我有一个对象集合，我的许多表单（使用WeifenLuo.WinFormsUI.Docking）需要与之交互。
即。如果集合在一个表单中添加（或删除），则其他表单通过刷新其视图进行响应。
显然，观察者模式在这里是一个很好的候选人。但是，我在尝试在我的程序中实现这个问题时遇到了问题。
首先，最好为我的集合创建一个观察者类，如下所示：
public class DataCollectionObserver : Form
{
internal static void DataCollectionRegister(DataCollection dataCollection)
{
dataCollection.ImageAdded += new EventHandler(dataAdded);
dataCollection.ImageRemoved += new EventHandler(dataRemoved);
dataCollection.ImageIndexChanged += new EventHandler(dataIndexChanged);
dataCollection.ImageListCleared += new EventHandler(dataListCleared);
}
internal static void DataCollectionUnRegister(DataCollection dataCollection)
{
dataCollection.ImageAdded -= new EventHandler(dataAdded);
dataCollection.ImageRemoved -= new EventHandler(dataRemoved);
dataCollection.ImageIndexChanged -= new EventHandler(dataIndexChanged);
dataCollection.ImageListCleared -= new EventHandler(dataListCleared);
}
internal static void dataAdded(object sender, EventArgs e) {}
internal static void dataRemoved(object sender, EventArgs e) {}
internal static void dataIndexChanged(object sender, EventArgs e) {}
internal static void dataListCleared(object sender, EventArgs e) {}
}
然后覆盖子类表单中的基本事件处理程序？
但是，我不能这样做并使用WeifenLuo.WinFormsUI.Docking库......
好吧，我可以让DataCollectionObserver从WeifenLuo.WinFormsUI.Docking继承DockContent，但这会产生一种情况，我需要有两个DataCollectionObserver类 - 一个继承Form，另一个继承DockContent： - [ 或者，我可以使DataCollectionObserver成为一个接口，但仍然留下了重复的代码......
那么，有没有人在这里提出建议？我是否遗漏了一些显而易见的事情，或者为了简单起见，这是否必须重复执行代码？
修改：//
我在表单中收到通知时遇到问题。事实上，整个事情现在正在发挥作用。我问的原因是因为整个事情“闻起来”是由于我在这四种不同形式的代码块复制和粘贴，我订阅了集合事件并取消订阅Form.Closing（）。
我想要做的是在一个地方实现我复制并粘贴到这四个表单的行为，并让应该收到集合更改通知的表单根据需要实现该行为。
希望让事情更清楚？
FWIW，这是我的收藏类：
using System;
using System.Collections;
using System.Reflection;
namespace MyNameSpace.Collections
{
/// <summary>
/// Generic Collection of Objects with Events
/// </summary>
public class CollectionWithEvents<T> : CollectionBase
{
public bool SuppressEventNotification
{
get;
set;
}
public CollectionWithEvents()
{
SuppressEventNotification = false;
}
#region Events
/// <summary>
/// Raises before an item is added to the list.
/// </summary>
public event EventHandler<ItemEventArgs<T>> BeforeItemAdded;
/// <summary>
/// Raises when an item is added to the list.
/// </summary>
public event EventHandler<ItemEventArgs<T>> ItemAdded;
/// <summary>
/// Raises before a collection of items is added to the list.
/// </summary>
public event EventHandler<ItemsEventArgs<T>> BeforeItemsAdded;
/// <summary>
/// Raises when a collection of items is added to the list.
/// </summary>
public event EventHandler<ItemsEventArgs<T>> ItemsAdded;
/// <summary>
/// Raises before an item is changed in the list.
/// </summary>
public event EventHandler<ItemEventArgs<T>> BeforeItemChanged;
/// <summary>
/// Raises when an item is changed in the list.
/// </summary>
public event EventHandler<ItemEventArgs<T>> ItemChanged;
/// <summary>
/// Raises before an item is removed from the list.
/// </summary>
public event EventHandler<ItemEventArgs<T>> BeforeItemRemoved;
/// <summary>
/// Raises when an item is removed from the list.
/// </summary>
public event EventHandler<ItemEventArgs<T>> ItemRemoved;
/// <summary>
/// Raises when the items are cleared from the list.
