What is delegate how it is declared?
Declaration of Delegates Delegate type can be declared using the delegate keyword. Once a delegate is declared, delegate instance will refer and call those methods whose return type and parameter-list matches with the delegate declaration.
What is a delegate C#?
A delegate is a type that represents references to methods with a particular parameter list and return type. When you instantiate a delegate, you can associate its instance with any method with a compatible signature and return type. You can invoke (or call) the method through the delegate instance.
What is action C#?
Action is a delegate type defined in the System namespace. An Action type delegate is the same as Func delegate except that the Action delegate doesn’t return a value. In other words, an Action delegate can be used with a method that has a void return type.
How do I invoke a delegate?
Create the delegate and matching procedures
- Create a delegate named MySubDelegate .
- Declare a class that contains a method with the same signature as the delegate.
- Define a method that creates an instance of the delegate and invokes the method associated with the delegate by calling the built-in Invoke method.
What are the types of Delegates in C#?
There are three types of delegates that can be used in C#.
- Single Delegate.
- Multicast Delegate.
- Generic Delegate.
What’s a multicast delegate?
What is Multicast Delegate in C#? A Multicast Delegate in C# is a delegate that holds the references of more than one function. When we invoke the multicast delegate, then all the functions which are referenced by the delegate are going to be invoked.
What is the difference between func string string and delegate?
The basic difference between Func and Action delegates is that while the former is used for delegates that return value, the latter can be used for those delegates in which you don’t have any return value.
What is public delegate void?
public delegate void Del(string message); A delegate object is normally constructed by providing the name of the method the delegate will wrap, or with a lambda expression. Once a delegate is instantiated, a method call made to the delegate will be passed by the delegate to that method.
When should I use delegates C#?
When to use delegates?
- These are used to represent or refer to one or more functions.
- These can only be used to define call-back methods.
- In order to consume a delegate, we need to create an object to delegate.
What are the advantages of using delegates in C#?
- Delegates allow methods to be passed as parameters.
- Delegates are type safe function pointer.
- Delegate instances attach or detach a method at run time making it more dynamic and flexible to use.
- Delegates can invoke more than one method using the Multicast feature.
- Delegates are of reference types.
What is difference between delegate and events in C#?
Delegate is a function pointer. An event is dependent on a delegate and cannot be created without delegates. Event is a wrapper around delegate instance to prevent users of the delegate from resetting the delegate and its invocation list and only allows adding or removing targets from the invocation list.
Can delegates be private C#?
Just like classes and interfaces, we can declare delegates outside of classes or nested within classes. We can mark them private , public , or internal .