DataTable.RowChanging Händelse
Definition
Viktigt
En del information gäller för förhandsversionen av en produkt och kan komma att ändras avsevärt innan produkten blir allmänt tillgänglig. Microsoft lämnar inga garantier, uttryckliga eller underförstådda, avseende informationen som visas här.
Inträffar när en DataRow ändras.
public:
event System::Data::DataRowChangeEventHandler ^ RowChanging;
public event System.Data.DataRowChangeEventHandler? RowChanging;
public event System.Data.DataRowChangeEventHandler RowChanging;
[System.Data.DataSysDescription("DataTableRowChangingDescr")]
public event System.Data.DataRowChangeEventHandler RowChanging;
member this.RowChanging : System.Data.DataRowChangeEventHandler
[<System.Data.DataSysDescription("DataTableRowChangingDescr")>]
member this.RowChanging : System.Data.DataRowChangeEventHandler
Public Custom Event RowChanging As DataRowChangeEventHandler
Händelsetyp
- Attribut
Exempel
private static void DataTableRowChanging()
{
DataTable custTable = new DataTable("Customers");
// add columns
custTable.Columns.Add("id", typeof(int));
custTable.Columns.Add("name", typeof(string));
custTable.Columns.Add("address", typeof(string));
// set PrimaryKey
custTable.Columns[ "id" ].Unique = true;
custTable.PrimaryKey = new DataColumn[] { custTable.Columns["id"] };
// add a RowChanging event handler for the table.
custTable.RowChanging += new DataRowChangeEventHandler(Row_Changing);
// add ten rows
for(int id=1; id<=10; id++)
{
custTable.Rows.Add(
new object[] { id, string.Format("customer{0}", id),
string.Format("address{0}", id) });
}
custTable.AcceptChanges();
// change the name column in all the rows
foreach(DataRow row in custTable.Rows)
{
row["name"] = string.Format("vip{0}", row["id"]);
}
}
private static void Row_Changing(object sender, DataRowChangeEventArgs e)
{
Console.WriteLine("Row_Changing Event: name={0}; action={1}",
e.Row["name"], e.Action);
}
Private Sub DataTableRowChanging()
Dim custTable As New DataTable("Customers")
' add columns
custTable.Columns.Add("id", Type.GetType("System.Int32"))
custTable.Columns.Add("name", Type.GetType("System.String"))
custTable.Columns.Add("address", Type.GetType("System.String"))
' set PrimaryKey
custTable.Columns("id").Unique = True
custTable.PrimaryKey = New DataColumn() {custTable.Columns("id")}
' add a RowChanging event handler for the table.
AddHandler custTable.RowChanging, _
New DataRowChangeEventHandler(AddressOf Row_Changing)
' add ten rows
Dim id As Integer
For id = 1 To 10
custTable.Rows.Add( _
New Object() {id, String.Format("customer{0}", id), _
String.Format("address{0}", id)})
Next
custTable.AcceptChanges()
' change the name column in all the rows
Dim row As DataRow
For Each row In custTable.Rows
row("name") = String.Format("vip{0}", row("id"))
Next
End Sub
Private Sub Row_Changing(ByVal sender As Object, _
ByVal e As DataRowChangeEventArgs)
Console.WriteLine("Row_Changing Event: name={0}; action={1}", _
e.Row("name"), e.Action)
End Sub
Kommentarer
Mer information finns i Hantera datatabellhändelser.