DataTable.ColumnChanged Event
Definition
Important
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Occurs after a value has been changed for the specified DataColumn in a DataRow.
public:
event System::Data::DataColumnChangeEventHandler ^ ColumnChanged;
public event System.Data.DataColumnChangeEventHandler? ColumnChanged;
public event System.Data.DataColumnChangeEventHandler ColumnChanged;
[System.Data.DataSysDescription("DataTableColumnChangedDescr")]
public event System.Data.DataColumnChangeEventHandler ColumnChanged;
member this.ColumnChanged : System.Data.DataColumnChangeEventHandler
[<System.Data.DataSysDescription("DataTableColumnChangedDescr")>]
member this.ColumnChanged : System.Data.DataColumnChangeEventHandler
Public Custom Event ColumnChanged As DataColumnChangeEventHandler
Event Type
- Attributes
Examples
private static void DataTableColumnChanged()
{
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 ColumnChanged event handler for the table.
custTable.ColumnChanged += new
DataColumnChangeEventHandler(Column_Changed );
// 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 Column_Changed(object sender, DataColumnChangeEventArgs e )
{
Console.WriteLine("Column_Changed Event: name={0}; Column={1}; original name={2}",
e.Row["name"], e.Column.ColumnName, e.Row["name", DataRowVersion.Original]);
}
Private Shared Sub DataTableColumnChanged()
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 ColumnChanged event handler for the table.
AddHandler custTable.ColumnChanged, _
New DataColumnChangeEventHandler(AddressOf Column_Changed )
' 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 Shared Sub Column_Changed(sender As Object, _
e As DataColumnChangeEventArgs)
Console.WriteLine("Column_Changed Event: name={0}; Column={1}; original name={2}", _
e.Row("name"), e.Column.ColumnName, e.Row("name", DataRowVersion.Original))
End Sub
Remarks
For more information, see Handling DataTable Events.
Applies to
See also
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