IEditableCollectionView.CancelNew 方法

定义

命名空间:

System.ComponentModel

程序集:

WindowsBase.dll

结束添加事务并放弃挂起的新项。

public:
 void CancelNew();

public void CancelNew ();

abstract member CancelNew : unit -> unit

Public Sub CancelNew ()

示例

以下示例显示一个窗体，该窗体提示用户添加新项。 如果用户提交表单，则示例调用 CommitNew 以将项添加到集合中。 如果用户取消窗体，则示例调用 CancelNew 以放弃该项。 有关整个示例，请参阅 使用 IEditableCollectionView 示例更改集合。

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