static void Main1(string[] args)
{
Mydele obj = new Mydele(Display);
obj(5);
Mydele1 obj1 = new Mydele1(add);
int i = obj1(5);
Console.WriteLine("add method called with delegate and addition is: " + i);
Mydel2 obj2 = new Mydel2(multiply);
int c = obj2(5, 6);
Console.WriteLine("Multiply method called " + c);
//Method in another class
Class1 o = new Class1();
Mydel3 obj3 = Class1.divide;
int d = obj3(25, 25);
Console.WriteLine("Divide method called " + d);
dele ob = o.dis;
ob();
Console.ReadLine();
}
static void Main(string[] args)
{
string s = "kk";
Mydel obj = delegate(int a, int b)
{
return(a + b);
};
Console.WriteLine(obj(10, 20));
Mydel2 obj1 = delegate()
{
Console.WriteLine("Print the display function " + s);
};
obj1();
Console.ReadLine();
}
static void Main(string[] args)
{
Console.WriteLine("***Quiz on Delegate***");
int a = 25, b = 37, c = 100;
A obA1 = new A();
A obA2 = new A();
Mydel1 del1 = obA1.Sum;//Pointing Sum(int a, int b)
Console.WriteLine("del1 is pointing Sum(int a,int b):");
Console.WriteLine("Sum of a and b is: {0}", del1(a, b));
Mydel2 del2 = obA1.Sum;//pointing Sum(int a, int b, int c)
Console.WriteLine("del2 is pointing Sum(int a,int b,int c):");
Console.WriteLine("Sum of a, b and c is: {0}", del2(a, b, c));
//same as
//Console.WriteLine("Sum of a, b and c is: {0}", del2.Invoke(a, b, c));
Console.ReadKey();
}
static void Main(string[] args)
{
Vehicle vehicle1 = new Vehicle(); //ok
Bus bus1 = new Bus(); //ok
Console.WriteLine("***Exploring Contravariance with C# delegates * **");
//General case
TakingDerivedTypeParameterDelegate del1 = bus1.ShowBus;
del1(bus1);
//Special case:
//Contravariance:
/*Note that the delegate expected a method that accepts a
* bus(derived) object parameter but still it can point to the
* method that accepts vehicle(base) object parameter*/
TakingDerivedTypeParameterDelegate del2 = vehicle1.ShowVehicle; //重点！！！！
//一个接受Bus作为参数的委托可以指向一个接受其父类（Vehicle）作为参数的方法
del2(bus1); //但调用时需传入Bus对象，如果传入Vehicle对象会报错（因为signature不匹配）。
//Additional note:you cannot pass vehicle object here
//del2(vehicle1);//error
Mydel2 myDel2 = vehicle1.ShowVehicle;
Mydel2 myDel3 = bus1.ShowBus; //报错
//委托的参数是Vehicle，不能指向一个接受其子类Bus的方法！
//（否则，你使用这个委托时，只知道这个委托接受Vehicle，可能会传入不符合被指向的方法要求的参数）
//委托的返回类型如果是Vehicle的话，它可以指向一个返回类型是其子类Bus的方法（这里未演示）
Console.ReadKey();
}
