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问充分尊重WPF MVVM，在每个节点中创建具有不同子对象的TreeView
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Stack Overflow用户

提问于 2015-09-04 10:49:46

回答 3查看 988关注 0票数 0

我希望在充分尊重Wpf的情况下创建treeView：

根//级别0 B1- Child1 // 1级 B1-1-儿童1-1/2级 B1-2-儿童1-2 B1-3- . B2- Child2 // Level1 B2-1儿童2-1/2级 B2-2儿童2-2 B2-3 .

如您所见，我有3级的TreeView。

级别0:根(总是修正)

第1级:两个孩子(总是固定的)

第2级:动态子级，它们是从两个不同的类创建的

所以，，我的问题是如何在级别2中为级别1中的每个节点创建不同的子级。

我使用了下面的代码，但在1级的父母之下，我总是有相同的孩子。

我已经看过这个网站和网站上提出的许多解决方案.但就是想不出怎么做.

我的尝试：

  public class MyViewModel 
{
    //private ReadOnlyCollection<AttributesMapDocViewModel> _attributeMapDoc;

    public object _document;

    #region Methodes




    private List<Level0ViewModel> _myDoc;

    public List<Level0ViewModel> MyDoc
    {
        get { return _myDoc; }
        set
        {
            _myDoc = value;
        }
    }

    #endregion

    #region Constructeur

    public MyViewModel()
    {


        MyDoc = new List<Level0ViewModel>()
        {
            new Level0ViewModel("Root",_document), //_document conatins data from xml file (code not shown)
        };
    }


    #endregion

}

public class Level0ViewModel : ViewModelBase
{
    private List<Level1ViewModel> _childLevel1;

    public Level0ViewModel(string name, object myObj)
    {
        ChildLeve0Name = name;
        ChildLevel1 = new List<Level1ViewModel>()
        {
            new Level1ViewModel("Child1",myObj),
            new Level1ViewModel("Child2",myObj)
        };
    }

    public List<Level1ViewModel> ChildLevel1
    {
        get
        {
            return _childLevel1;
        }
        set
        {
            SetProperty(ref _childLevel1, value, () => ChildLevel1);

        }
    }

    public string ChildLeve0Name { get; set; }
}

public class Level1ViewModel : ViewModelBase
{
    private ObservableCollection<Level2SecondTypeViewModel> _childLevel2SecondType;
    public ObservableCollection<Level2SecondTypeViewModel> ChildLevel2SecondType
    {
        get { return _childLevel2SecondType; }
        set
        {
            if (_childLevel2SecondType != value)
            {
                SetProperty(ref _childLevel2SecondType, value, () => ChildLevel2SecondType);

            }
        }
    }


    private ObservableCollection<Level2FirstTypeViewModel> _childLevel2FirstType;
    public ObservableCollection<Level2FirstTypeViewModel> ChildLevel2FirstType
    {
        get { return _childLevel2FirstType; }
        set
        {
            if (_childLevel2FirstType != value)
            {
                SetProperty(ref _childLevel2FirstType, value, () => ChildLevel2FirstType);

            }
        }
    }

    public Level1ViewModel(string name, object mapAtt)
    {
        ChildLevel1Name = name;

        ChildLevel2FirstType = new ObservableCollection<Level2FirstTypeViewModel>();
        foreach (FirstType myFirstType in mapAtt.FirstTypes)
        {
            ChildLevel2FirstType.Add(new Level2FirstTypeViewModel(myFirstType));
        }

        ChildLevel2SecondType = new ObservableCollection<Level2SecondTypeViewModel>();
        foreach (SecondType mySecondType in mapAtt.SecondTypes)
        {
            ChildLevel2SecondType.Add(new Level2SecondTypeViewModel(mySecondType));
        }

