HtmlSaveOptions.CssStyleSheetFileName property

Specifies the path and the name of the Cascading Style Sheet (CSS) file written when a document is exported to HTML. Default is an empty string.

public string CssStyleSheetFileName { get; set; }


This property has effect only when saving a document to HTML format and external CSS style sheet is requested using CssStyleSheetType.

If this property is empty, the CSS file will be saved into the same folder and with the same name as the HTML document but with the “.css” extension.

If only path but no file name is specified in this property, the CSS file will be saved into the specified folder and will have the same name as the HTML document but with the “.css” extension.

If the folder specified by this property doesn’t exist, it will be created automatically before the CSS file is saved.

Another way to specify a folder where external CSS file is saved is to use ResourceFolder.


Shows how to work with CSS stylesheets that an HTML conversion creates.

public void ExternalCssFilenames()
    Document doc = new Document(MyDir + "Rendering.docx");

    // Create an "HtmlFixedSaveOptions" object, which we can pass to the document's "Save" method
    // to modify how we convert the document to HTML.
    HtmlSaveOptions options = new HtmlSaveOptions();

    // Set the "CssStylesheetType" property to "CssStyleSheetType.External" to
    // accompany a saved HTML document with an external CSS stylesheet file.
    options.CssStyleSheetType = CssStyleSheetType.External;

    // Below are two ways of specifying directories and filenames for output CSS stylesheets.
    // 1 -  Use the "CssStyleSheetFileName" property to assign a filename to our stylesheet:
    options.CssStyleSheetFileName = ArtifactsDir + "SavingCallback.ExternalCssFilenames.css";

    // 2 -  Use a custom callback to name our stylesheet:
    options.CssSavingCallback =
        new CustomCssSavingCallback(ArtifactsDir + "SavingCallback.ExternalCssFilenames.css", true, false);

    doc.Save(ArtifactsDir + "SavingCallback.ExternalCssFilenames.html", options);

/// <summary>
/// Sets a custom filename, along with other parameters for an external CSS stylesheet.
/// </summary>
private class CustomCssSavingCallback : ICssSavingCallback
    public CustomCssSavingCallback(string cssDocFilename, bool isExportNeeded, bool keepCssStreamOpen)
        mCssTextFileName = cssDocFilename;
        mIsExportNeeded = isExportNeeded;
        mKeepCssStreamOpen = keepCssStreamOpen;

    public void CssSaving(CssSavingArgs args)
        // We can access the entire source document via the "Document" property.

        args.CssStream = new FileStream(mCssTextFileName, FileMode.Create);
        args.IsExportNeeded = mIsExportNeeded;
        args.KeepCssStreamOpen = mKeepCssStreamOpen;


    private readonly string mCssTextFileName;
    private readonly bool mIsExportNeeded;
    private readonly bool mKeepCssStreamOpen;

See Also