BindingManagerBase.Current 屬性
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
當在衍生類別中覆寫時,取得目前物件。
public:
abstract property System::Object ^ Current { System::Object ^ get(); };
public abstract object Current { get; }
public abstract object? Current { get; }
member this.Current : obj
Public MustOverride ReadOnly Property Current As Object
屬性值
表示目前物件的 Object。
範例
下列程式碼範例會在 事件中 BindingManagerBaseCurrentChanged 列印 物件的值 Current 。 此範例假設資料來源是包含 DataTable 名為 CustName
的 DataColumn 。
void Current_Changed( Object^ sender, EventArgs^ /*e*/ )
{
BindingManagerBase^ bm = dynamic_cast<BindingManagerBase^>(sender);
/* Check the type of the Current object. If it is not a
DataRowView, exit the method. */
if ( bm->Current->GetType() != DataRowView::typeid )
return;
// Otherwise, print the value of the column named "CustName".
DataRowView^ drv = dynamic_cast<DataRowView^>(bm->Current);
Console::Write( "CurrentChanged): " );
Console::Write( drv[ "CustName" ] );
Console::WriteLine();
}
private void Current_Changed(object sender, EventArgs e)
{
BindingManagerBase bm = (BindingManagerBase) sender;
/* Check the type of the Current object. If it is not a
DataRowView, exit the method. */
if(bm.Current.GetType() != typeof(DataRowView)) return;
// Otherwise, print the value of the column named "CustName".
DataRowView drv = (DataRowView) bm.Current;
Console.Write("CurrentChanged): ");
Console.Write(drv["CustName"]);
Console.WriteLine();
}
Private Sub Current_Changed(sender As Object, e As EventArgs)
Dim bm As BindingManagerBase = CType(sender, BindingManagerBase)
' Check the type of the Current object. If it is not a
' DataRowView, exit the method.
If bm.Current.GetType() IsNot GetType(DataRowView) Then
Return
End If
' Otherwise, print the value of the column named "CustName".
Dim drv As DataRowView = CType(bm.Current, DataRowView)
Console.Write("CurrentChanged): ")
Console.Write(drv("CustName"))
Console.WriteLine()
End Sub
備註
物件 Current 包含資料來源中目前專案的值。 若要使用目前專案的值,您必須將專案 Type 轉換成 包含 DataSource 之 物件的 。 例如, DataTable 包含 DataRowView 物件。 若要判斷目前物件的類型,請使用 GetType 和 ToString 方法。
注意
DataSource當 是 DataSet 、 DataViewManager 或 DataTable 時,您實際上是系結至 DataView 。 因此,每個 Current 物件都是 DataRowView 物件。