重写TreeView，自定义图标，生成通行的下划线，取消默认获得焦点失去焦点的效果，并支持拖拽节点到外界
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2022-07-01 11:24:34
1、运行效果： 2、前端代码 1
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1、运行效果：
2、前端代码
1 <UserControl x:Class="iPIS.UI.Base.Tree.VideoTreeControl"
2 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
3 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
4 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
5 xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
6 xmlns:local="clr-namespace:iPIS.UI.Base.Tree"
7 mc:Ignorable="d"
8 d:DesignHeight="50" d:DesignWidth="80">
9 <UserControl.Resources>
10 <ResourceDictionary>
11 <ResourceDictionary.MergedDictionaries>
12 <ResourceDictionary Source="/iPIS.UI.Themes.Black;component/Base/Tree/VideoTreeControlImages.xaml"/>
13 </ResourceDictionary.MergedDictionaries>
14 <Style TargetType="TextBlock" x:Key="fontstyle">
15 <Setter Property="Foreground" Value="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=local:VideoTreeControl},Path=VideoTreeControlFontColor}"></Setter>
16 <Setter Property="FontSize" Value="14"></Setter>
17 <Setter Property="VerticalAlignment" Value="Center"></Setter>
18 </Style>
19 </ResourceDictionary>
20 </UserControl.Resources>
21 <Grid>
22 <TreeView x:Name="tree"
23 AllowDrop="True"
24 ItemsSource="{Binding DataList}"
25 Background="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=local:VideoTreeControl},Path=VideoTreeControlBackground}"
26 >
27 <TreeView.ItemTemplate>
28 <HierarchicalDataTemplate ItemsSource="{Binding Children}">
29 <Grid x:Name="grid"
30 Margin="-1 0 0 0"
31 Background="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=local:VideoTreeControl},Path=VideoTreeControlBackground}"
32 >
33 <StackPanel Grid.Column="1"
34 Orientation="Horizontal"
35 Cursor="Hand"
36 Height="40"
37 VerticalAlignment="Center"
38 >
39 <Image x:Name="icon" Width="19" Height="16" VerticalAlignment="Center" Margin="0 0 5 0"></Image>
40 <TextBlock Text="{Binding Text}" Style="{StaticResource fontstyle}"></TextBlock>
41 <StackPanel x:Name="cc"
42 Orientation="Horizontal"
43 Visibility="Collapsed"
44 Margin="0 0 -1 0"
45 Background="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=local:VideoTreeControl},Path=VideoTreeControlBackground}"
46 >
47 <TextBlock Style="{StaticResource fontstyle}">(</TextBlock>
48 <TextBlock Text="{Binding FileCount}" Style="{StaticResource fontstyle}"></TextBlock>
49 <TextBlock Style="{StaticResource fontstyle}">)</TextBlock>
50 </StackPanel>
51 </StackPanel>
52 <!--模拟通行下划线-->
53 <Canvas>
54 <Line X1="0" Y1="39" X2="1000" Y2="39" Stroke="#4a4a4a" Margin="-500 0 0 0" StrokeThickness="1"></Line>
55 </Canvas>
56 </Grid>
57 <HierarchicalDataTemplate.Triggers>
58 <DataTrigger Binding="{Binding Type}" Value="-1">
59 <Setter TargetName="icon" Property="Source" Value="{StaticResource icon_default}"></Setter>
60 </DataTrigger>
61 <DataTrigger Binding="{Binding Type}" Value="0">
62 <Setter TargetName="icon" Property="Source" Value="{StaticResource icon_yuan}"></Setter>
63 </DataTrigger>
64 <DataTrigger Binding="{Binding Type}" Value="1">
65 <Setter TargetName="icon" Property="Source" Value="{StaticResource icon_pian}"></Setter>
66 </DataTrigger>
67 <DataTrigger Binding="{Binding Type}" Value="2">
68 <Setter TargetName="icon" Property="Source" Value="{StaticResource icon_xulie}"></Setter>
69 </DataTrigger>
70 <DataTrigger Binding="{Binding Type}" Value="-1">
71 <Setter TargetName="cc" Property="Visibility" Value="Visible"></Setter>
72 </DataTrigger>
73 </HierarchicalDataTemplate.Triggers>
74 </HierarchicalDataTemplate>
75 </TreeView.ItemTemplate>
76 </TreeView>
77 </Grid>
78 </UserControl>
3、控件的后台代码
1 using iPIS.UI.Base.Model;
2 using iPIS.UI.Base.ViewModel;
