Answer Posted / kiran
Delegate is a class that can hold a reference to a method
or a function.Delegate class has
a signature and it can only reference those methods whose
signature is compliant with the
class.Delegates are type-safe functions pointers or
callbacks.
Below is a sample code which shows a example of how to
implement delegates.
Public Class FrmDelegates
Inherits System.Windows.Forms.Form
Public Delegate Sub DelegateAddString()
Private Sub FrmDelegates_Load(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
Private Sub AddString()
lstDelegates.Items.Add(“Running AddString() method”)
End Sub
Private Sub cmdDelegates_Click(ByVal sender As
System.Object,
ByVal e As System.EventArgs) Handles cmdDelegates.Click
Dim objDelegateAddString As DelegateAddString
objDelegateAddString = AddressOf AddString
objDelegateAddString.Invoke()
End Sub
End Class
In the above there is a method called “AddString()” which
adds a string to a listbox.You
can also see a delegate declared as :-
Public Delegate Sub DelegateAddString()
This delegate signature is compatible with the “AddString”
method.When i mean
compatibility that means that there return types and
passing parameter types are same.Later in command click of
the button object of the Delegate is created and the method
pointer
is received from “AddressOf ” keyword.Then by using
the “Invoke” method the method
is invoked.
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
How to assign Null value to Var?
what is be the overhead, if i use binary transmission. and will it be sent using xml text or how ?
What does question mark mean in c#?
Is c# used for any core features of windows vista?
What is the difference between == and object.equals?
what is the meaning of Object lifetime in OOPS
How many types of serialization are there in c#?
What is razor view in c#?
What is expression tree with example?
What is the difference between null and string empty in c#?
What does console readline do?
What is serialization in c#?
Why do we need interface in c#?
When can a derived class override a base class member?
What are the uses of namespaces?