the IDocumentFormatDetector interface and its Detect methods.

public class MyDocumentFormatDetector : IDocumentFormatDetector {
  public DocumentFormat Detect(string filePath) {
    if(!File.Exists(filePath)) {
      switch(Path.GetExtension(filePath)) {
        case ".rtf":
          return DocumentFormat.Rtf;
        case ".docx":
          return DocumentFormat.OpenXml;
        default:
          return DocumentFormat.PlainText;
      }
    } else {
      using(var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read)) {
        return Detect(stream);
      }
    }
  }
  public DocumentFormat Detect(Stream stream) {
    if(!stream.CanSeek)
      return DocumentFormat.PlainText;
    stream.Seek(0, SeekOrigin.Begin);
    var head = new byte[5];
    stream.Read(head, 0, head.Length);
    stream.Seek(0, SeekOrigin.Begin);
    if(Encoding.ASCII.GetString(head, 0, 2) == "PK")
      return DocumentFormat.OpenXml;
    else if(Encoding.ASCII.GetString(head) == "{\\rtf")
      return DocumentFormat.Rtf;
    return DocumentFormat.PlainText;
  }
}

// Registers the MyDocumentFormatDetector in the application's services
public void ConfigureServices(IServiceCollection services) {
  // ...
  services.AddSingleton<IDocumentFormatDetector>(new MyDocumentFormatDetector());
}