static void Main(string[] args)
{
Del arithmeticMethod = Add;
var result = arithmeticMethod(10, 5);
Console.WriteLine($"Result is : {result}");//Prints 15
arithmeticMethod = Subtract;
result = arithmeticMethod(10, 5);
Console.WriteLine($"Result is : {result}");//Prints 5
Organization myOrg = new Organization();
LogExpense(myOrg.GetOfficeExpense, "OfficeExpense");
LogExpense(myOrg.GetAdministrationExpense, "Administration");
LogExpense(myOrg.GetSalary, "Salary");
LogExpense(() => { return((new Random()).Next(100, 200)); }, "Others");
}
static void Main(string[] args)
{
Program p = new Program();
//p.DivideTwoIntegers(5, 2, out int remainder);
//DivideTwoIntegers(1, 2, out int remainder2); Have to be static in order to use it without the p object
CalcInts mySum = p.Sum;
mySum(1, 2);
CalcInts myDiv = p.Div;
myDiv(1, 2);
CalcInts mySub = p.Sub;
mySub(1, 2);
CalcInts myCalcs = p.Sum;
myCalcs(1, 2);
myCalcs = p.Div;
myCalcs(1, 2);
myCalcs = p.Sub;
myCalcs(1, 2);
CalcInts myCalcAll = myDiv + mySub + mySum;//MULTICAST DELEGATE
//myCalcs(1, 2);
Console.WriteLine(myCalcAll(1, 2));
Del x = i => i * 10 + 1 - 2;
x(5);
//--------------------------
Home home = new Home();
home.Address = "Tritonos";
home.Name = "Michalopoulos";
PrintHome printDel;
printDel = give => Console.WriteLine($"{home.Address}, {home.Name}");
printDel(home);
//Console.WriteLine();
}
static void Main(string[] args)
{
Console.WriteLine("Let's talk about delegates. These may seem a little confusing at first," +
" but their main purpose is to pass methods as arguments to other methods.");
Console.WriteLine("Take event handlers for example. They are really just methods that are " +
"invoked using delegates.");
Console.WriteLine();
Console.WriteLine("So let's create a super simple delegate to see what it does.");
Console.WriteLine("We already created 'Del' which can handle any method that takes in a string.");
Console.WriteLine("We can now make a method into an object by calling:");
Console.WriteLine("Del handler = DelegateMethod");
Console.WriteLine("This is super useful because we can now put this in classes and structs.");
Console.WriteLine("Let's run this delegate and see what it does:");
Console.WriteLine();
// Instantiate the delegate.
Del handler = DelegateMethod;
// Call the delegate.
handler("Look I am a working delegate!");
Console.WriteLine();
Console.WriteLine("Delegates help us because we can then pass them into other methods.");
Console.WriteLine("Take the next example. We can pass in a string and the delegate, ");
Console.WriteLine("which we can then use to call the delegate method with the parameter");
Console.WriteLine("Take a look at what this method call does with Del as a param:");
Console.WriteLine();
MethodWithCallback("I'm called from a method, but use the delegate to write this message", handler);
Console.WriteLine();
Console.WriteLine("Let's look at a more practical example.");
}
private static void MethodWithCallback(string param, Del callback)
{
callback(param);
}
public static void MethodWithCallback(int param1, int param2, Del callback)
{
callback("The number is: " + (param1 + param2).ToString());
}
static void PerformArithmeticOps(Del method, int first, int second)
{
method(first, second);
}