/// </summary>
public event EventHandler<EventArgs> ItemsCleared;
#endregion
public T this[int index]
{
get { return (T)this.List[index]; }
set
{
if (!SuppressEventNotification)
{
OnBeforeItemChanged(this, new ItemEventArgs<T>(value));
}
this.List[index] = value;
if (!SuppressEventNotification)
{
OnItemChanged(this, new ItemEventArgs<T>(value));
}
}
}
public int Add(T item)
{
if (!SuppressEventNotification)
{
OnBeforeItemAdded(this, new ItemEventArgs<T>(item));
}
int retValue = this.List.Add(item);
if (!SuppressEventNotification)
{
OnItemAdded(this, new ItemEventArgs<T>(item));
}
return retValue;
}
public void AddRange(Collection<T> collection)
{
T[] tmp = new T[collection.Count];
collection.CopyTo(tmp, 0);
AddRange(tmp);
}
public void AddRange(T[] collection)
{
if (!SuppressEventNotification)
{
OnBeforeItemsAdded(this, new ItemsEventArgs<T>(collection));
}
this.AddRange(collection);
if (!SuppressEventNotification)
{
OnItemsAdded(this, new ItemsEventArgs<T>(collection));
}
}
public bool Contains(T item)
{
return this.List.Contains(item);
}
public void CopyTo(Array array, int index)
{
this.List.CopyTo(array, index);
}
public int IndexOf(T item)
{
return this.List.IndexOf(item);
}
public void Insert(int index, T item)
{
this.List.Insert(index, item);
}
public void Remove(T item)
{
if (!SuppressEventNotification)
{
OnBeforeItemRemoved(this, new ItemEventArgs<T>(item));
}
T tmp = (T)item;
this.List.Remove(item);
if (!SuppressEventNotification)
{
OnItemRemoved(this, new ItemEventArgs<T>(tmp));
}
tmp = default(T);
}
public void Sort(string Property, Common.SortOrder Order)
{
Common.GenericComparer genericComparer = new Common.GenericComparer(Property, Order);
this.InnerList.Sort(genericComparer);
}
#region Event Methods
/// <summary>
/// Raised before an Item is added to the list.
/// </summary>
/// <param name="sender">object</param>
/// <param name="e">ItemEventArgs</param>
protected virtual void OnBeforeItemAdded(object sender, ItemEventArgs<T> e)
{
if (BeforeItemAdded != null)
{
BeforeItemAdded(sender, e);
}
}
/// <summary>
/// Raised when an Item is added to the list.
/// </summary>
/// <param name="sender"></param>
/// <param name="e">ItemEventArgs</param>
protected virtual void OnItemAdded(object sender, ItemEventArgs<T> e)
{
if (ItemAdded != null)
{
ItemAdded(sender, e);
}
}
/// <summary>
/// Raised before a collection of Items is added to the list.
/// </summary>
/// <param name="sender">object</param>
/// <param name="e">ItemEventArgs</param>
protected virtual void OnBeforeItemsAdded(object sender, ItemsEventArgs<T> e)
{
if (BeforeItemsAdded != null)
{
BeforeItemsAdded(sender, e);
}
}
/// <summary>
/// Raised when a collection of Items is added to the list.
/// </summary>
/// <param name="sender"></param>
/// <param name="e">ItemEventArgs</param>
protected virtual void OnItemsAdded(object sender, ItemsEventArgs<T> e)
{
if (ItemsAdded != null)
{
ItemsAdded(sender, e);
}
}
/// <summary>
/// Raised before an Item is changed to the list.
/// </summary>
/// <param name="sender"></param>
/// <param name="e">GenericItemEventArgs</param>
protected virtual void OnBeforeItemChanged(object sender, ItemEventArgs<T> e)
{
if (BeforeItemChanged != null)
{
BeforeItemChanged(sender, e);
}
}
/// <summary>
/// Raised when an Item is changed to the list.
/// </summary>
/// <param name="sender"></param>
/// <param name="e">ItemEventArgs</param>
protected virtual void OnItemChanged(object sender, ItemEventArgs<T> e)
{
if (ItemChanged != null)
{
ItemChanged(sender, e);
}
}
/// <summary>
/// Raised before an Item is removed from the list.
/// </summary>
/// <param name="sender"></param>
/// <param name="e">ItemEventArgs</param>
protected virtual void OnBeforeItemRemoved(object sender, ItemEventArgs<T> e)
{
if (BeforeItemRemoved != null)
{
BeforeItemRemoved(sender, e);
}
}
/// <summary>
/// Raised when an Item is removed from the list.
