取消或保存对DataGrid中的自定义对象所做的更改

Question

我有一个DataGrid，它的ItemsSource设置为自定义对象的ObservableCollection，它从窗口传递到包含DataGrid的用户控件，尽管效果很好，并且更改在两个方向上都注册了，但我想拥有这种能力如果我单击取消按钮，则取消在UserControl中所做的任何更改。

有什么方法可以将我在DataGrid中所做的任何更改推迟到父窗口中的ItemSource？ 或者相反，如果我选择的话，可以取消更改。 任何帮助将不胜感激，这是我当前的代码；

   public UserControl1(ObservableCollection<ContourControl.RectangleContour> list1)
    {
        InitializeComponent();
        itemCollectionViewSource = (CollectionViewSource)(FindResource("ItemCollectionViewSource"));

        itemCollectionViewSource.Source = list1;

        //here i create some columns and bind the data

        DataGridViewer.ItemsSource = list1;
        DataGridViewer.AutoGenerateColumns = false;

    }

    private void Cancel(object sender, RoutedEventArgs e)
    {
        //if i click this i would like any changes to list1 to be reverted or ignored

        Window parentWindow = Window.GetWindow((DependencyObject)sender);
        if (parentWindow != null)
        {
            parentWindow.Close();
        }
    }

    private void OK(object sender, RoutedEventArgs e)
    {
        //if i click this i would like the changes to carry on to my list, as it currently does instantly

        Window parentWindow = Window.GetWindow((DependencyObject)sender);
        if (parentWindow != null)
        {
            parentWindow.Close();
        }
    }

这是启动我的用户控件并传递原始列表的代码，我将数据存储在其中。

                Window window = new Window
            {
                Height = 200,
                Width = 765,
                Content = new UserControl1(list1: rectContourList),
            };
            window.ShowDialog();

Answer 1

您可以将UpdateSourceTrigger=Explicit设置为文本框。

 <TextBox Name="tb1" Text="{Binding tbval, UpdateSourceTrigger=Explicit}"/>

然后在“确定”按钮上单击更新源

 private void OK_Button_Click(object sender, RoutedEventArgs e)
        {
            BindingExpression binding = tb1.GetBindingExpression(TextBox.TextProperty);
            binding.UpdateSource();
        }

如果要在文本框中显示先前的值，则在“取消”上将先前的属性设置回去，否则可以将其保留为空。

private void Cancel_Button_Click_1(object sender, RoutedEventArgs e)
        {
            //tbval is the property binded to Textbox
            tbval = tbval;
        }

https://msdn.microsoft.com/en-us/library/system.windows.data.binding.updatesourcetrigger.aspx