Explicit interface implementation in C Sharp (C#) - Mini Project: Build & Apply

Explicit Interface Implementation in C#

📖 Scenario: Imagine you are building a simple system where a device can perform different actions depending on the interface it implements. Sometimes the device needs to show different behavior for the same method name depending on the interface used.

🎯 Goal: You will create two interfaces with the same method name, then implement them explicitly in a class. Finally, you will call these methods through interface references to see the different outputs.

📋 What You'll Learn

Create two interfaces named IPrinter and IScanner each with a method void Start().

Create a class named MultiFunctionDevice that implements both interfaces explicitly.

Implement Start() method for IPrinter to print "Printer starting...".

Implement Start() method for IScanner to print "Scanner starting...".

Create instances of MultiFunctionDevice and call Start() through IPrinter and IScanner references.

Print the outputs exactly as specified.

💡 Why This Matters

🌍 Real World

Explicit interface implementation is useful when a device or component supports multiple protocols or behaviors that share method names but need different implementations.

💼 Career

Understanding explicit interface implementation is important for designing clean, maintainable code in large C# projects, especially when working with APIs or frameworks that require multiple interface implementations.

1

Create interfaces IPrinter and IScanner

Create two interfaces named IPrinter and IScanner. Each interface should have a method declaration void Start().

C Sharp (C#)

// Define interface IPrinter with void Start() method
// Define interface IScanner with void Start() method

Need a hint?

Use the interface keyword to define interfaces. Each interface should declare a method void Start(); without a body.

2

Create class MultiFunctionDevice implementing both interfaces

Create a class named MultiFunctionDevice that implements both IPrinter and IScanner interfaces explicitly. Implement Start() for IPrinter to print "Printer starting..." and for IScanner to print "Scanner starting...".

C Sharp (C#)

class MultiFunctionDevice : IPrinter, IScanner
{
    // Implement IPrinter.Start() explicitly
    // Implement IScanner.Start() explicitly
}

Need a hint?

Use explicit interface implementation syntax: void IPrinter.Start() and void IScanner.Start() inside the class.

3

Create instances and call Start() via interface references

Create an instance of MultiFunctionDevice named device. Create two variables: printer of type IPrinter and scanner of type IScanner, both referencing device. Call Start() on printer and scanner.

C Sharp (C#)

MultiFunctionDevice device = new MultiFunctionDevice();
// Create IPrinter variable printer referencing device
// Create IScanner variable scanner referencing device
// Call Start() on printer
// Call Start() on scanner

Need a hint?

Assign the device instance to interface variables and call Start() on each to see different outputs.

4

Print the outputs from explicit interface calls

Run the program and print the outputs from calling Start() on printer and scanner. The output should be exactly:
Printer starting...
Scanner starting...

C Sharp (C#)

// The output will be printed automatically when running the code

Need a hint?

Run the program to see the two lines printed exactly as shown.