Demonstrate using a static delegate without declaring an instance of the class : delegate « Language Basics « C# / C Sharp






Demonstrate using a static delegate without declaring an instance of the class

Demonstrate using a static delegate without declaring an instance of the class

/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa

Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
// StaticDl.cs -- Demonstrate using a static delegate without declaring
//                an instance of the class.
//
//                Compile this program with the following command line:
//                    C:>csc StaticDl.cs
using System;

namespace nsDelegates
{
    public class StaticDl
    {
        public delegate void StringHandler (string str);
        static public StringHandler DoString;

        static public void Main ()
        {
// Create a delegate in this class
            DoString = new StringHandler (ShowString);
            DoString ("Static delegate called");
//
// Show that the static constructor in another class is shared by instances
            clsDelegate.DoMath = new clsDelegate.MathHandler (SquareRoot);
            clsDelegate dlg1 = new clsDelegate (49);
            clsDelegate dlg2 = new clsDelegate (3.14159);
        }
// The method used with the string delegate
        static private void ShowString (string str)
        {
            Console.WriteLine (str);
        }
// The method used with the double delegate
        static private double SquareRoot (double val)
        {
            double result = Math.Sqrt (val);
            Console.WriteLine ("The square root of " + val + " is " + result);
            return (result);
        }
    }
    class clsDelegate
    {
        public delegate double MathHandler (double val);
        static public MathHandler DoMath;
// The constructor invokes the delegate if it is not null.
        public clsDelegate (double val)
        {
            value = val;
            if (DoMath != null)
                sqrt = DoMath (value);
        }
        double value;
        double sqrt = 0;
    }
} 



           
       








Related examples in the same category

1.Define your own delegateDefine your own delegate
2.Late Binding Delegates: A delegate is a repository of type-safe function pointers.
3.illustrates the use of a delegate 2illustrates the use of a delegate 2
4.illustrates the use of a multicast delegateillustrates the use of a multicast delegate
5.illustrates the use of a delegate that calls object methodsillustrates the use of a delegate that calls object methods
6.Demonstrates a simple form of a delegateDemonstrates a simple form of a delegate
7.Demonstrates combining and removing delegates to create new delegatesDemonstrates combining and removing delegates to create new delegates
8.Demonstrate getting and printing the invocation list for a delegateDemonstrate getting and printing the invocation list for a delegate
9.Demonstrates adding multiple methods to a delegateDemonstrates adding multiple methods to a delegate
10.Using a delegate with a container class to sort the collection and return a sorted array using different sort criteriaUsing a delegate with a container class 
       to sort the collection and return a sorted array using different 
       sort criteria
11.A simple delegate exampleA simple delegate example
12.Delegates can refer to instance methods, tooDelegates can refer to instance methods, too
13.Two delegates
14.The minimum implementation of a delegateThe minimum implementation of a delegate
15.Delegates:Using Delegates
16.Delegates to Instance MembersDelegates to Instance Members
17.Delegates:MulticastingDelegates:Multicasting
18.Arrays of Delegates
19.To remove delegates from a multicast delegate, use the Remove method, the minus operator (-), or the -= assignment operator.
20.the syntax of the GetInvocationList method: delegate [] GetInvocationList()
21.The publisher/subscriber relationship is a one-to-many relationship.
22.Lifetime of outer variables is aligned with the delegate
23.Combining delegates Multiple delegates are combined using the Combine method, the plus operator (+), or the += assignment operator.
24.CreateDelegate and DynamicInvoke