C# 传递一个控件'；s ItemsSource作为依赖项属性的值_C#_Wpf_Xaml

C# 传递一个控件'；s ItemsSource作为依赖项属性的值

c# wpf xaml

C# 传递一个控件'；s ItemsSource作为依赖项属性的值,c#,wpf,xaml,C#,Wpf,Xaml,我有一个自定义ListView控件，它将ModelItems列表作为其ItemsSource： <customControls:ListViewEx Name="DocumentListView" ItemsSource="{Binding ModelItems, Mode=OneWay}"> 我希望将ModelItems作为值传递给此依赖项属性，我已尝试这样做： <GridView.ColumnHe

我有一个自定义ListView控件，它将ModelItems列表作为其ItemsSource：

          <customControls:ListViewEx Name="DocumentListView"
                ItemsSource="{Binding ModelItems, Mode=OneWay}">

我希望将

ModelItems

作为值传递给此依赖项属性，我已尝试这样做：

            <GridView.ColumnHeaderContainerStyle>
              <Style BasedOn="{StaticResource {x:Type GridViewColumnHeader}}" TargetType="{x:Type GridViewColumnHeader}">
                <Setter Property = "misc:GridViewColumnHeaderClick.HeaderClick" 
                        Value="{Binding ModelItems}"/>
              </Style>
            </GridView.ColumnHeaderContainerStyle>

但是，当我单击标题时，似乎什么也没有发生。我不确定这是因为我在XAML中错误地绑定了它，还是因为完全不同的原因

编辑：为缺乏细节道歉，我理解这有点混乱

我的总体目标是通过单击GridViewColumn的标题来运行排序函数。

GridView

是

ListViewEx

的子项。单击标题时，我希望将其绑定到

HeaderClick

属性，并将该值设置为

ListView

的

ItemsSource

（在本例中为

ItemsSource=modelsitems

），以便对其进行排序

单击后，将运行函数

OnHeaderClickChanged

：

        private static void OnHeaderClickChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
    {
        var headerClicked = sender as GridViewColumnHeader;
        headerClicked.MouseUp += (s, me) => HeaderClickedOnMouseUp(s, me, e.NewValue);
    }

这会将函数

headerclickednomouseup

添加到

MouseUp

事件中。此函数是使用

ModelItems

执行排序的函数

我的问题是，当涉及到依赖/附加属性以及如何将其与视图绑定时，我缺乏理解。正如在注释中正确提到的，在调试setter时，在任何时候都不会调用它，我不明白为什么会这样

这是一个使用升序排序的简单排序示例。应在

GridViewColumnHeader

上设置附加属性

Sort.IsEnabled

。排序本身是通过设置列父级

ListView.ItemsSource的默认CollectionView
的SortDescription
来完成的
推荐阅读：




数据模型：
Person.cs
class Person
{
  public Person(string firstName, string lastName)
  {
    this.FirstName = firstName;
    this.LastName = lastName;
  }

  public string FirstName { get; set; }
  public string LastName { get; set; }
}

class ViewModel : INotifyPropertyChanged
{
  public ViewModel()
  {
    this.Persons = new ObservableCollection<Person>()
    {
      new Person("Derek", "Zoolander"),
      new Person("Tony", "Montana"),
      new Person("The", "Dude")
    };
  }

  public ObservableCollection<Person> Persons { get; set; }
}   

class Sort : DependencyObject
{
  #region IsEnabled attached property

  public static readonly DependencyProperty IsEnabledProperty = DependencyProperty.RegisterAttached(
    "IsEnabled", typeof(bool), typeof(Sort), new PropertyMetadata(false, Sort.OnIsEnabled));

  public static void SetIsEnabled([NotNull] DependencyObject attachingElement, bool value) => attachingElement.SetValue(Sort.IsEnabledProperty, value);

  public static bool GetIsEnabled([NotNull] DependencyObject attachingElement) => (bool) attachingElement.GetValue(Sort.IsEnabledProperty);

  #endregion

  private static void OnIsEnabled(DependencyObject attachingElement, DependencyPropertyChangedEventArgs e)
  {
    bool isSortingEnabled = (bool) e.NewValue;
    if (isSortingEnabled == (bool) e.OldValue)
    {
      return;
    }

    if (attachingElement is GridViewColumnHeader columnHeader)
    {
      if (isSortingEnabled)
      {
        columnHeader.Click += Sort.SortByColumn;
      }
      else
      {
        columnHeader.Click -= Sort.SortByColumn;
      }  
    }
  }

  private static void SortByColumn(object sender, RoutedEventArgs e)
  {
    var columnHeader = sender as GridViewColumnHeader;
    PropertyPath columnSourceProperty = (columnHeader.Column.DisplayMemberBinding as Binding).Path;

    // Use an extension method to find the parent ListView 
    // by traversing the visual tree
    if (columnHeader.TryFindVisualParentElement(out ListView parentListView))
    {
      var collectionView = (CollectionView)CollectionViewSource.GetDefaultView(parentListView.ItemsSource);
      collectionView.SortDescriptions.Clear();

