There is this thing in C# called a delegate, which is going to be crucial to build interactions between our objects. What's a delegate, you ask? Good question. A delegate is a pointer to a method. What's that mean? Just like you can pass variable by reference, you can pass a reference to a method. Let me give you an example.
Let's say we have a class with two methods that have the same signature (same return type and same parameter configuration).
public class MyObject
{
public int Add(int param1, int param2)
{
return param1 + param2;
}
public int Multiply(int param1, int param2)
{
return param1 * param2;
}
} We can point to either of the methods in our class by using a delegate declared as follows:
public delegate int MyMethodDelegate(int param1, int param2);
Now, if we have another class and want to execute either of the methods in MyObject, we can do it through the delegate as in the "Do()" method in the class below. As a matter of fact, we can pass any method with the same signature (not JUST the methods in MyObject). Check out the MySecondObject.Subtract() method.
public class MySecondObject
{
MyObject obj;
int a, b;
public MySecondObject()
{
a=4;
b=5;
obj = new MyObject();
}
public int Do(string pMethod)
{
MyMethodDelegate del = null;
switch(pMethod)
{
case"Add":
del = new MyMethodDelegate(obj.Add);
break;
case"Multiply":
del = new MyMethodDelegate(obj.Multiply);
break;
case "Subtract":
del = new MyMethodDelegate(this.Subtract);
break;
}
if(null == del) throw new Exception("Not a valid call");
return del(a,b);
}
public int Subtract(int param1, int param2)
{
return param1 - param2;
}
}
Hopefully this gives you a better idea of what delegates are and how they are implemented.
Happy coding,