    }

    public string ChildLevel1Name
    {
        get;
        set;
    }
}

public class Level2FirstTypeViewModel : ViewModelBase
{
    public Level2FirstTypeViewModel(FirstType fType)
    {
        FirstTypeName = fType.name;
    }

    public string FirstTypeName
    {
        get;
        set;
    }
}


public class Level2SecondTypeViewModel
{
    public Level2SecondTypeViewModel(SecondType sType)
    {
        SecondTypeName = sType.name;
    }

    public string SecondTypeName
    {
        get;
        set;
    }

}




 <TreeView ItemsSource="{Binding MyDoc}" >
  <TreeView.Resources>
            <HierarchicalDataTemplate ItemsSource="{Binding MapAttDef}" DataType="{x:Type local:Level0ViewModel}">
                      <Label Content="{Binding ChildLeve0Name}"/>
            </HierarchicalDataTemplate>

            <HierarchicalDataTemplate ItemsSource="{Binding ChildLevel2SecondType}" DataType="{x:Type local:Level1ViewModel}">
                      <Label Content="{Binding ChildLevel1Name}"/>
            </HierarchicalDataTemplate>

            <HierarchicalDataTemplate  DataType="{x:Type local:Level2SecondTypeViewModel}">
                       <Label Content="{Binding FirstTypeName}"/>
            </HierarchicalDataTemplate>

            <HierarchicalDataTemplate  DataType="{x:Type local:Level2FirstTypeViewModel}">
                        <Label Content="{Binding SecondTypeName}"/>
            </HierarchicalDataTemplate>




   </TreeView.Resources>

我的尝试给了我这样的东西(这不是我想要的！)：

根// 0级B1- Child1 //级别1 B1-1-儿童1-1/2级 B1-2-儿童1-2 B1-3- . B2- Child2 // Level1 B2-1儿童1-1/2级 B2-2儿童1-2 B2-3 .

wpf

xaml

mvvm

treeview

回答 3

Stack Overflow用户

发布于 2015-09-04 11:16:07

丢弃这些属性：Level1ViewModel.ChildLevel2FirstType和Level1ViewModel.ChildLevel2SecondType。

你需要一个孩子的收藏。此集合的项类型依赖于继承层次结构，并且应该是最近的共同祖先(最坏的情况是object)，即如下所示：

public Level1ViewModel
{
    public ObservableCollection<object> ChildLevel2
    {
        // ...
    }

    // ...
}

带有这些更改的标记将如下所示：

    <!-- Level 1 -->
    <HierarchicalDataTemplate DataType="{x:Type local:Level1ViewModel}" ItemsSource="{Binding ChildLevel2}">
              <Label Content="{Binding ChildLevel1Name}"/>
    </HierarchicalDataTemplate>

    <!-- Level 1 -->
    <DataTemplate  DataType="{x:Type local:Level2FirstTypeViewModel}">
                <Label Content="{Binding SecondTypeName}"/>
    </DataTemplate>

    <DataTemplate  DataType="{x:Type local:Level2SecondTypeViewModel}">
               <Label Content="{Binding FirstTypeName}"/>
    </DataTemplate>

请注意，HierarchicalDataTemplate必须仅用于分层数据源。对于非层次结构的(如Level2FirstTypeViewModel和Level2SecondTypeViewModel)，使用常规的DataTemplate。

票数 0

Stack Overflow用户

发布于 2015-09-04 13:06:04

public class BaseTreeViewItem<TSource, TParent> : ViewModelBase
{

    // add static field to hold selected Item
    public static BaseTreeViewItem<TSource, TParent> SelectedChild { get; set; }

    private bool _isSelected;
    public bool IsSelected
    {
        get { return _isSelected; }
        set
        {
            if (_isSelected == value) return;

            if (SelectedChild != null)
            {
                SelectedChild.IsSelected = false;
                SelectedChild = null;
            }

            _isSelected = value;

            if (_isSelected)
                SelectedChild = this;

