Microsoft Surface: Where to define methods that have only be called during startup?

I have some methods, that should only be called during startup of the application. For now, I placed the methods in OnApplicationActivated:

private void OnApplicationActivate开发者_开发问答d(object sender, EventArgs e)
{
   Sound.loadSounds();             
   GetLocalProjects();
   GetProjects();            
}

But OnApplicationActivated isalso called, if the application was in the "pause" state (the shell is displayed) and is reactived. How can I avoid this? I want to call these methods only during startup.

I don't know anything about Microsoft Surface so I can't tell you if there are some other event that could be hooked up, but wouldn't an easy fix be to use a boolean instance variable to check whether initialization has been done or not?

bool _isInitialized = false;
private void OnApplicationActivated(object sender, EventArgs e) {    
  if( !_isInitialized ){
    Sound.loadSounds();
    GetLocalProjects();
    GetProjects();          
    _isInitialized = true;   
  }
}

boolean startup = true;
private void OnApplicationActivated(object sender, EventArgs e)
{
   If (startup)
   {
   Sound.loadSounds();             
   GetLocalProjects();
   GetProjects();
   startup = false; 
   }           
}

The Best fastest solution i could come up with

How would you do this for a non-Surface application? Override OnInitialized in your main window.