绑定当前对象例子——Tag="{Binding}"

<TreeView Margin="10,5,0,0" HorizontalAlignment="Left"  VerticalAlignment="Stretch" Grid.Column="2" Grid.Row="1" Grid.RowSpan="4"  Width="172" x:Name="tv_Orgs" ItemsSource="{Binding OrgTreeNodes}"   ItemContainerStyle="{StaticResource OrgTreeViewItemStyle}" Style="{DynamicResource OrgTreeViewStyle}">
                <TreeView.ItemTemplate>
                    <HierarchicalDataTemplate DataType="{x:Type dataEntity:OrgData}" ItemsSource="{Binding Nodes}"> <!--ItemsSource="{Binding Nodes}"-->
                        <StackPanel Orientation="Horizontal" Margin="0,2,0,2">
                            <!--<StackPanel Orientation="Horizontal">-->
                                <CheckBox x:Name="treeViewItemCheckBox" Tag="{Binding}" IsChecked="{Binding IsChecked, Mode= TwoWay,UpdateSourceTrigger=PropertyChanged}" VerticalAlignment="Center" Style="{StaticResource CheckBoxStyle1}" Click="treeViewItemCheckBox_Click" />
                                <TextBlock Text="{Binding OrgName,Mode=TwoWay}" ToolTip="{Binding OrgName,Mode=TwoWay}" Margin="2,0,0,0"/>
                            <!--</StackPanel>-->
                        </StackPanel>
                    </HierarchicalDataTemplate>
                </TreeView.ItemTemplate>
            </TreeView>