            // NotifyPropertyChanged
        }
    }

    public TParent Parent
    {
        get;
        private set;
    }

    public BaseTreeViewItem(string name, TSource myObj, TParent parent)
    {
        ChildName = name;
        DataSource = myObj;
        Parent = parent;
    }


    public string ChildName { get; set; }
    public TSource DataSource { get; set; }

    public override string ToString()
    {
        return ChildName;
    }
}

// Node

public class MyTreeViewItem<TChild, TSource, TParent> : BaseTreeViewItem<TSource, TParent>, IDeleteItem
    where TParent : IDeleteItem
    where TChild : class
{


    public ObservableCollection<TChild> Children { get; set; }

    public MyTreeViewItem(string name, TSource myObj, TParent parent)
        :base(name,myObj, parent)
    {
        Children = new ObservableCollection<TChild>();
    }

    protected virtual void InitChild()
    {

    }

    public void DeleteItem(object myTreeViewItem)
    {
        Children.Remove(myTreeViewItem as TChild);
    }

    public static void DeleteSelectedItem()
    {
        if (SelectedChild != null && SelectedChild.Parent != null)
        {
            SelectedChild.Parent.DeleteItem(SelectedChild);
        }
    }


}

public class Level0ViewModel : MyTreeViewItem<Level1ViewModel, XmlDocument, IDeleteItem>
{
    protected override sealed void InitChild()
    {
        base.InitChild();
        Children.Add(new Level1ViewModel("Child1", new Level1Src(), this));
        Children.Add(new Level1ViewModel("Child2", new Level1Src(), this));
    }

    public Level0ViewModel(string name, XmlDocument myObj) :
        base(name, myObj,null)
    {
        InitChild();
    }
}

public class Level1ViewModel : MyTreeViewItem<Level2TypeViewModel, Level1Src, Level0ViewModel>
{
    public Level1ViewModel(string name, Level1Src myObj, Level0ViewModel parent)
        : base(name, myObj, parent)
    {
        InitChild();
    }

    protected override sealed void InitChild()
    {
        base.InitChild();
        foreach (FirstType myFirstType in DataSource.FirstTypes)
        {
            Children.Add(new Level2TypeViewModel(myFirstType, this));
        }

        foreach (SecondType mySecondType in DataSource.SecondTypes)
        {
            Children.Add(new Level2TypeViewModel(mySecondType, this));
        }
    }

    // Use linq if tou want child by type
    public IEnumerable<Level2TypeViewModel> ChildType1 
    {
        get
        {
            return Children.Where(item => item.DataSource is FirstType);
        }
    }

    public IEnumerable<Level2TypeViewModel> ChildType2
    {
        get
        {
            return Children.Where(item => item.DataSource is SecondType);
        }
    }
}

public class LevelType
{
    public string Name;
}

public class FirstType : LevelType
{
}

public class SecondType : LevelType
{
}

public class Level2TypeViewModel : BaseTreeViewItem<LevelType, Level1ViewModel>
{
    public Level2TypeViewModel(LevelType sType, Level1ViewModel parent)
        : base(sType.Name, sType, parent)
    {
    }
}

我的数据源是

public Level0ViewModel TreeModel
    {
        get
        {
            return new Level0ViewModel("Root", new XmlDocument());
        }
    }

用于TreeView DataTemplate

<TreeView DataContext="{Binding ElementName=UI, Path=TreeModel}">
        <TreeView.Items>
            <TreeViewItem Header="{Binding ChildName}" ItemsSource="{Binding Path=Children}" >
                <TreeViewItem.ItemTemplate>
                    <HierarchicalDataTemplate ItemsSource="{Binding Children}">
                        <Label Content="{Binding ChildName}"></Label>
                    </HierarchicalDataTemplate>
                </TreeViewItem.ItemTemplate>
            </TreeViewItem>
        </TreeView.Items>

    </TreeView>

第一个treeviewItem是显示根节点。如果不想使用它，可以将数据源更改为

public MyTreeViewItem<Level0ViewModel,object> TreeModel
        {
            get
            {
                MyTreeViewItem<Level0ViewModel,object> src = new MyTreeViewItem<Level0ViewModel, object>("Root", null);
                src.Children.Add(new Level0ViewModel("toto", new XmlDocument()));
                return src;
            }
        }

