private List <string> ConvertToImages(FileStream fs, List <string> returnStrings, Syncfusion.DocIO.FormatType type)
{
DocIO.WordDocument wd = new DocIO.WordDocument(fs, type);
//Instantiation of DocIORenderer for Word to PDF conversion
DocIORenderer render = new DocIORenderer();
//Converts Word document into PDF document
PdfDocument pdfDocument = render.ConvertToPDF(wd);
//Releases all resources used by the Word document and DocIO Renderer objects
render.Dispose();
wd.Dispose();
//Saves the PDF file
MemoryStream outputStream = new MemoryStream();
pdfDocument.Save(outputStream);
outputStream.Position = 0;
//Closes the instance of PDF document object
pdfDocument.Close();
PdfRenderer pdfExportImage = new PdfRenderer();
//Loads the PDF document
pdfExportImage.Load(outputStream);
//Exports the PDF document pages into images
Bitmap[] bitmapimage = pdfExportImage.ExportAsImage(0, pdfExportImage.PageCount - 1);
foreach (Bitmap bitmap in bitmapimage)
{
using (MemoryStream ms = new MemoryStream())
{
bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
returnStrings.Add("data:image/png;base64," + Convert.ToBase64String(ms.ToArray()));
}
}
return(returnStrings);
}
public string GetPreview([FromBody] FileManagerDirectoryContent args)
{
string baseFolder = this.basePath + "\\wwwroot\\Files";
try
{
String fullPath = baseFolder + args.Path;
string extension = Path.GetExtension(fullPath);
Stream imageStream = null;
if (extension == Constants.Pdf)
{
try
{
FileStream fileStream = new FileStream(fullPath, FileMode.Open, FileAccess.Read);
PdfRenderer pdfExportImage = new PdfRenderer();
//Loads the PDF document
pdfExportImage.Load(fileStream);
//Exports the PDF document pages into images
Bitmap[] bitmapimage = pdfExportImage.ExportAsImage(0, 0);
imageStream = new MemoryStream();
bitmapimage[0].Save(imageStream, System.Drawing.Imaging.ImageFormat.Png);
imageStream.Position = 0;
pdfExportImage.Dispose();
fileStream.Close();
}
catch
{
imageStream = null;
}
}
else if (extension == Constants.Docx || extension == Constants.Rtf || extension == Constants.Doc || extension == Constants.Txt)
{
try
{
FileStream fileStream = new FileStream(fullPath, FileMode.Open, FileAccess.Read);
//Loads file stream into Word document
DocIO.WordDocument document = new DocIO.WordDocument(fileStream, GetDocIOFormatType(extension));
fileStream.Dispose();
//Instantiation of DocIORenderer for Word to PDF conversion
DocIORenderer render = new DocIORenderer();
//Converts Word document into PDF document
PdfDocument pdfDocument = render.ConvertToPDF(document);
//Releases all resources used by the Word document and DocIO Renderer objects
render.Dispose();
document.Dispose();
//Saves the PDF file
MemoryStream outputStream = new MemoryStream();
pdfDocument.Save(outputStream);
outputStream.Position = 0;
//Closes the instance of PDF document object
pdfDocument.Close();
PdfRenderer pdfExportImage = new PdfRenderer();
//Loads the PDF document
pdfExportImage.Load(outputStream);
//Exports the PDF document pages into images
Bitmap[] bitmapimage = pdfExportImage.ExportAsImage(0, 0);
imageStream = new MemoryStream();
bitmapimage[0].Save(imageStream, System.Drawing.Imaging.ImageFormat.Png);
imageStream.Position = 0;
fileStream.Close();
}
catch
{
imageStream = null;
}
}
else if (extension == Constants.Pptx)
{
try
{
IPresentation presentation = Presentation.Open(fullPath);
//Initialize PresentationRenderer for image conversion
presentation.PresentationRenderer = new PresentationRenderer();
//Convert the first slide to image
imageStream = presentation.Slides[0].ConvertToImage(ExportImageFormat.Png);
presentation.Dispose();
}
catch
{
imageStream = null;
}
}
if (imageStream != null)
{
byte[] bytes = new byte[imageStream.Length];
imageStream.Read(bytes);
string base64 = Convert.ToBase64String(bytes);
return("data:image/png;base64, " + base64);
}
else
{
return("Error");
}
}
catch
{
return("Error");
}
}
