public DelegateClass()
{
Transformer tr = new Transformer(Square); // 3a) Create delegate instance
Transformer t = Square; // 3b SHORTCUT) Create delegate instance (assigning a method to a delegate variable)
//Square = method group (without brackets or arguments). If overloaded, C# will pick the correct overload based on the signature of the delegate
int resultr = tr.Invoke(3); //4a) Invoke delegate
int result = t(3); // 4b SHORTCUT) Invoke delegate
//Caller invokes the delegate, and then the delegate calls the target method.
//This indirection decouples the caller from the target method.
Console.WriteLine(result); // 9
//Perform method calls in the order they have been added to delegate
Transformer tmulti = null;
tmulti += Square;
tmulti += SquareAndAdd;
tmulti -= Square;
int[] squareNumbers = { 1, 2, 3, 4 };
int[] squareResult = SquareNumber(squareNumbers, Square);
Console.WriteLine(string.Concat(squareResult));
//Delegate types are all incompatible each others
Trans1 tr1 = Square;
Trans2 tr2 = new Trans2(tr1); //It works!
//Trans2 tr2 = tr1; //Doesn't works! Compile-time error
tr2(3);
Console.WriteLine(string.Concat(tr.Method.ToString()));
Console.WriteLine(string.Concat(t.Method.ToString()));
//Possibile assignement with more generic argument type (object rather than string) -> Contravariance
TransObj tobj = new TransObj(SquareObj);
//Possible method return type more specific than delegate return type -> Covariance
TransObjRet tobjret = SquareObjRet;
object stringResult = tobjret();
}
public R(
Single1 single1,
Single2 single2,
Scoped1 scoped1,
Scoped2 scoped2,
Trans1 trans1,
Trans2 trans2,
ScopedFac1 scopedFac1,
ScopedFac2 scopedFac2,
SingleObj1 singleObj1,
SingleObj2 singleObj2
)
{
Single1 = single1;
Single2 = single2;
Scoped1 = scoped1;
Scoped2 = scoped2;
Trans1 = trans1;
Trans2 = trans2;
ScopedFac1 = scopedFac1;
ScopedFac2 = scopedFac2;
SingleObj1 = singleObj1;
SingleObj2 = singleObj2;
}
