Software for fun and profit

Hi,

I’m loving the power of Silverlight 5 Out of Browser (OOB) applications, now with improved file access and pInvoke. Thinking about deploying an OOB app to my users, I was wondering if I could create an OOB app that would launch itself when the OS starts.

Looking at how a user invokes the “Install SL OOB” operation by using the built in Silverlight Right Click menu, or a UI that the developer can create which calls the Application.Install() method, they are given 2 options: Desktop and/or Programs. Both of these essentially create a shortcut that launches the Silverlight OOB application using something like this:

"C:\Program Files (x86)\Microsoft Silverlight\sllauncher.exe" 2237722325.localhost

So I assumed I should be able to call the System.IO.File.Copy operation in my elevated trust SL5 OOB application and copy the link from the desktop or programs to the startup folder, but I was wrong. The System.IO.File.Copy operation throws a security exception if I try to write to the Startup folder?! I thought it was suppose to be able to do anything, but apparently NOT!.

pInvoke to the rescue!

Remembering that I could use Win32 APIs with the new pInvoke capabilities in SL5 elevated trust, I quickly replace the File.Copy with CopyFile from kernel32.dll and got it to work.

Enjoy the code.

JW.

Add this declaration to your class:

 [DllImport("kernel32.dll", CharSet = CharSet.Unicode, CallingConvention = CallingConvention.StdCall, SetLastError = true)]
 [return: MarshalAs(UnmanagedType.Bool)]
static extern bool CopyFile(
  [MarshalAs(UnmanagedType.LPWStr)]string lpExistingFileName,
  [MarshalAs(UnmanagedType.LPWStr)]string lpNewFileName,
  [MarshalAs(UnmanagedType.Bool)]bool bFailIfExists);

Add this function:

private void CreateShortcutInStartUP()

{
  try
  {
    Assembly app = Assembly.GetExecutingAssembly();
    //string version = app.FullName.Split(',')[1];
    //string fullVersion = version.Split('=')[1];

    string ApplicationName = string.Format("{0} Application", app.FullName.Split(',')[0]);

    if (ApplicationName != "")
    {
      string linkName = string.Format("{0}.lnk", ApplicationName);

      string DesktopShortcutPath =             Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
      DesktopShortcutPath = Path.Combine(DesktopShortcutPath, linkName);

      string StartUpPath = Environment.GetFolderPath(Environment.SpecialFolder.Programs);
      StartUpPath = Path.Combine(StartUpPath, "Startup");

      //MessageBox.Show(string.Format("StartUpPath = {0}",StartUpPath));
      //MessageBox.Show(string.Format("DesktopShortcutPath = {0}", DesktopShortcutPath));

      if (!System.IO.Directory.Exists(StartUpPath))
      {
        MessageBox.Show(string.Format("Cannot find: {0}", StartUpPath));
        return;
      }

      if (!System.IO.File.Exists(DesktopShortcutPath))
      {
         MessageBox.Show(string.Format("Cannot find: {0}", DesktopShortcutPath));
         return;
      }

      StartUpPath = Path.Combine(StartUpPath, linkName);
      //System.IO.File.Copy(ShortcutPath, newShortcutPath, true);
      if (CopyFile(DesktopShortcutPath, StartUpPath, false))
      {
        MessageBox.Show(string.Format("Copied to: {0}", StartUpPath));
      }
      else
      {
        MessageBox.Show("Failed to create Startup Shortcut.");
      }

    }
  }
  catch (Exception ex)
  {
    MessageBox.Show(ex.Message);
  }
}

Add call it from your startup code.