和DataTemplate到

<TreeView DataContext="{Binding ElementName=UI, Path=TreeModel}" ItemsSource="{Binding Children}">
            <TreeViewItem.ItemTemplate>
                        <HierarchicalDataTemplate ItemsSource="{Binding Children}">
                            <Label Content="{Binding ChildName}"></Label>
                        </HierarchicalDataTemplate>
                    </TreeViewItem.ItemTemplate>
 </TreeView>

采样方式

public class TreeViewItemViewModel : ViewModelBase
{

    // add static field to hold selected Item
    public static TreeViewItemViewModel SelectedChild { get; set; }
    public TreeViewItemViewModel Parent{ get; private set;}
    public string ChildName { get; set; }
    public object DataSource { get; set; }
    private readonly ObservableCollection<TreeViewItemViewModel> _children;

    public ObservableCollection<TreeViewItemViewModel> Children
    {
        get
        {
            return _children;
        }

    }


    private bool _isSelected;
    public bool IsSelected
    {
        get { return _isSelected; }
        set
        {
            if (_isSelected == value) return;

            if (SelectedChild != null)
            {
                SelectedChild.IsSelected = false;
                SelectedChild = null;
            }

            _isSelected = value;

            if (_isSelected)
                SelectedChild = this;

            // NotifyPropertyChanged
        }
    }


    public TreeViewItemViewModel(string name, object myObj, TreeViewItemViewModel parent)
    {
        ChildName = name;
        DataSource = myObj;
        Parent = parent;
        _children = new ObservableCollection<TreeViewItemViewModel>();
    }

    public override string ToString()
    {
        return ChildName;
    }


    protected virtual void InitChild()
    {

    }

    public void DeleteItem(TreeViewItemViewModel myTreeViewItem)
    {
        Children.Remove(myTreeViewItem);
    }

    public static void DeleteSelectedItem()
    {
        if (SelectedChild != null && SelectedChild.Parent != null)
        {
            SelectedChild.Parent.DeleteItem(SelectedChild);
        }
    }
}

票数 0

Stack Overflow用户

发布于 2015-09-07 12:58:35

如果视图中有一个选定的项，则可以使用此方法。

公共类TreeViewItemViewModel : ViewModelBase {

    // add static field to hold selected Item
    public static TreeViewItemViewModel SelectedChild { get; set; }
    public TreeViewItemViewModel Parent{ get; private set;}
    public string ChildName { get; set; }
    public object DataSource { get; set; }
    private readonly ObservableCollection<TreeViewItemViewModel> _children;

    public ObservableCollection<TreeViewItemViewModel> Children
    {
        get
        {
            return _children;
        }

    }


    private bool _isSelected;
    public bool IsSelected
    {
        get { return _isSelected; }
        set
        {
            if (_isSelected == value) return;

            if (SelectedChild != null)
            {
                SelectedChild.IsSelected = false;
                SelectedChild = null;
            }

            _isSelected = value;

            if (_isSelected)
                SelectedChild = this;

            // NotifyPropertyChanged
        }
    }


    public TreeViewItemViewModel(string name, object myObj, TreeViewItemViewModel parent)
    {
        ChildName = name;
        DataSource = myObj;
        Parent = parent;
        _children = new ObservableCollection<TreeViewItemViewModel>();
    }

    public override string ToString()
    {
        return ChildName;
    }


    protected virtual void InitChild()
    {

    }

    public void DeleteItem(TreeViewItemViewModel myTreeViewItem)
    {
        Children.Remove(myTreeViewItem);
    }

    public static void DeleteSelectedItem()
    {
        if (SelectedChild != null && SelectedChild.Parent != null)
        {
            SelectedChild.Parent.DeleteItem(SelectedChild);
        }
    }
}

票数 0

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/32396247

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