ListSourceHelper 類別

定義

public ref class ListSourceHelper abstract sealed

public static class ListSourceHelper

type ListSourceHelper = class

Public Class ListSourceHelper

繼承

Object

ListSourceHelper

範例

下列程式碼範例示範實作 方法之資料來源類別 IListSource 的設計模式。

#region Implementation of IDataSource

public virtual DataSourceView GetView(string viewName) {
    if (null == view) {
        view = new SomeDataSourceView(this);
    }
    return view;
}

public virtual ICollection GetViewNames() {
    ArrayList al = new ArrayList(1);
    al.Add(GetView(String.Empty).Name);
    return al as ICollection;
}

event EventHandler IDataSource.DataSourceChanged {
    add {
        ((IDataSource)this).DataSourceChanged += value;
    }
    remove {
        ((IDataSource)this).DataSourceChanged -= value;
    }
}

#endregion
#region Implementation of IListSource

bool IListSource.ContainsListCollection {
    get {
        return ListSourceHelper.ContainsListCollection(this);
    }
}

IList IListSource.GetList() {
    return ListSourceHelper.GetList(this);
}

#endregion

#Region "Implementation of IDataSource"

Public Overridable Function GetView(viewName As String) As DataSourceView Implements IDataSource.GetView
   If view Is Nothing Then
      view = New SomeDataSourceView(Me)
   End If
   Return view
End Function 'GetView


Public Overridable Function GetViewNames() As ICollection Implements IDataSource.GetViewNames
   Dim al As New ArrayList(1)
   al.Add(GetView(String.Empty).Name)
   Return CType( al, ICollection)
End Function 'GetViewNames

Event DataSourceChanged As EventHandler Implements IDataSource.DataSourceChanged

#End Region

#Region "Implementation of IListSource"

ReadOnly Property ContainsListCollection() As Boolean Implements IListSource.ContainsListCollection
   Get
      Return ListSourceHelper.ContainsListCollection(Me)
   End Get
End Property


Function GetList() As IList Implements IListSource.GetList
   Return ListSourceHelper.GetList(Me)
End Function 'IListSource.GetList

#End Region

備註

類別 ListSourceHelper 是公用程式類別，可簡化資料來源控制項的 IListSource 介面實作。 實作 IDataSource 介面但不會擴充 DataSourceControl 類別的資料來源控制項，可以在介面所 IListSource 定義之方法的自有實作中使用靜態 ListSourceHelper 方法。 從 類別延伸的 DataSourceControl 資料來源控制項會自動繼承這些方法實作。

方法

適用於

另請參閱

• IListSource
• DataSourceControl
• DataSourceView