BindingManagerBase.Current 属性
重要
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当在派生类中被重写时，获取当前对象。
public:
abstract property System::Object ^ Current { System::Object ^ get(); };public abstract object Current { get; }public abstract object? Current { get; }member this.Current : objPublic MustOverride ReadOnly Property Current As Object代表当前对象的 Object。
下面的代码示例在 事件中BindingManagerBaseCurrentChanged打印 对象的值Current。 该示例假定数据源是一个 DataTable 包含名为 的 DataColumnCustName。
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
对象 Current 包含数据源中当前项的值。 若要使用当前项的值，必须将项 Type 强制转换为 包含 DataSource的 对象的 。 例如， 包含 DataTableDataRowView 对象。 若要确定当前对象的类型，请使用 GetType 和 ToString 方法。
备注
DataSource当 为 DataSet、 DataViewManager或 DataTable时，实际绑定到 DataView。 因此，每个对象都是 Current 一个 DataRowView 对象。
| 产品 | 版本 |
|---|---|
| .NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
| Windows Desktop | 3.0, 3.1, 5, 6, 7, 8, 9, 10 |
