program.cs

这是.net2005学习不可缺少的教程

using System;

class InventoryChangeEventArgs : EventArgs
{
    public InventoryChangeEventArgs(string sku, int change)
    {
        this.sku = sku;
        this.change = change;
    }

    string sku;
    public string Sku
    {
        get
        {
            return sku;
        }
    }

    int change;
    public int Change
    {
        get
        {
            return change;
        }
    }
}

class InventoryManager // Publisher.
{
    public delegate void InventoryChangeEventHandler
        (object source, InventoryChangeEventArgs e);
    public event InventoryChangeEventHandler OnInventoryChangeHandler;



    public void UpdateInventory(string sku, int change)
    {
        if (0 == change)
            return; // No update on null change.

        // Code to update database would go here.

        InventoryChangeEventArgs e = new
            InventoryChangeEventArgs(sku, change);

        if (OnInventoryChangeHandler != null)
            OnInventoryChangeHandler(this, e);
    }
}

class InventoryWatcher // Subscriber.
{
    public InventoryWatcher(InventoryManager inventoryManager)
    {
        this.inventoryManager = inventoryManager;
        inventoryManager.OnInventoryChangeHandler += new
InventoryManager.InventoryChangeEventHandler(OnInventoryChange);
    }
    void OnInventoryChange(object source, InventoryChangeEventArgs e)
    {
        int change = e.Change;
        Console.WriteLine("Part '{0}' was {1} by {2} units",
            e.Sku,
            change > 0 ? "increased" : "decreased",
            Math.Abs(e.Change));
    }
    InventoryManager inventoryManager;
}

class Events1App
{
    public static void Main()
    {
        InventoryManager inventoryManager =
            new InventoryManager();

        InventoryWatcher inventoryWatch =
            new InventoryWatcher(inventoryManager);

        inventoryManager.UpdateInventory("111 006 116", -2);
        inventoryManager.UpdateInventory("111 005 383", 5);
    }
}