c# - Using inheritance in constructor (publix X () : y) -

I have just seen the following code, but I did not understand the derivation of base class in the Constructor Manifesto. What is this and is it possible with gradual methods?

  Public SlashApp Synchtax (form main form, form splashform): base (splashform) {this.mainForm = mainForm; SplashTimer.Tick + = new event handler (splashtimeup); SplashTimer.Interval = 2000; SplashTimer.Enabled = true; } 
 
 This is calling a base class constructor, logic  splashForm < / Code> type  form  
 
 You can also call base class methods. If you have overridden a method for example, which you want to modify a bit, then you make your modifications and call the base code method at  base.Method () . This will look like this: 
 
  Public override zero firemissions () {primimissils (); Base.FireMissiles (); }  
 
 The syntax and the base class method for the base class constructor are different as you can see.