C# 使用泛型类型扩展集合
我的目标是扩展集合对象以支持在集合中添加、更新或删除项时标记。提供了一个扩展特定类型的示例(示例2)。我希望保持它的通用性,这样我就不必为我拥有的每个集合嵌入一个新类 以下是我到目前为止的情况:C# 使用泛型类型扩展集合,c#,.net,C#,.net,我的目标是扩展集合对象以支持在集合中添加、更新或删除项时标记。提供了一个扩展特定类型的示例(示例2)。我希望保持它的通用性,这样我就不必为我拥有的每个集合嵌入一个新类 以下是我到目前为止的情况: public class ChangedEventArgs<T> : EventArgs { public readonly T ChangedItem; public readonly T ReplacedWith; public readonly ChangeTy
public class ChangedEventArgs<T> : EventArgs
{
public readonly T ChangedItem;
public readonly T ReplacedWith;
public readonly ChangeType ChangeType;
public ChangedEventArgs(ChangeType change, T item, T replacement)
{
ChangeType = change;
ChangedItem = item;
ReplacedWith = replacement;
}
}
public enum ChangeType
{
Added,
Removed,
Replaced,
Cleared
};
class CollectionChangeTracked<T> : Collection<T>
{
public event EventHandler<ChangedEventArgs<T>> Changed;
protected override void InsertItem<TParam>(int index, TParam newItem)
{
base.InsertItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(ChangeType.Added, newItem, null));
}
}
protected override void SetItem<TParam>(int index, TParam newItem)
{
string replaced = Items[index];
base.SetItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs(ChangeType.Replaced, replaced, newItem));
}
}
protected override void RemoveItem<TParam>(int index)
{
TParam removedItem = Items[index];
base.RemoveItem(index);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(ChangeType.Removed, removedItem, null));
}
}
protected override void ClearItems()
{
base.ClearItems();
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs(ChangeType.Cleared, null, null));
}
}
}
公共类ChangedEventArgs:EventArgs
{
公共只读T ChangedItem;
公共只读T替换为;
公共只读ChangeType ChangeType;
公共ChangedEventArgs(变更类型变更、T项、T替换)
{
变更类型=变更;
ChangedItem=项目;
替换为=替换;
}
}
公共枚举更改类型
{
补充,
远离的,
取代,
变明朗
};
类CollectionChangeTracked:集合
{
公共事件事件处理程序已更改;
受保护的覆盖无效插入项(int索引,TParam newItem)
{
base.InsertItem(索引,newItem);
EventHandler temp=已更改;
如果(温度!=null)
{
temp(this,newchangedventargs(ChangeType.Added,newItem,null));
}
}
受保护的覆盖无效SetItem(int索引,TParam newItem)
{
替换的字符串=项[索引];
base.SetItem(索引,newItem);
EventHandler temp=已更改;
如果(温度!=null)
{
临时(此,新ChangedEventArgs(ChangeType.Replaced,Replaced,newItem));
}
}
受保护的覆盖void removietem(int索引)
{
TParam removedItem=项目[索引];
基本删除项(索引);
EventHandler temp=已更改;
如果(温度!=null)
{
temp(这个,新的ChangedEventArgs(ChangeType.Removed,removedItem,null));
}
}
受保护的覆盖无效ClearItems()
{
base.ClearItems();
EventHandler temp=已更改;
如果(温度!=null)
{
temp(这个,新的ChangedEventArgs(ChangeType.Cleared,null,null));
}
}
}
问题:
我在以下行收到错误:base.InsertItem(index,newItem)
它说我有无效的论点,但仅此而已。SetItem和RemoveItem中存在相同问题
更新了编译以下内容的代码:
public class ChangedEventArgs<T> : EventArgs
{
public readonly T ChangedItem;
public readonly T? ReplacedWith;
public readonly ChangeType ChangeType;
public ChangedEventArgs(ChangeType change, T item, T? replacement)
{
ChangeType = change;
ChangedItem = item;
ReplacedWith = replacement;
}
}
public enum ChangeType
{
Added,
Removed,
Replaced,
Cleared
};
class CollectionChangeTracked<T> : Collection<T>
{
