using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using Microsoft.Office.Interop.PowerPoint;
//Office 命名空間
namespace OfficeToPdf
{
  //excel 類
  class PowerPointConverter
  {
    //構造函數
    public PowerPointConverter()
    { }
    /// <summary>
    /// 轉換PowerPoint 成PDF文檔
    /// </summary>
    /// <param name="_lstrInputFile">原文件路徑</param>
    /// <param name="_lstrOutFile">pdf文件輸出路徑</param>
    /// <returns>true 成功</returns>
    public bool ConverterToPdf(string _lstrInputFile, string _lstrOutFile)
    {
      Microsoft.Office.Interop.PowerPoint.Application lobjPowerPointApp = null;
      Microsoft.Office.Interop.PowerPoint.Presentation lobjppt = null;
      object lobjMissing = System.Reflection.Missing.Value;
      object lobjSaveChanges = null;
      try
      {
        lobjPowerPointApp = new Microsoft.Office.Interop.PowerPoint.Application();
        lobjppt = lobjPowerPointApp.Presentations.Open(_lstrInputFile, MSCore.MsoTriState.msoTrue, MSCore.MsoTriState.msoFalse, MSCore.MsoTriState.msoFalse);
        lobjppt.SaveAs(_lstrOutFile, PpSaveAsFileType.ppSaveAsPDF, MSCore.MsoTriState.msoCTrue);       
      }
      catch (Exception ex)
      {
        //其他日志操作；
        return false;
      }
      finally
      {
        if (lobjppt != null)
        {
          lobjppt.Close();
          Marshal.ReleaseComObject(lobjppt);
          lobjppt = null;
        }
        if (lobjPowerPointApp != null)
        {
          lobjPowerPointApp.Quit();
          Marshal.ReleaseComObject(lobjPowerPointApp);
          lobjPowerPointApp = null;
        }
        //主動激活垃圾回收器，主要是避免超大批量轉文檔時，內存占用過多，而垃圾回收器并不是時刻都在運行！
        GC.Collect();
        GC.WaitForPendingFinalizers();
      }
      return true;
    }
  }
}