3 using System;
4 using System.Collections.Generic;
5 using System.Linq;
6 using System.Text;
7 using System.Threading.Tasks;
8 using System.Windows;
9 using System.Windows.Controls;
10 using System.Windows.Data;
11 using System.Windows.Documents;
12 using System.Windows.Input;
13 using System.Windows.Media;
14 using System.Windows.Media.Imaging;
15 using System.Windows.Navigation;
16 using System.Windows.Shapes;
17
18 namespace iPIS.UI.Base.Tree
19 {
20 /// <summary>
21 /// VideoTreeControl.xaml 的交互逻辑
22 /// </summary>
23 public partial class VideoTreeControl : UserControl
24 {
25 public VideoTreeControl()
26 {
27 InitializeComponent();
28 this.DataContext = new VideoTreeControlViewModel();
29 //默认样式
30 VideoTreeControlBackground = "#36353a";
31 VideoTreeControlFontColor = "#9a9a9a";
32
33 tree.SelectedItemChanged += Tree_SelectedItemChanged;
34 tree.MouseDoubleClick += Tree_MouseDoubleClick;
35 }
36
37 /// <summary>
38 /// 上下文
39 /// </summary>
40 VideoTreeControlViewModel vm
41 {
42 get
43 {
44 return this.DataContext as VideoTreeControlViewModel;
45 }
46 }
47
48 /// <summary>
49 /// 背景颜色
50 /// </summary>
51 public string VideoTreeControlBackground
52 {
53 get { return (string)GetValue(VideoTreeControlBackgroundProperty); }
54 set { SetValue(VideoTreeControlBackgroundProperty, value); }
55 }
56
57 /// <summary>
58 /// 字体颜色
59 /// </summary>
60 public string VideoTreeControlFontColor
61 {
62 get { return (string)GetValue(VideoTreeControlFontColorProperty); }
63 set { SetValue(VideoTreeControlFontColorProperty, value); }
64 }
65
66 #region 附加属性
67
68 public static readonly DependencyProperty VideoTreeControlFontColorProperty =
69 DependencyProperty.Register("VideoTreeControlFontColor", typeof(string), typeof(VideoTreeControl), new PropertyMetadata(""));
70
71 public static readonly DependencyProperty VideoTreeControlBackgroundProperty =
72 DependencyProperty.Register("VideoTreeControlBackground", typeof(string), typeof(VideoTreeControl), new PropertyMetadata(""));
73 #endregion
74
75 #region 公开事件
76 /// <summary>
77 /// 双击节点
78 /// </summary>
79 public event EventHandler<VideoTreeControlItemModel> DoubleClickTreeItem;
80
81 /// <summary>
82 /// 节点选中变更
83 /// </summary>
84 public event EventHandler<VideoTreeControlItemModel> SelectedItemChanged;
85 #endregion
86
87 /// <summary>
88 /// 选中时
89 /// </summary>
90 /// <param name="sender"></param>
91 /// <param name="e"></param>
92 private void Tree_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
93 {
94 var datamodel = e.NewValue as VideoTreeControlItemModel;
95 if (datamodel.Type == VideoTreeControlItemType.Root) return;//过滤root
96 SelectedItemChanged?.Invoke(vm, datamodel);
97 //获取方式 e.Data.GetData(typeof(Base.Model.VideoTreeControlItemModel))
98 DragDrop.DoDragDrop(sender as FrameworkElement, datamodel, DragDropEffects.Copy);
99
100 /*
101 DragDrop.DoDragDrop(sender as FrameworkElement, new ImageTreeControlImageModel()
102 {
103 Text = "我是拖进来的",
104 Type = ImageTreeControlImageType.AlreadyMatting,
105 ImageSource = new BitmapImage(new Uri("D:\\上传资源\\xxx.png", UriKind.Absolute))
106 }, DragDropEffects.Copy);
107 */
108 }
109
110 /// <summary>
111 /// 双击节点
112 /// </summary>
113 /// <param name="sender"></param>
114 /// <param name="e"></param>
115 private void Tree_MouseDoubleClick(object sender, MouseButtonEventArgs e)
116 {
117 var datamodel = tree.SelectedValue as VideoTreeControlItemModel;
118 if (datamodel == null || datamodel.Type == VideoTreeControlItemType.Root) return;//过滤root
119 DoubleClickTreeItem?.Invoke(vm, datamodel);
120 }
121 }
122 }
4、控件的datacontext对象
1 using iPIS.UI.Base.Model;
2 using System;
3 using System.Collections.Generic;
4 using System.Collections.ObjectModel;
