static void Main()
{
MyClass mc = new MyClass();
MyDel myDel = mc.Add2; // Create and initialize the delegate.
myDel += mc.Add3; // Add a method.
myDel += mc.Add2; // Add a method.
Console.WriteLine("Value: {0}", myDel()); // Invoke the delegate and use the return value.
}
static void Main()
{
MyClass instance = new MyClass();
MyDelegate myDelegate = new MyDelegate(instance.Method); // Создаем экземпляр делегата. (2)
myDelegate.Invoke(); // Вызываем метод сообщенный с делегатом. (3)
myDelegate(); // Другой способ вызова метода сообщенного с делегатом. (3')
// Delay.
Console.ReadKey();
}
static void Main()
{
MyClass mc = new MyClass();
MyDel myDel = mc.Add2;
myDel += mc.Add3;
myDel += mc.Add2;
int x = 5;
myDel(ref x);
Console.WriteLine("Value: {0}", x);
}
static void Main()
{
var instance = new MyClass();
// can refer an instance method
MyDelegate stringInspector = instance.CountCharacters;
// apelat ca o funcție; are un singură metodă
stringInspector("Vasile");
// can refer static methods
stringInspector += MyClass.PrintBeginning;
// apelat cu Invoke; are două funcții
stringInspector.Invoke("Cozonac");
stringInspector -= instance.CountCharacters;
// apelat asincron, just to mess with you
stringInspector.BeginInvoke(
"Paranoia",
ar =>
{
stringInspector.EndInvoke(ar);
Console.WriteLine("Am încheiat apelul asincron");
}, null);
Console.ReadKey(true);
// can create anonymous delegates
stringInspector += delegate (string s)
{
Console.WriteLine("„{0}” has {1} characters", s, s.Length);
};
stringInspector("masonerie");
// delegați pre-definiți
// are un parametru int
Action<int> action1;
// are un parametru int, unul string
Action<int, string> action2;
// returnează un întreg
Func<int> func1;
// are un parametru string, returnează un int
Func<string, int> func2;
// un fel de Func<T, bool>
Predicate<Uri> uriValidator;
}
static void Main()
{
MyClass instance = new MyClass();
MyDelegate myDelegate = new MyDelegate(instance.Method); // Создаем экземпляр делегата и сообщаем с ним метод. (2)
string greeting = myDelegate.Invoke("Jeffrey Richter"); // Вызываем метод сообщенный с делегатом. (3)
Console.WriteLine(greeting);
greeting = myDelegate("Grady Booch"); // Другой способ вызова метода сообщенного с делегатом. (3')
Console.WriteLine(greeting);
// Delay.
Console.ReadKey();
}
static void Main(string[] args)
{
// Class methods as delegates
Delegates.MyDelegate f;
f = Delegates.Func1;
Console.WriteLine("The number is: " + f(10, 20));
f = Delegates.Func2;
Console.WriteLine("The number is: " + f(10, 20));
// Object methods as delegates
MyClass mc = new MyClass();
f = mc.InstanceMethod1;
Console.WriteLine("The number is: " + f(10, 20));
// Anonymous delegates - e.g. delegate implementation is done inline.
f = delegate(int arg1, int arg2) { return (arg1/arg2).ToString(); };
Console.WriteLine("The number is: " + f(20, 20));
// Composable delegates - e.g. chaining delegate methods into one variable.
Delegates.MyDelegate f1 = Delegates.Func1;
Delegates.MyDelegate f2 = Delegates.Func2;
Delegates.MyDelegate composedDelegates = f1 + f2;
Console.WriteLine("The number of the delegate chain: " + composedDelegates(5, 5));
composedDelegates -= f2;
Console.WriteLine("The number of the delegate chain: " + composedDelegates(5, 5));
// Composable delegates w. references - e.g.
Delegates.MyRefDelegate ref1 = Delegates.RefFunc1;
Delegates.MyRefDelegate ref2 = Delegates.RefFunc2;
Delegates.MyRefDelegate combinedRefDels = ref1 + ref2;
int a = 10, b = 10;
combinedRefDels(a, ref b);
// End of theory
Console.WriteLine("==================END OF DELEGATE THEORY==================");
// Start of Exercise
Console.WriteLine("==================START OF DELEGATE EXERCISE==================");
// Variables
ShippingFeesDelegate theDel;
ShippingDestination theDest;
string theZone;
do
{
// Get the destination zone
Console.WriteLine("What is the destination zone?");
theZone = Console.ReadLine();
// Terminate the program if the user writes "exit"
if (!theZone.Equals("exit"))
{
// Given the zone, retrieve the associated shipping fee
theDest = ShippingDestination.GetShippingDestinationInfo(theZone);
// If there's no associated info, then the user entered an invalide zone, otherwise continue
if (theDest != null)
{
// Ask for price and convert the string to a decimal number
Console.WriteLine("What is the item price?");
string thePriceAsString = Console.ReadLine();
decimal itemPrice;
Decimal.TryParse(thePriceAsString, out itemPrice);
// Using calcFees delegate to calculate fee for item.
theDel = theDest.calcFees;
if (theDest._isHighRisk)
{
theDel += delegate(decimal thePrice, ref decimal itemFee) { itemFee += 25.0m; };
}
// Call delegate to calcualte shipping fee + write output
decimal theFee = 0.0m;
theDel(itemPrice, ref theFee);
Console.WriteLine($"The shipping fees are: {theFee}");
}
else
{
Console.WriteLine("Unknown destionation. Available zones are zone1 to zone4. Write exit to exit.");
}
}
} while (theZone != "exit");
// Start of Exercise
Console.WriteLine("==================END OF DELEGATE EXERCISE==================");
}
