DataRow.RejectChanges Metodo

Definizione

Rifiuta tutte le modifiche apportate alla riga sin dall'ultima chiamata al metodo AcceptChanges().Rejects all changes made to the row since AcceptChanges() was last called.

public:
 void RejectChanges();
public void RejectChanges ();
member this.RejectChanges : unit -> unit
Public Sub RejectChanges ()

Eccezioni

La riga non appartiene alla tabella.The row does not belong to the table.

Esempio

Nell'esempio seguente viene creata una semplice DataTable con due colonne e 10 righe.The following example creates a simple DataTable with 2 columns and 10 rows. Dopo DataRow l'eliminazione di diversi elementi con Delete il metodo, una delle righe viene annullata mediante la chiamata a RejectChanges .After several DataRow items are deleted with the Delete method, one of the rows is undeleted by invoking RejectChanges.

private void DemonstrateDeleteRow()
{
    // Create a simple DataTable with two columns and ten rows.
    DataTable table = new DataTable("table");
    DataColumn idColumn = new DataColumn("id",
        Type.GetType("System.Int32"));
    idColumn.AutoIncrement=true;
    DataColumn itemColumn = new DataColumn("item",
        Type.GetType("System.String"));
    table.Columns.Add(idColumn);
    table.Columns.Add(itemColumn);

    // Add ten rows.
    DataRow newRow;

    for(int i = 0; i <10; i++)
    {
        newRow = table.NewRow();
        newRow["item"] = "Item " + i;
        table.Rows.Add(newRow);
    }
    table.AcceptChanges();

    DataRowCollection itemColumns = table.Rows;
    itemColumns[0].Delete();
    itemColumns[2].Delete();
    itemColumns[3].Delete();
    itemColumns[5].Delete();
    Console.WriteLine(itemColumns[3].RowState.ToString());

    // Reject changes on one deletion.
    itemColumns[3].RejectChanges();

    // Change the value of the column so it stands out.
    itemColumns[3]["item"] = "Deleted, Undeleted, Edited";

    // Accept changes on others.
    table.AcceptChanges();

    // Print the remaining row values.
    foreach(DataRow row in table.Rows)
    {
        Console.WriteLine(row[0] + "\table" + row[1]);
    }
}
 Private Sub DemonstrateDeleteRow()
     ' Create a simple DataTable with two columns and ten rows.
     Dim table As New DataTable("table")
     Dim idColumn As New DataColumn("id", Type.GetType("System.Int32"))
     idColumn.AutoIncrement = True
     Dim itemColumn As New DataColumn("item", Type.GetType("System.String"))
     table.Columns.Add(idColumn)
     table.Columns.Add(itemColumn)

     ' Add ten rows.
     Dim newRow As DataRow
     
     Dim i As Integer
     For i = 0 To 9
         newRow = table.NewRow()
         newRow("item") = "Item " & i.ToString()
         table.Rows.Add(newRow)
     Next i
     table.AcceptChanges()

     Dim itemColumns As DataRowCollection = table.Rows
     itemColumns(0).Delete()
     itemColumns(2).Delete()
     itemColumns(3).Delete()
     itemColumns(5).Delete()
     Console.WriteLine(itemColumns(3).RowState.ToString())

     ' Reject changes on one deletion.
     itemColumns(3).RejectChanges()

     ' Change the value of the column so it stands out.
     itemColumns(3)("item") = "Deleted, Undeleted, Edited"

     ' Accept changes on others.
     table.AcceptChanges()

     ' Print the remaining row values.
     Dim row As DataRow
     For Each row In  table.Rows
         Console.WriteLine(row(0).ToString() & ControlChars.Tab _
            & row(1).ToString())
     Next row
End Sub

Commenti

Quando si chiama il RejectChanges metodo, il CancelEdit metodo viene chiamato in modo implicito per annullare le modifiche.When you call the RejectChanges method, the CancelEdit method is implicitly called to cancel any edits. Se RowState viene eliminato o modificato, la riga viene ripristinata ai valori precedenti e RowState diventa invariata.If RowState is deleted or modified, the row reverts to its previous values, and RowState becomes unchanged. Se RowState viene aggiunto, la riga viene rimossa.If the RowState is added, the row is removed.

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