ViewModel 有 2 个字段。 Name
, Childs
我需要这样1
。当点击根元素时,做2个操作first
。扩展自己second
。选择第一个 child 。如果子元素有子元素,请重复 1
。
否则什么都不做
只有最后一个 child (叶子)可选
最佳答案
更新
想出了一个更好的方法来做到这一点。这也将解释 ObservableCollection 的变化。
Xaml 可以看起来像这样
<Window.Resources>
<HierarchicalDataTemplate x:Key="Level1"
ItemsSource="{Binding Path=Childs}">
<TextBlock Text="{Binding Path=Name}"/>
</HierarchicalDataTemplate>
</Window.Resources>
<TreeView ItemsSource="{Binding}"
...>
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="IsSelected" Value="{Binding Path=IsSelected, Mode=TwoWay}" />
<Setter Property="IsExpanded" Value="{Binding Path=IsExpanded, Mode=TwoWay}" />
</Style>
</TreeView.ItemContainerStyle>
</TreeView>
然后我们在 Model/ViewModel 中处理 IsSelected 属性。
public class MyViewModel : INotifyPropertyChanged
{
private static MyViewModel s_lastSelectedTestItem = null;
public MyViewModel(string name)
{
Name = name;
m_isSelected = false;
Childs = new ObservableCollection<MyViewModel>();
Childs.CollectionChanged += new NotifyCollectionChangedEventHandler(TestItems_CollectionChanged);
}
void TestItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (IsSelected == true && Childs.Count > 0)
{
Childs[0].IsSelected = true;
IsExpanded = true;
}
}
public string Name
{
get;
set;
}
public ObservableCollection<MyViewModel> Childs
{
get;
set;
}
private bool m_isSelected;
public bool IsSelected
{
get
{
return m_isSelected;
}
set
{
m_isSelected = value;
if (m_isSelected == true)
{
if (s_lastSelectedTestItem != null)
{
s_lastSelectedTestItem.IsSelected = false;
}
s_lastSelectedTestItem = this;
if (Childs.Count > 0)
{
IsExpanded = true;
Childs[0].IsSelected = true;
m_isSelected = false;
}
}
OnPropertyChanged("IsSelected");
}
}
private bool m_isExpaned;
public bool IsExpanded
{
get
{
return m_isExpaned;
}
set
{
m_isExpaned = value;
OnPropertyChanged("IsExpanded");
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
关于wpf - 我需要这样的 Wpf 树 View ,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/3923640/