public event EventHandler<ChangedEventArgs<T>> Changed;
protected override void InsertItem(int index, T newItem)
{
base.InsertItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
temp(this, new ChangedEventArgs<T>(ChangeType.Added, newItem, default(T)));
}
protected override void SetItem(int index, T newItem)
{
T replaced = Items[index];
base.SetItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
temp(this, new ChangedEventArgs<T>(ChangeType.Replaced, replaced, newItem));
}
protected override void RemoveItem(int index)
{
T removedItem = Items[index];
base.RemoveItem(index);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
temp(this, new ChangedEventArgs<T>(ChangeType.Removed, removedItem, null));
}
protected override void ClearItems()
{
base.ClearItems();
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
temp(this, new ChangedEventArgs<T>(ChangeType.Cleared, null, null));
}
公共类ChangedEventArgs:EventArgs
{
公共只读T ChangedItem;
公共只读T?替换为;
公共只读ChangeType ChangeType;
公共ChangedEventArgs(变更类型变更、T项、T替换)
{
变更类型=变更;
ChangedItem=项目;
替换为=替换;
}
}
公共枚举更改类型
{
补充,
远离的,
取代,
变明朗
};
类CollectionChangeTracked:集合
{
公共事件事件处理程序已更改;
受保护的重写void插入项(int索引,T newItem)
{
base.InsertItem(索引,newItem);
EventHandler temp=已更改;
如果(温度!=null)
temp(这个,新的ChangedEventArgs(ChangeType.Added,newItem,默认值(T));
}
受保护的覆盖无效SetItem(int索引,T newItem)
{
T替换=项目[索引];
base.SetItem(索引,newItem);
EventHandler temp=已更改;
如果(温度!=null)
临时(此,新ChangedEventArgs(ChangeType.Replaced,Replaced,newItem));
}
受保护的覆盖void removietem(int索引)
{
T removedItem=项目[索引];
基本删除项(索引);
EventHandler temp=已更改;
如果(温度!=null)
temp(这个,新的ChangedEventArgs(ChangeType.Removed,removedItem,null));
}
受保护的覆盖无效ClearItems()
{
base.ClearItems();
EventHandler temp=已更改;
如果(温度!=null)
temp(这个,新的ChangedEventArgs(ChangeType.Cleared,null,null));
}
我想这会有所帮助,但我猜你的问题有点含糊不清,没有完成
public class ChangedEventArgs<T> : EventArgs
{
public readonly T ChangedItem;
public readonly T ReplacedWith;
public readonly ChangeType ChangeType;
public ChangedEventArgs(ChangeType change, T item, T replacement)
{
ChangeType = change;
ChangedItem = item;
ReplacedWith = replacement;
}
}
公共类ChangedEventArgs:EventArgs
{
公共只读T ChangedItem;
公共只读T替换为;
公共只读ChangeType ChangeType;
公共ChangedEventArgs(变更类型变更、T项、T替换)
{
变更类型=变更;
ChangedItem=项目;
替换为=替换;
}
}
@daveL完全正确,您需要的是一个通用事件参数:
public class ChangedEventArgs<T> : EventArgs
{
public readonly T ChangedItem;
public readonly T ReplacedWith;
public readonly ChangeType ChangeType;
public ChangedEventArgs(ChangeType change, T item, T replacement)
{
ChangeType = change;
ChangedItem = item;
ReplacedWith = replacement;
}
}
然后,您的单个方法,而不是将类型重新定义为TParam
,应该使用在类级别定义的T
:
protected override void InsertItem(int index, T newItem)
{
base.InsertItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
// Added <T> after ChangedEventArgs
temp(this, new ChangedEventArgs<T>(ChangeType.Added, newItem, default(T)));
}
}
protected override void InsertItem(int index,T newItem)
{
base.InsertItem(索引,newItem);
EventHandler temp=已更改;
如果(温度!=null)
{
//在ChangedEventArgs之后添加
temp(这个,新的ChangedEventArgs(ChangeType.Added,newItem,默认值(T));
