DataTable.RowChanging-Ereignis
Tritt ein, wenn eine DataRow geändert wird.
Namespace: System.Data
Assembly: System.Data (in system.data.dll)
Syntax
'Declaration
Public Event RowChanging As DataRowChangeEventHandler
'Usage
Dim instance As DataTable
Dim handler As DataRowChangeEventHandler
AddHandler instance.RowChanging, handler
public event DataRowChangeEventHandler RowChanging
public:
event DataRowChangeEventHandler^ RowChanging {
void add (DataRowChangeEventHandler^ value);
void remove (DataRowChangeEventHandler^ value);
}
/** @event */
public void add_RowChanging (DataRowChangeEventHandler value)
/** @event */
public void remove_RowChanging (DataRowChangeEventHandler value)
JScript unterstützt die Verwendung von Ereignissen, aber nicht die Deklaration von neuen Ereignissen.
Hinweise
Weitere Informationen finden Sie unter Arbeiten mit DataTable-Ereignissen.
Beispiel
Private Sub DataTableRowChanging()
Dim custTable As DataTable = 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
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);
}
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
.NET Compact Framework
Unterstützt in: 2.0, 1.0
Siehe auch
Referenz
DataTable-Klasse
DataTable-Member
System.Data-Namespace