When you need to pass sender and e to the method (e.g. a page control event) You can use null
Category: Objects
Determing an objects Type
Determining which object called method
E.g. you have a method like this: You can detect which object (ComboBox in this example) triggered it with this: If you use names that include an ID value, say:
Reference xaml object by name
Your xaml Your code that wants to alter it