DataTable.RowChanging Gebeurtenis
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Treedt op wanneer een DataRow wijziging plaatsvindt.
public:
event System::Data::DataRowChangeEventHandler ^ RowChanging;
[System.Data.DataSysDescription("DataTableRowChangingDescr")]
public event System.Data.DataRowChangeEventHandler RowChanging;
public event System.Data.DataRowChangeEventHandler RowChanging;
[<System.Data.DataSysDescription("DataTableRowChangingDescr")>]
member this.RowChanging : System.Data.DataRowChangeEventHandler
member this.RowChanging : System.Data.DataRowChangeEventHandler
Public Custom Event RowChanging As DataRowChangeEventHandler
Gebeurtenistype
- Kenmerken
Voorbeelden
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
Opmerkingen
Zie DataTable-gebeurtenissen verwerken voor meer informatie.