/// </summary>
/// <param name="sender">object</param>
/// <param name="e">ItemEventsArgs</param>
protected virtual void OnItemRemoved(object sender, ItemEventArgs<T> e)
{
if (ItemRemoved != null)
{
ItemRemoved(sender, e);
}
}
/// <summary>
/// Raised when the Items are cleared from this list.
/// </summary>
/// <param name="sender">object</param>
/// <param name="e">EventArgs</param>
protected virtual void OnItemsCleared(object sender, EventArgs e)
{
if (ItemsCleared != null)
{
ItemsCleared(sender, e);
}
}
#endregion
}
public class ItemEventArgs<T> : EventArgs
{
/// <summary>
/// Item
/// </summary>
public T Item { get; private set; }
/// <summary>
/// Default constructor
/// </summary>
/// <param name="Item"></param>
public ItemEventArgs(T Item)
{
this.Item = Item;
}
}
public class ItemsEventArgs<T> : EventArgs
{
/// <summary>
/// Items
/// </summary>
public T[] Items { get; private set; }
/// <summary>
/// Default constructor
/// </summary>
/// <param name="Items"></param>
public ItemsEventArgs(T[] Items)
{
this.Items = Items;
}
}
}
答案 0 :(得分：2)
我可能弄错了。但你可以这样做，你的继承问题就不存在了。我将尝试举一个简单的例子：
你的集合类可能就是这样：
public class MyCollection
{
IList<string> MyList { get; set; }
public event EventHandler<StringEventArgs> OnAdded;
public event EventHandler<StringEventArgs> OnRemoved;
public MyCollection()
{
MyList = new List<string>();
}
public void Add(string s)
{
MyList.Add(s);
if (OnAdded != null)
OnAdded(this, new StringEventArgs() { StringAddedOrRemoved = s });
}
public void Remove(string s)
{
MyList.Remove(s);
if (OnRemoved != null)
OnRemoved(this, new StringEventArgs() { StringAddedOrRemoved = s });
}
}
带有两个自定义EventHandler的非常简单的类：
public class StringEventArgs : EventArgs
{
public string StringAddedOrRemoved;
public override string ToString()
{
return StringAddedOrRemoved;
}
}
这里没有什么难以理解的，然后基于这三种形式，您可以通过这种方式使用表单。
第一个按钮有两个按钮与集合进行交互，并创建两个将观察您的集合的表单：
public partial class Form1 : Form
{
public static MyCollection collection;
public Form1()
{
InitializeComponent();
collection = new MyCollection();
Form2 form2 = new Form2();
form2.Show();
Form3 form3 = new Form3();
form3.Show();
collection.OnAdded += form2.MyCollectionAdded;
collection.OnRemoved += form2.MyCollectionRemoved;
collection.OnAdded += form3.MyCollectionAdded;
collection.OnRemoved += form3.MyCollectionRemoved;
}
private void Add_Click(object sender, EventArgs e)
{
collection.Add("test add");
}
private void button1_Click(object sender, EventArgs e)
{
collection.Remove("test add");
}
}
该集合将链接到将在此处观察到的表单的每个函数：
collection.OnAdded += form2.MyCollectionAdded;
collection.OnRemoved += form2.MyCollectionRemoved;
collection.OnAdded += form3.MyCollectionAdded;
collection.OnRemoved += form3.MyCollectionRemoved;
所以我们需要实现这些形式：
public partial class Form2 : Form
{
public string Name { get; set; }
public bool Flag { get; set; }
public Form2()
{
InitializeComponent();
}
public void MyCollectionAdded(object sender, StringEventArgs e)
{
//Some action
Flag = true;
label1.Text = string.Format("{0} has added {1} to its list, flag={2}", Name, e.StringAddedOrRemoved, Flag);
}
public void MyCollectionRemoved(object sender, StringEventArgs e)
{
//Some action
Flag = false;
label1.Text = string.Format("{0} has removed {1} from its list, flag={2}", Name, e.StringAddedOrRemoved, Flag);
}
}
我从Form继承我的东西，但它可以从你想要的任何实际上继承。如果你想在不同的形式之间共享一些代码，可以考虑静态类中的辅助函数，或者任何可能适合你需要的模式。
希望它有所帮助，而且我并没有完全超出范围！
[编辑]哎呀没有看到编辑，对不起朋友！[/编辑]
答案 1 :(得分：1)
如果它是＆gt; = 3.5，您正在使用哪个.net版本，您可以使用ObservableCollection来实现您正在做的事情
答案 2 :(得分：1)
框架中有一个'ObservableCollection'，仅用于此类事情。请参阅here。