IEditableCollectionView.CancelNew Método

Definição

Namespace:

System.ComponentModel

Assembly:

WindowsBase.dll

Termina a transação de adição e descarta o novo item pendente.

public:
 void CancelNew();

public void CancelNew ();

abstract member CancelNew : unit -> unit

Public Sub CancelNew ()

Exemplos

O exemplo a seguir exibe um formulário que solicita que o usuário adicione um novo item. Se o usuário enviar o formulário, o exemplo chamará CommitNew para adicionar o item à coleção. Se o usuário cancelar o formulário, o exemplo chamará CancelNew para descartar o item. Para obter todo o exemplo, consulte Alterando uma coleção usando o exemplo IEditableCollectionView.

IEditableCollectionView editableCollectionView = 
    itemsControl.Items as IEditableCollectionView; 

if (!editableCollectionView.CanAddNew)
{
    MessageBox.Show("You cannot add items to the list.");
    return;
}

// Create a window that prompts the user to enter a new
// item to sell.
ChangeItemWindow win = new ChangeItemWindow();

//Create a new item to be added to the collection.
win.DataContext = editableCollectionView.AddNew();

// If the user submits the new item, commit the new
// object to the collection.  If the user cancels 
// adding the new item, discard the new item.
if ((bool)win.ShowDialog())
{
    editableCollectionView.CommitNew();
}
else
{
    editableCollectionView.CancelNew();
}

Dim editableCollectionView As IEditableCollectionView = TryCast(itemsControl.Items, IEditableCollectionView)

If Not editableCollectionView.CanAddNew Then
    MessageBox.Show("You cannot add items to the list.")
    Return
End If

' Create a window that prompts the user to enter a new
' item to sell.
Dim win As New ChangeItemWindow()

'Create a new item to be added to the collection.
win.DataContext = editableCollectionView.AddNew()

' If the user submits the new item, commit the new
' object to the collection.  If the user cancels 
' adding the new item, discard the new item.
If CBool(win.ShowDialog()) Then
    editableCollectionView.CommitNew()
Else
    editableCollectionView.CancelNew()
End If