5 using System.ComponentModel;
6 using System.Linq;
7 using System.Text;
8 using System.Threading.Tasks;
9 using System.Windows.Input;
10
11 namespace iPIS.UI.Base.ViewModel
12 {
13 public class VideoTreeControlViewModel : INotifyPropertyChanged
14 {
15 public event PropertyChangedEventHandler PropertyChanged;
16
17 private ObservableCollection<VideoTreeControlItemModel> _DataList;
18
19 /// <summary>
20 /// 数据源
21 /// </summary>
22 public ObservableCollection<VideoTreeControlItemModel> DataList
23 {
24 get => _DataList;
25 set
26 {
27 //检查是否有roo，不存在生成默认root
28 if (value.Where(c => c.Type == VideoTreeControlItemType.Root).Count() == 0)
29 {
30 _DataList = new ObservableCollection<VideoTreeControlItemModel>() {
31 new VideoTreeControlItemModel(){
32 Text = "默认",
33 Children = value,
34 Type = VideoTreeControlItemType.Root//标示为root
35 }
36 };
37 }
38 else
39 _DataList = value;
40 PropertyChanged?.Notify(() => this.DataList);
41 }
42 }
43 }
44 }
5、数据实体
1 using System;
2 using System.Collections.Generic;
3 using System.Collections.ObjectModel;
4 using System.Linq;
5 using System.Text;
6 using System.Threading.Tasks;
7
8 namespace iPIS.UI.Base.Model
9 {
10 /// <summary>
11 /// 视频图片树状控件，数据映射实体
12 /// </summary>
13 public class VideoTreeControlItemModel
14 {
15 private string _id = string.Empty;
16 /// <summary>
17 /// 唯一标示符
18 /// </summary>
19 public string Id
20 {
21 get
22 {
23 //如果调用者未显示给入唯一标识符，将默认生成一个唯一标识符
24 if (string.IsNullOrEmpty(_id)) _id = Guid.NewGuid().ToString();
25 return _id;
26 }
27 set
28 {
29 _id = value;
30 }
31 }
32
33 /// <summary>
34 /// 显示值
35 /// </summary>
36 public string Text { get; set; }
37
38 /// <summary>
39 /// 绑定值
40 /// </summary>
41 public object Value { get; set; }
42
43 /// <summary>
44 /// 类型，-1：根；0：原始视频；1：片段
45 /// </summary>
46 public VideoTreeControlItemType Type { get; set; } = VideoTreeControlItemType.Original;
47
48 /// <summary>
49 /// 子集
50 /// </summary>
51 public ObservableCollection<VideoTreeControlItemModel> Children { get; set; } = new ObservableCollection<VideoTreeControlItemModel>();
52
53 /// <summary>
54 /// 文件个数，Type=root时有效
55 /// </summary>
56 public int FileCount
57 {
58 get
59 {
60 if (Type != VideoTreeControlItemType.Root) return 0;
61 List<VideoTreeControlItemModel> outlist = new List<VideoTreeControlItemModel>();
62 GetFiles(this, outlist);
63 return outlist.Count;
64 }
65 }
66
67 /// <summary>
68 /// 获取当前model下所有的文件实体，包含自己
69 /// </summary>
70 /// <param name="model">指定的对象</param>
71 /// <param name="outlist">匹配到的从这里返回</param>
72 private void GetFiles(VideoTreeControlItemModel model, List<VideoTreeControlItemModel> outlist)
73 {
74 if (outlist == null) outlist = new List<VideoTreeControlItemModel>();
75
76 if (model.Type != VideoTreeControlItemType.Root)
77 {
78 outlist.Add(model);
79 }
80 foreach (var item in model.Children)
81 {
82 GetFiles(item, outlist);
83 }
84 }
85 }
86
87 /// <summary>
88 /// 视频树，子项类型
89 /// </summary>
90 public enum VideoTreeControlItemType
91 {
92 /// <summary>
93 /// 根
94 /// </summary>
95 Root = -1,
96 /// <summary>
97 /// 原始视频
98 /// </summary>
99 Original = 0,
100 /// <summary>
101 /// 片段
102 /// </summary>
103 Fragment = 1,
104 /// <summary>
105 /// 序列化
106 /// </summary>
107 Sequence = 2
108 }
109 }
上面是完整效果的全部源码，下面我讲介绍我在封装的时候遇到的问题，并附上解决方案
1、如何自定义图标
答：系统内置一些图标在资源里面，通过属性值绑定不同的图片，因为图标总共就3个所有无需调用者指定，直接内置，通过类型区分匹配即可
下面圈注关键代码
2、如何生成通行的分割线
答：通过Canvas来画线，线条尽可能的长，已达到通行的效果，并且还要距左为负数，已抵消数字控件的子集缩进
附上关键代码
3、自定义树的背景效果加上上，发现一个很囧的问题，获得焦点和失去焦点的节点背景很丑，默认获得焦点是蓝色背景，失去焦点是白色背景，欧码噶
答：肯定是要干掉，必须干掉
附上关键代码
4、由于问题3，又新出一个诡异的问题，就是遮挡不完全，会出现一个1-2像素的竖线，经过调试查看发现是节点内置了border导致的，然后这个又没办法重写掉
答：几经周折，发现利用Margin可以抵消，真是大快人心
附上bug图
这是获得焦点
这是失去焦点
解决的关键代码
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