      // Apply sorting
      collectionView.SortDescriptions.Add(new SortDescription(columnSourceProperty.Path, ListSortDirection.Ascending));
    }
  }
}

public static class Extensions
{
  /// <summary>
  /// Traverses the visual tree towards the root until an element with a matching element name is found.
  /// </summary>
  /// <typeparam name="TParent">The type the visual parent must match.</typeparam>
  /// <param name="child"></param>
  /// <param name="resultElement"></param>
  /// <returns><c>true</c> when the parent visual was found otherwise <c>false</c></returns>
  public static bool TryFindVisualParentElement<TParent>(this DependencyObject child, out TParent resultElement)
    where TParent : DependencyObject
  {
    resultElement = null;

    DependencyObject parentElement = VisualTreeHelper.GetParent(child);

    if (parentElement is TParent parent)
    {
      resultElement = parent;
      return true;
    }

    return parentElement?.TryFindVisualParentElement(out resultElement) ?? false;
  }
}

ViewModel.cs
class Person
{
  public Person(string firstName, string lastName)
  {
    this.FirstName = firstName;
    this.LastName = lastName;
  }

  public string FirstName { get; set; }
  public string LastName { get; set; }
}

class ViewModel : INotifyPropertyChanged
{
  public ViewModel()
  {
    this.Persons = new ObservableCollection<Person>()
    {
      new Person("Derek", "Zoolander"),
      new Person("Tony", "Montana"),
      new Person("The", "Dude")
    };
  }

  public ObservableCollection<Person> Persons { get; set; }
}   

class Sort : DependencyObject
{
  #region IsEnabled attached property

  public static readonly DependencyProperty IsEnabledProperty = DependencyProperty.RegisterAttached(
    "IsEnabled", typeof(bool), typeof(Sort), new PropertyMetadata(false, Sort.OnIsEnabled));

  public static void SetIsEnabled([NotNull] DependencyObject attachingElement, bool value) => attachingElement.SetValue(Sort.IsEnabledProperty, value);

  public static bool GetIsEnabled([NotNull] DependencyObject attachingElement) => (bool) attachingElement.GetValue(Sort.IsEnabledProperty);

  #endregion

  private static void OnIsEnabled(DependencyObject attachingElement, DependencyPropertyChangedEventArgs e)
  {
    bool isSortingEnabled = (bool) e.NewValue;
    if (isSortingEnabled == (bool) e.OldValue)
    {
      return;
    }

    if (attachingElement is GridViewColumnHeader columnHeader)
    {
      if (isSortingEnabled)
      {
        columnHeader.Click += Sort.SortByColumn;
      }
      else
      {
        columnHeader.Click -= Sort.SortByColumn;
      }  
    }
  }

  private static void SortByColumn(object sender, RoutedEventArgs e)
  {
    var columnHeader = sender as GridViewColumnHeader;
    PropertyPath columnSourceProperty = (columnHeader.Column.DisplayMemberBinding as Binding).Path;

    // Use an extension method to find the parent ListView 
    // by traversing the visual tree
    if (columnHeader.TryFindVisualParentElement(out ListView parentListView))
    {
      var collectionView = (CollectionView)CollectionViewSource.GetDefaultView(parentListView.ItemsSource);
      collectionView.SortDescriptions.Clear();

      // Apply sorting
      collectionView.SortDescriptions.Add(new SortDescription(columnSourceProperty.Path, ListSortDirection.Ascending));
    }
  }
}

public static class Extensions
{
  /// <summary>
  /// Traverses the visual tree towards the root until an element with a matching element name is found.
  /// </summary>
  /// <typeparam name="TParent">The type the visual parent must match.</typeparam>
  /// <param name="child"></param>
  /// <param name="resultElement"></param>
  /// <returns><c>true</c> when the parent visual was found otherwise <c>false</c></returns>
  public static bool TryFindVisualParentElement<TParent>(this DependencyObject child, out TParent resultElement)
    where TParent : DependencyObject
  {
    resultElement = null;

    DependencyObject parentElement = VisualTreeHelper.GetParent(child);

    if (parentElement is TParent parent)
    {
      resultElement = parent;
      return true;
    }

    return parentElement?.TryFindVisualParentElement(out resultElement) ?? false;
  }
}

用于查找可视父对象的扩展助手方法：
Extensions.cs
class Person
{
  public Person(string firstName, string lastName)
  {
    this.FirstName = firstName;
    this.LastName = lastName;
  }

  public string FirstName { get; set; }
  public string LastName { get; set; }
}

class ViewModel : INotifyPropertyChanged
{
  public ViewModel()
  {
    this.Persons = new ObservableCollection<Person>()
    {
      new Person("Derek", "Zoolander"),
      new Person("Tony", "Montana"),
      new Person("The", "Dude")
    };
  }

  public ObservableCollection<Person> Persons { get; set; }
}   

class Sort : DependencyObject
{
  #region IsEnabled attached property

  public static readonly DependencyProperty IsEnabledProperty = DependencyProperty.RegisterAttached(
    "IsEnabled", typeof(bool), typeof(Sort), new PropertyMetadata(false, Sort.OnIsEnabled));

  public static void SetIsEnabled([NotNull] DependencyObject attachingElement, bool value) => attachingElement.SetValue(Sort.IsEnabledProperty, value);

  public static bool GetIsEnabled([NotNull] DependencyObject attachingElement) => (bool) attachingElement.GetValue(Sort.IsEnabledProperty);

