DataColumnCollection.CollectionChanged 事件
定義
發生於資料行集合變更時 (藉由加入或移除資料行)。Occurs when the columns collection changes, either by adding or removing a column.
public:
event System::ComponentModel::CollectionChangeEventHandler ^ CollectionChanged;
public event System.ComponentModel.CollectionChangeEventHandler CollectionChanged;
member this.CollectionChanged : System.ComponentModel.CollectionChangeEventHandler
Public Custom Event CollectionChanged As CollectionChangeEventHandler
範例
下列範例會加入 CollectionChanged 事件的事件處理常式。The following example adds an event handler for the CollectionChanged event.
private void AddEventHandler(DataTable table)
{
DataColumnCollection columns = table.Columns;
columns.CollectionChanged += new
System.ComponentModel.CollectionChangeEventHandler(
ColumnsCollection_Changed);
}
private void ColumnsCollection_Changed(object sender,
System.ComponentModel.CollectionChangeEventArgs e)
{
DataColumnCollection columns =
(DataColumnCollection) sender;
Console.WriteLine("ColumnsCollectionChanged: "
+ columns.Count);
}
Private Sub AddEventHandler(table As DataTable)
Dim columns As DataColumnCollection = table.Columns
AddHandler columns.CollectionChanged, _
AddressOf ColumnsCollection_Changed
End Sub
Private Sub ColumnsCollection_Changed _
(sender As Object, e As System.ComponentModel. _
CollectionChangeEventArgs)
Dim columns As DataColumnCollection = _
CType(sender, DataColumnCollection)
Console.WriteLine("ColumnsCollectionChanged: " _
& columns.Count.ToString())
End Sub
備註
Contains使用和CanRemove方法來判斷資料行是否存在,以及是否可以移除。Use the Contains and CanRemove methods to determine whether a column exists and can be removed.