WPF遍历ListView中的项

我有一个 ListView 用一个 CheckBox 作为列之一,绑定到自定义对象的布尔属性。我正在尝试了解如何迭代 列表视图 并选中所有复选框。到目前为止,我有以下几点:

XAML:

<ListView x:Name="MyListView" DockPanel.Dock="Top" Height="275" IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding}">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Enabled">
                <GridViewColumn.CellTemplate>
                    <DataTemplate>
                        <CheckBox IsChecked="{Binding Path=IsChecked}" Click="CheckBox_Click" />
                    </DataTemplate>
                </GridViewColumn.CellTemplate>
            </GridViewColumn>
        </GridView>
    </ListView.View>
</ListView>

VB.NET:

Private Sub SelectAll_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles SelectAll.Click
    Dim currSelected As Integer = MyListView.SelectedIndex
    MyListView.SelectAll()
    For ixItem As Integer = 0 To MyListView.SelectedItems.Count - 1
        coItems(ixItem).IsChecked = True
    Next
    MyListView.SelectedIndex = currSelected
End Sub

我有一种预感,这其实很容易,我只是在某个地方漏了一行。谢谢你的帮助!

更新: 更具体的问题是,按下按钮时可见的复选框不会显示为选中,但不可见的复选框(因为用户需要向下滚动才能看到它们)显示为选中。

更新2: 根据要求,这里是propertychanged代码。我对wpf还比较陌生,我以前对inotifypropertieschanged做得不多。

Public Property blnIsChecked() As Boolean
        Get
            Return _blnIsChecked
        End Get
        Set(ByVal value As Boolean)
            _blnIsChecked = value
        End Set
    End Property

Public Event PropertyChangedHandler(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged