Podcast
Questions and Answers
What is a delegate in .NET?
What is a delegate in .NET?
A class that encapsulates a method and is a reference type data type that holds a reference to a method.
To declare a delegate, you use the ______ keyword, followed by the return type, name, and parameters.
To declare a delegate, you use the ______ keyword, followed by the return type, name, and parameters.
delegate
Generic delegates can only reference methods that return and take parameters of the same specific type.
Generic delegates can only reference methods that return and take parameters of the same specific type.
False
What keyword is used to instantiate a delegate?
What keyword is used to instantiate a delegate?
Signup and view all the answers
Which of the following is the correct syntax to declare a delegate?
Which of the following is the correct syntax to declare a delegate?
Signup and view all the answers
After initializing the delegate, you can call it using ______ and parentheses.
After initializing the delegate, you can call it using ______ and parentheses.
Signup and view all the answers
What is the primary difference between delegates and interfaces?
What is the primary difference between delegates and interfaces?
Signup and view all the answers
Study Notes
Delegates Overview
- A delegate is a class in .NET that encapsulates a method, serving as a reference type data type.
- Delegates can invoke any method that matches their signature.
Declaring and Instantiating a Delegate
- Use the
delegatekeyword in a class to declare a delegate. - Syntax:
accessModifier delegate returnType delegateName(parameters).- Example:
public delegate int mathOp(int x, int y);
- Example:
- Instantiate a delegate using the
newkeyword linked to the method reference, e.g.,GetAnswer mdAdd = new GetAnswer(Formula.getSum);.
Invoking Delegates
- Delegates can invoke referenced methods; they must match the method's parameters.
- A delegate referencing a method that returns a value must declare its parameters accordingly.
- Example for invoking a method:
MessageBox.Show(delegateAddition(10,20).ToString());.
Generic Delegate Types
- Generic delegates are not limited to specific data types and can reference methods that accept various types.
- Declare generic delegates as
public delegate X DisplayOutput(X arg);.- This allows the generic delegate to point to methods with a return type and parameter of type X (e.g.,
double,string,int).
- This allows the generic delegate to point to methods with a return type and parameter of type X (e.g.,
Differences Between Delegates and Interfaces
- Delegates do not have implementations; they act as safe callbacks.
- Interfaces declare methods without implementations and require classes to define these methods.
Summary of Differences
- Delegates: No implementation, safe conveying of method references.
- Interfaces: Declarations needing implementations, promoting multiple method definitions from various classes.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on delegates in .NET with this quiz based on Harwani's work from 2015. You'll explore how delegates encapsulate methods and the importance of method signatures in their declaration and use. Join us to enhance your understanding of this essential .NET feature!