  #endregion

  private static void OnIsEnabled(DependencyObject attachingElement, DependencyPropertyChangedEventArgs e)
  {
    bool isSortingEnabled = (bool) e.NewValue;
    if (isSortingEnabled == (bool) e.OldValue)
    {
      return;
    }

    if (attachingElement is GridViewColumnHeader columnHeader)
    {
      if (isSortingEnabled)
      {
        columnHeader.Click += Sort.SortByColumn;
      }
      else
      {
        columnHeader.Click -= Sort.SortByColumn;
      }  
    }
  }

  private static void SortByColumn(object sender, RoutedEventArgs e)
  {
    var columnHeader = sender as GridViewColumnHeader;
    PropertyPath columnSourceProperty = (columnHeader.Column.DisplayMemberBinding as Binding).Path;

    // Use an extension method to find the parent ListView 
    // by traversing the visual tree
    if (columnHeader.TryFindVisualParentElement(out ListView parentListView))
    {
      var collectionView = (CollectionView)CollectionViewSource.GetDefaultView(parentListView.ItemsSource);
      collectionView.SortDescriptions.Clear();

      // Apply sorting
      collectionView.SortDescriptions.Add(new SortDescription(columnSourceProperty.Path, ListSortDirection.Ascending));
    }
  }
}

public static class Extensions
{
  /// <summary>
  /// Traverses the visual tree towards the root until an element with a matching element name is found.
  /// </summary>
  /// <typeparam name="TParent">The type the visual parent must match.</typeparam>
  /// <param name="child"></param>
  /// <param name="resultElement"></param>
  /// <returns><c>true</c> when the parent visual was found otherwise <c>false</c></returns>
  public static bool TryFindVisualParentElement<TParent>(this DependencyObject child, out TParent resultElement)
    where TParent : DependencyObject
  {
    resultElement = null;

    DependencyObject parentElement = VisualTreeHelper.GetParent(child);

    if (parentElement is TParent parent)
    {
      resultElement = parent;
      return true;
    }

    return parentElement?.TryFindVisualParentElement(out resultElement) ?? false;
  }
}

公共静态类扩展
{
/// 
///向根遍历可视树，直到找到具有匹配元素名称的元素。
/// 
///视觉父级必须匹配的类型。
/// 
/// 
///当发现父视觉对象时为true，否则为false
public static bool TryFindVisualParentElement（此DependencyObject子对象，out tParentResultElement）
其中TParent:DependencyObject
{
resultElement=null；
DependencyObject parentElement=VisualTreeHelper.GetParent（子级）；
if（parentElement是TParent父元素）
{
结果成分=父母；
返回true；
}
返回parentElement？.TryFindVisualParentElement（OutResultElement）？false；
}
}

用法：
main window.xaml
<Window>
  <Window.DataContext>
    <ViewModel />
  </Window.DataContext>

  <ListView ItemsSource="{Binding Persons}">
    <ListView.View>
      <GridView>
        <GridViewColumn DisplayMemberBinding="{Binding FirstName}">
          <GridViewColumnHeader Sort.IsEnabled="True" Content="First Name" />
        </GridViewColumn>
        <GridViewColumn DisplayMemberBinding="{Binding LastName}">
          <GridViewColumnHeader Sort.IsEnabled="True" Content="Last Name" />
        </GridViewColumn>
      </GridView>
    </ListView.View>
  </ListView>
</Window>


GridViewColumnHeaderClick。HeaderClick
在类型GridViewColumnHeader
上不存在，并且不是附加属性。因此，Setter
将永远不会执行。对不起，您能稍微扩展一下吗？这是否意味着我不应该将目标类型指定为GridViewColumnHeader
。我对依赖属性的概念还不太熟悉，所以我不确定它不是附加属性是什么意思。您使用该属性的方式使它看起来像是附加属性，但它不是。它是类型GridViewColumnHeaderClick
上的一个简单依赖属性，没有人知道它的作用。当我读到你的问题时，我最初的想法也是“对不起，你能稍微扩展一下吗？”。我无法提供解决方案，因为我不知道您在做什么。您只提供了随机代码片段，没有上下文和解释。我所能看到的是，您正在为GridView
的GridViewColumnHeader
设置样式。您的setter正在设置一个在GridViewColumnHeader
@monadoboi的上下文中不存在的属性：为什么在单击标题时会设置附加属性？您是否在某处处理单击？@mm8是的，我需要的功能已添加到MouseUp
事件中。我对这个问题补充了一些细节。谢谢