Delegate Flashcards
What is a delegate in VB.NET?
A delegate is a type that represents references to methods with a specific parameter list and return type.
True or False: Delegates can only reference methods with the same signature.
True
Fill in the blank: A delegate can be declared using the keyword ____.
Delegate
What is the primary purpose of using delegates in VB.NET?
The primary purpose is to enable event handling and callback methods.
Which keyword is used to create an instance of a delegate?
New
True or False: A delegate can invoke multiple methods.
True
What is the syntax to declare a delegate that takes an integer and returns a string?
Public Delegate Function MyDelegate(ByVal number As Integer) As String
What method is used to combine two delegates?
Delegate.Combine
What is the return type of a delegate that does not return any value?
Void
What is the significance of the ‘AddHandler’ statement?
‘AddHandler’ associates an event with a delegate.
True or False: Delegates can be used as parameters for methods.
True
What is a multicast delegate?
A multicast delegate is a delegate that can call multiple methods in a single invocation.
How do you remove a method from a delegate?
Using the ‘RemoveHandler’ statement.
What is the keyword used to define an event in VB.NET?
Event
What is the purpose of the ‘Invoke’ method in the context of delegates?
The ‘Invoke’ method is used to call the method represented by the delegate.
Fill in the blank: A delegate can be assigned to a method that matches its ____.
Signature
What is the outcome of invoking a delegate that has no methods assigned?
It will not execute any code.
True or False: Delegates support asynchronous method calls.
True
What is the difference between a delegate and an event?
A delegate is a type that references methods, while an event is a notification mechanism that uses delegates.
What is the typical use case for delegates in GUI applications?
To handle user interface events like button clicks.
Fill in the blank: Delegates are similar to ____ in C#.
Function pointers
How do you define an event handler method for a delegate?
The method must match the delegate’s signature.
What is the purpose of the ‘BeginInvoke’ method?
To execute a delegate asynchronously.
What is the default access modifier for a delegate?
Public
True or False: Delegates can only be used with instance methods.
False
What happens if a delegate references a method that is no longer available?
An exception will be thrown when attempting to invoke the delegate.
What keyword is used to declare a delegate that can handle events?
EventHandler