}
}
实例:您必须将ChangedEventArgs类定义为泛型 试试这个:
public class ChangedEventArgs<T> : EventArgs
{
public readonly T ChangedItem;
public readonly ChangeType ChangeType;
public readonly T ReplacedWith;
public ChangedEventArgs(ChangeType change, T item,
T replacement)
{
ChangeType = change;
ChangedItem = item;
ReplacedWith = replacement;
}
}
public enum ChangeType
{
Added,
Removed,
Replaced,
Cleared
};
class CollectionChangeTracked<T> : Collection<T>
{
public event EventHandler<ChangedEventArgs<T>> Changed;
protected override void InsertItem(int index, T newItem)
{
base.InsertItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(
ChangeType.Added, newItem, default(T)));
}
}
protected override void SetItem(int index, T newItem)
{
T replaced = Items[index];
base.SetItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(
ChangeType.Replaced, replaced, newItem));
}
}
protected override void RemoveItem(int index)
{
T removedItem = Items[index];
base.RemoveItem(index);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(
ChangeType.Removed, removedItem, default(T)));
}
}
protected override void ClearItems()
{
base.ClearItems();
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(
ChangeType.Cleared, default(T), default(T)));
}
}
}
公共类ChangedEventArgs:EventArgs
{
公共只读T ChangedItem;
公共只读ChangeType ChangeType;
公共只读T替换为;
公共ChangedEventArgs(变更类型变更,T项,
(T更换)
{
变更类型=变更;
ChangedItem=项目;
替换为=替换;
}
}
公共枚举更改类型
{
补充,
远离的,
取代,
变明朗
};
类CollectionChangeTracked:集合
{
公共事件事件处理程序已更改;
受保护的重写void插入项(int索引,T newItem)
{
base.InsertItem(索引,newItem);
EventHandler temp=已更改;
如果(温度!=null)
{
临时工(此,新变更)(
ChangeType.Added,newItem,默认值(T));
}
}
受保护的覆盖无效SetItem(int索引,T newItem)
{
T替换=项目[索引];
base.SetItem(索引,newItem);
EventHandler temp=已更改;
如果(温度!=null)
{
临时工(此,新变更)
public class ChangedEventArgs<T> : EventArgs
{
public readonly T ChangedItem;
public readonly ChangeType ChangeType;
public readonly T ReplacedWith;
public ChangedEventArgs(ChangeType change, T item,
T replacement)
{
ChangeType = change;
ChangedItem = item;
ReplacedWith = replacement;
}
}
public enum ChangeType
{
Added,
Removed,
Replaced,
Cleared
};
class CollectionChangeTracked<T> : Collection<T>
{
public event EventHandler<ChangedEventArgs<T>> Changed;
protected override void InsertItem(int index, T newItem)
{
base.InsertItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(
ChangeType.Added, newItem, default(T)));
}
}
protected override void SetItem(int index, T newItem)
{
T replaced = Items[index];
base.SetItem(index, newItem);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(
ChangeType.Replaced, replaced, newItem));
}
}
protected override void RemoveItem(int index)
{
T removedItem = Items[index];
base.RemoveItem(index);
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(
ChangeType.Removed, removedItem, default(T)));
}
}
protected override void ClearItems()
{
base.ClearItems();
EventHandler<ChangedEventArgs<T>> temp = Changed;
if (temp != null)
{
temp(this, new ChangedEventArgs<T>(
ChangeType.Cleared, default(T), default(T)));
}
}
}