using System;
using System.IO;
using System.Drawing;
using System.Configuration;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using Microsoft.VisualBasic;
class PDFThumbnailCsharp
{
[STAThread]
static void Main(string[] args)
{
// Acrobat objects
Acrobat.CAcroPDDoc pdfDoc;
Acrobat.CAcroPDPage pdfPage;
Acrobat.CAcroRect pdfRect;
Acrobat.CAcroPoint pdfPoint;
AppSettingsReader appSettings = new AppSettingsReader();
string pdfInputPath = appSettings.GetValue("pdfInputPath", typeof(string)).ToString();
string pngOutputPath = appSettings.GetValue("pngOutputPath", typeof(string)).ToString();
string templatePortraitFile = Application.StartupPath + @"\pdftemplate_portrait.gif";
string templateLandscapeFile = Application.StartupPath + @"\pdftemplate_portrait.gif";;
try
{
// Get list of files to process from the input path
// Could change to read list from database instead
string[] files = Directory.GetFiles(pdfInputPath, "*.pdf");
for (int n=0; n < files.Length; n++)
{
string inputFile = files[n].ToString();
string outputFile = pngOutputPath + files[n].Substring(files[n].LastIndexOf(@"\")+1).Replace(".pdf", ".png");
/* Could skip if thumbnail already exists in output path
FileInfo fi = new FileInfo(inputFile);
if (!fi.Exists) {} */
// Create the document (Can only create the AcroExch.PDDoc object using late-binding)
// Note using VisualBasic helper functions, have to add reference to DLL in
// C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\Microsoft.VisualBasic.dll
// Will always be available as .NET framework ships with all
pdfDoc = (Acrobat.CAcroPDDoc) Microsoft.VisualBasic.Interaction.CreateObject("AcroExch.PDDoc", "");
bool boolret = pdfDoc.Open(inputFile);
int ret;
if (boolret == true)
{
ret = 1;
}
else
{
ret = 0;
}
if (ret == 0)
{
throw new FileNotFoundException();
}
// Get the number of pages (to be used later if you wanted to store that information)
int pageCount = pdfDoc.GetNumPages();
// Get the first page
pdfPage = (Acrobat.CAcroPDPage)pdfDoc.AcquirePage(0);
pdfPoint = (Acrobat.CAcroPoint)pdfPage.GetSize();
pdfRect = (Acrobat.CAcroRect) Microsoft.VisualBasic.Interaction.CreateObject("AcroExch.Rect", "");
pdfRect.Left = 0;
pdfRect.right = pdfPoint.x;
pdfRect.Top = 0;
pdfRect.bottom = pdfPoint.y;
// Render to clipboard, scaled by 100 percent (ie. original size)
// Even though we want a smaller image, better for us to scale in .NET
// than Acrobat as it would greek out small text
// see http://www.adobe.com/support/techdocs/1dd72.htm
pdfPage.CopyToClipboard(pdfRect, 0, 0, 100);
IDataObject clipboardData = Clipboard.GetDataObject();
if (clipboardData.GetDataPresent(DataFormats.Bitmap))
{
Bitmap pdfBitmap = (Bitmap)clipboardData.GetData(DataFormats.Bitmap);
// Size of generated thumbnail in pixels
int thumbnailWidth = 45;
int thumbnailHeight = 59;
string templateFile;
// Switch between portrait and landscape
if (pdfPoint.x < pdfPoint.y)
{
templateFile = templatePortraitFile;
}
else
{
templateFile = templateLandscapeFile;
// Swap width and height (little trick not using third temp variable)
thumbnailWidth = thumbnailWidth ^ thumbnailHeight;
thumbnailHeight = thumbnailWidth ^ thumbnailHeight;
thumbnailWidth = thumbnailWidth ^ thumbnailHeight;
}
// Load the template graphic
Bitmap templateBitmap = new Bitmap(templateFile);
// Render to small image using the bitmap class
Image pdfImage = pdfBitmap.GetThumbnailImage(thumbnailWidth, thumbnailHeight,
null, IntPtr.Zero);
// Create new blank bitmap (+ 7 for template border)
Bitmap thumbnailBitmap = new Bitmap(thumbnailWidth + 7, thumbnailHeight + 7,
System.Drawing.Imaging.PixelFormat.Format32bppArgb);
// To overlayout the template with the image, we need to set the transparency
// http://www.sellsbrothers.com/writing/default.aspx?content=dotnetimagerecoloring.htm
templateBitmap.MakeTransparent();
using (Graphics thumbnailGraphics = Graphics.FromImage(thumbnailBitmap))
{
// Draw rendered pdf image to new blank bitmap
thumbnailGraphics.DrawImage(pdfImage, 2, 2, thumbnailWidth, thumbnailHeight);
// Draw template outline over the bitmap (pdf with show through the transparent area)
thumbnailGraphics.DrawImage(templateBitmap, 0, 0);
// Save as .png file
thumbnailBitmap.Save(outputFile, System.Drawing.Imaging.ImageFormat.Png);
Console.WriteLine("Generated thumbnail... {0}", outputFile);
}
pdfDoc.Close();
// Not sure how why it is to do this, but Acrobat is not the best behaved COM object
// see http://blogs.msdn.com/yvesdolc/archive/2004/04/17/115379.aspx
Marshal.ReleaseComObject(pdfPage);
Marshal.ReleaseComObject(pdfRect);
Marshal.ReleaseComObject(pdfDoc);
}
}
}
catch (System.Exception ex)
{
Console.Write(ex.ToString());
}
}
}