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【WPF】树形结构TreeView的用法（MVVM）

 

TreeView控件的用法还是有蛮多坑点的，最好记录一下。

参考项目：

• https://www.codeproject.com/Articles/26288/Simplifying-the-WPF-TreeView-by-Using-the-ViewMode

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静态的树形结构

如果树形结构的所有子节点都已经确定且不会改动，可以直接在控制层用C#代码来生成这个TreeView。

            var rootItem = new OutlineTreeData
            {
                outlineTypeName = "David Weatherbeam",
                Children=
                {
                    new OutlineTreeData
                    {
                        outlineTypeName="Alberto Weatherbeam",
                        Children=
                        {
                            new OutlineTreeData
                            {
                                outlineTypeName="Zena Hairmonger",
                                Children=
                                {
                                    new OutlineTreeData
                                    {
                                        outlineTypeName="Sarah Applifunk",
                                    }
                                }
                            },new OutlineTreeData
                            {
                                outlineTypeName="Jenny van Machoqueen",
                                Children=
                                {
                                    new OutlineTreeData
                                    {
                                        outlineTypeName="Nick van Machoqueen",
                                    },
                                    new OutlineTreeData
                                    {
                                        outlineTypeName="Matilda Porcupinicus",
                                    },
                                    new OutlineTreeData
                                    {
                                        outlineTypeName="Bronco van Machoqueen",
                                    }
                                }
                            }
                        }
                    },
                    new OutlineTreeData
                    {
                        outlineTypeName="Komrade Winkleford",
                        Children=
                        {
                            new OutlineTreeData
                            {
                                outlineTypeName="Maurice Winkleford",
                                Children=
                                {
                                    new OutlineTreeData
                                    {
                                        outlineTypeName="Divinity W. Llamafoot",
                                    }
                                }
                            },
                            new OutlineTreeData
                            {
                                outlineTypeName="Komrade Winkleford, Jr.",
                                Children=
                                {
                                    new OutlineTreeData
                                    {
                                        outlineTypeName="Saratoga Z. Crankentoe",
                                    },
                                    new OutlineTreeData
                                    {
                                        outlineTypeName="Excaliber Winkleford",
                                    }
                                }
                            }
                        }
                    }
                }
            };    

运行后能看到树形结构是下面的样子。

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获取TreeViewItem控件

前台页面xaml：

 <!-- 树形结构 -->
 <TreeView x:Name="treeView" VerticalAlignment="Top" HorizontalAlignment="Left" Margin="10,-10,0,0"
           ItemsSource="{Binding ItemTreeDataList}" BorderThickness="0" Width="215" Height="210">
     <TreeView.ItemContainerStyle>
         <Style TargetType="{x:Type TreeViewItem}">
             <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}" />
             <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />
             <Setter Property="FontWeight" Value="Normal" />
             <Style.Triggers>
                 <Trigger Property="IsSelected" Value="True">
                     <Setter Property="FontWeight" Value="Bold" />
                 </Trigger>
             </Style.Triggers>
         </Style>
     </TreeView.ItemContainerStyle>

     <TreeView.ItemTemplate>
         <HierarchicalDataTemplate ItemsSource="{Binding Children}">
             <TextBlock x:Name="treeViewItemTB" Text="{Binding itemName}" Tag="{Binding itemId}"/>
         </HierarchicalDataTemplate>
     </TreeView.ItemTemplate>
 </TreeView>  

尝试过在初始化时获取TreeViewItem，发现都是为Null。

• TreeViewItem item= (TreeViewItem)(myWindow.treeView.ItemContainerGenerator.ContainerFromIndex(0)); // 无法获取，为Null！
• VisualTreeHelper.GetChild(); // 无法获取，为Null！

谷歌一下，看到这篇解答，下面这位跟我遇到的情况一样，用以上方法都无法获取TreeViewItem。