25. Delegate (2)

1. In the previous section, the delegate is declared using static methods. In this section, the delegate is declared using dynamic methods to make it more flexible.

Code

 Namespace _ 25. Delegate _ 2 _
{

Public partial class Form1: Form
{
Public Form1 ()
{
InitializeComponent ();
}

Private void Form1_Load (object sender, EventArgs e)
{
Man xw = new Man ("John ");
Man xl = new Man ("Xiao Li ");
Man xz = new Man ("Xiao Zhao ");
EatDelegate a = new EatDelegate (xw. eat );
EatDelegate s = new EatDelegate (xl. eat );
EatDelegate d = new EatDelegate (xz. eat );
EatDelegate eatChain = null;
MessageBox. Show ("three-person open Part ");
EatChain = a + s + d;
EatChain ("watermelon ");
}
}
Delegate void EatDelegate (string food );
Class Man
{
Private string name;
Public Man (string name)
{
This. name = name;
}
Public void eat (string food)
{
MessageBox. Show (name + "eat" + food );
}
}
}

2. Next, the above contains multiple parameters.

 

Code

 Namespace _ 25. Delegate _ 2 _
{

Public partial class Form1: Form
{
Public Form1 ()
{
InitializeComponent ();
}
Private void Form1_Load (object sender, EventArgs e)
{
Man xw = new Man ("John ");
Man xl = new Man ("Xiao Li ");
Man xz = new Man ("Xiao Zhao ");
EatDelegate a = new EatDelegate (xw. eat );
EatDelegate s = new EatDelegate (xl. eat );
EatDelegate d = new EatDelegate (xz. eat );
EatDelegate eatChain = null;
MessageBox. Show ("three-person open Part ");
EatTogether ("watermelon", a, s, d );
MessageBox. Show ("xw goes out ");
EatTogether ("grape", s, d );
MessageBox. Show ("xw comes here ");
EatTogether ("orange", a, s, d );
EatTogether (null, null );
}
Static void eatTogether (string food, params EatDelegate [] values)
{
If (values = null)
{
MessageBox. Show ("Party is over! ");
}
Else
{
EatDelegate eatChain = null;
Foreach (EatDelegate ed in values)
EatChain + = ed;
EatChain (food );
MessageBox. Show ("");
}
}
}
Delegate void EatDelegate (string food );
Class Man
{
Private string name;
Public Man (string name)
{
This. name = name;
}
Public void eat (string food)
{
MessageBox. Show (name + "eat" + food );
}
}
}