XpsDocument.GetFixedDocumentSequence throws XamlParseExcepti

我必须将.xlsx文件导入我的WPF应用程序并查看它。我将文档转换为。xps，然后加载。然后我调用GetFixedDocumentSequence()然后我得到这个Exception

XamlParseException:

{"UnicodeString属性没有包含足够的字符来{}.

下面是我的代码:

private void LoadData()
{
    string xpsPath = ViewDocumentViewer("D:''test.xlsx");
    DisplayXPSFile(xpsPath);
}
private string ViewDocumentViewer(string path)
{
    try
    {
        string xpsPath;
        var excelApp = new Microsoft.Office.Interop.Excel.Application();
        excelApp.DisplayAlerts = false;
        excelApp.Visible = false;
        Microsoft.Office.Interop.Excel.Workbook excelWorkbook = excelApp.Workbooks.Open(path);
        xpsPath = ExportXPS(excelWorkbook, path);
        excelWorkbook.Close(false, null, null);
        excelApp.Quit();
        Marshal.ReleaseComObject(excelApp);
        excelApp = null;
        return xpsPath;
    }
    catch
    { 
    }
    return string.Empty;
}
string ExportXPS(Microsoft.Office.Interop.Excel.Workbook excelWorkbook, string path)
{
    string xpsFileName;
    xpsFileName = (new DirectoryInfo(path)).FullName;
    xpsFileName = xpsFileName.Replace(new FileInfo(path).Extension, "") + ".xps";
    excelWorkbook.ExportAsFixedFormat(XlFixedFormatType.xlTypeXPS,
    Filename: xpsFileName,
    OpenAfterPublish: false);
    return xpsFileName;
}
void DisplayXPSFile(string xpsFileName)
{
    XpsDocument xpsPackage = new XpsDocument(xpsFileName, FileAccess.Read, CompressionOption.NotCompressed);
    FixedDocumentSequence fixedDocumentSequence = xpsPackage.GetFixedDocumentSequence();
    DocView.Document = fixedDocumentSequence;
}

<Canvas Clip="F 1 M137.710006714,208.58001709 L476.861022949,208.58001709 L476.861022949,208.58001709 L476.861022949,219.83001709 L476.861022949,219.83001709 L137.710006714,219.83001709 Z">
    <Glyphs OriginX="0" OriginY="0" UnicodeString="D" Indices=",55.6" Fill="#FF000000" FontRenderingEmSize="1" FontUri="/Resources/076a5115-0000-0000-0000-000000000000.odttf" RenderTransform="8.949999809,0,0,8.949999809,185.458496094,218.330078125" />
</Canvas>