public void StartProcess(string fileName, string userName, string password, string args)
{
 var pwd = new SecureString();
 if (!string.IsNullOrEmpty(password))
 {
  password.ToCharArray().ToList().ForEach(c => pwd.AppendChar(c));
 }

 try
 {
  var process = new Process
  {
   StartInfo =
   {
    UseShellExecute = false,
    LoadUserProfile = true,
    UserName = userName,
    Password = pwd,
    Domain = ".",
    FileName = $"\"{fileName}\"",
    Arguments = args
   }
  };
  process.Start();
 }
 finally
 {
  pwd.Dispose();
 }
}

private void OpenPpt()
{
 var app = new Microsoft.Office.Interop.PowerPoint.Application();
}

private void ClosePpt(ref Application app)
{
 try
 {
  app?.Quit();
 }
 catch (Exception e)
 {
  Console.WriteLine(e.Message);
 }

 app = null;
 GC.Collect();
}

public void Open(object app, string filePath)
{
 var ppt = app as Microsoft.Office.Interop.PowerPoint.Application;
 if (ppt == null)
 {
  return;
 }

 //正斜杠替換為反斜杠
 filePath = filePath.Replace('/', '\\');

 try
 {
  //以只讀方式打開,方便操作結束后保存
  //使用一個不可能為密碼的值(AssemblyGuid)作為密碼打開PPT，保證有密碼時打開失敗
  var presentation = ppt.Presentations.Open(
   $"{filePath}::{Password}",
   MsoTriState.msoTrue, //ReadOnly: true
   MsoTriState.msoTrue, //Untitled: true
   MsoTriState.msoFalse); //WithWindow: false

  //獲取真實寬高
  var officeWidth = presentation.PageSetup.SlideWidth;
  var officeHeight = presentation.PageSetup.SlideHeight;

  //獲取頁數(shù)
  var pageNumber = presentation.Slides.Count;

  var slideShowSettings = presentation?.SlideShowSettings;
  if (slideShowSettings == null)
  {
   return;
  }

  var window = slideShowSettings.Run();
 }
 catch (Exception e)
 {
  Console.WriteLine(e.Message);
 }
}

public void Close(SlideShowWindow window)
{
 try
 {
  window?.View.Exit();
 }
 catch (Exception e)
 {
  Console.WriteLine(e.Message);
 }
}

public void GotoSlide(SlideShowWindow window, int index)
{
 try
 {
  window?.View.GotoSlide(index);
 }
 catch (Exception e)
 {
  Console.WriteLine(e.Message);
 }
}

public void Next(SlideShowWindow window)
{
 try
 {
  window?.View.Next();
 }
 catch (Exception e)
 {
  Console.WriteLine(e.Message);
 }
}

public void Previous(SlideShowWindow window)
{
 try
 {
  window?.View.Previous();
 }
 catch (Exception e)
 {
  Console.WriteLine(e.Message);
 }
}