如何:在单击标题时对 GridView 列进行排序

此示例演示如何创建一个 ListView 控件,该控件可实现 GridView 视图模式,并在用户单击列标题时对数据内容进行排序。

示例

下面的示例定义了一个包含三个列的 GridView,这些列绑定到 DateTime 结构的 YearMonthDay 属性。

<GridView>
  <GridViewColumn DisplayMemberBinding="{Binding Path=Year}"
                  Header="Year"
                  Width="100"/>
  <GridViewColumn DisplayMemberBinding="{Binding Path=Month}"
                  Header="Month"
                  Width="100"/>
  <GridViewColumn DisplayMemberBinding="{Binding Path=Day}"
                  Header="Day"
                  Width="100"/>
</GridView>

下面的示例演示定义为 DateTime 对象的 ArrayList 的数据项。 ArrayList 被定义为 ListView 控件的 ItemsSource

<ListView.ItemsSource>
  <s:ArrayList>
    <p:DateTime>1993/1/1 12:22:02</p:DateTime>
    <p:DateTime>1993/1/2 13:2:01</p:DateTime>
    <p:DateTime>1997/1/3 2:1:6</p:DateTime>
    <p:DateTime>1997/1/4 13:6:55</p:DateTime>
    <p:DateTime>1999/2/1 12:22:02</p:DateTime>
    <p:DateTime>1998/2/2 13:2:01</p:DateTime>
    <p:DateTime>2000/2/3 2:1:6</p:DateTime>
    <p:DateTime>2002/2/4 13:6:55</p:DateTime>
    <p:DateTime>2001/3/1 12:22:02</p:DateTime>
    <p:DateTime>2006/3/2 13:2:01</p:DateTime>
    <p:DateTime>2004/3/3 2:1:6</p:DateTime>
    <p:DateTime>2004/3/4 13:6:55</p:DateTime>
  </s:ArrayList>
</ListView.ItemsSource>

XAML 标记中的 sp 标识符引用在 XAML 页面元数据中定义的命名空间映射。 下面的示例显示了元数据定义。

<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Class="ListViewSort.Window1"
    xmlns:s="clr-namespace:System.Collections;assembly=mscorlib"
    xmlns:p="clr-namespace:System;assembly=mscorlib">

为了根据列的内容对数据进行排序,该示例定义了一个事件处理程序,用于处理当按下列标题按钮时发生的 Click 事件。 以下示例显示如何为 GridViewColumnHeader 控件指定事件处理程序。

<ListView x:Name='lv' Height="150" HorizontalAlignment="Center"
  VerticalAlignment="Center"
  GridViewColumnHeader.Click="GridViewColumnHeaderClickedHandler"
 >

该示例定义了事件处理程序,以便每次按下列标题按钮时,排序方向会在升序和降序之间发生变化。 以下示例显示了 事件处理程序。

public partial class Window1 : Window
{
    public Window1()
    {
        InitializeComponent();
    }

    GridViewColumnHeader _lastHeaderClicked = null;
    ListSortDirection _lastDirection = ListSortDirection.Ascending;

    void GridViewColumnHeaderClickedHandler(object sender,
                                            RoutedEventArgs e)
    {
        var headerClicked = e.OriginalSource as GridViewColumnHeader;
        ListSortDirection direction;

        if (headerClicked != null)
        {
            if (headerClicked.Role != GridViewColumnHeaderRole.Padding)
            {
                if (headerClicked != _lastHeaderClicked)
                {
                    direction = ListSortDirection.Ascending;
                }
                else
                {
                    if (_lastDirection == ListSortDirection.Ascending)
                    {
                        direction = ListSortDirection.Descending;
                    }
                    else
                    {
                        direction = ListSortDirection.Ascending;
                    }
                }

                var columnBinding = headerClicked.Column.DisplayMemberBinding as Binding;
                var sortBy = columnBinding?.Path.Path ?? headerClicked.Column.Header as string;

                Sort(sortBy, direction);

                if (direction == ListSortDirection.Ascending)
                {
                    headerClicked.Column.HeaderTemplate =
                      Resources["HeaderTemplateArrowUp"] as DataTemplate;
                }
                else
                {
                    headerClicked.Column.HeaderTemplate =
                      Resources["HeaderTemplateArrowDown"] as DataTemplate;
                }

                // Remove arrow from previously sorted header
                if (_lastHeaderClicked != null && _lastHeaderClicked != headerClicked)
                {
                    _lastHeaderClicked.Column.HeaderTemplate = null;
                }

                _lastHeaderClicked = headerClicked;
                _lastDirection = direction;
            }
        }
    }
}
Partial Public Class Window1
    Inherits Window
    Public Sub New()
        InitializeComponent()
    End Sub

    Private _lastHeaderClicked As GridViewColumnHeader = Nothing
    Private _lastDirection As ListSortDirection = ListSortDirection.Ascending

    Private Sub GridViewColumnHeaderClickedHandler(ByVal sender As Object, ByVal e As RoutedEventArgs)
        Dim headerClicked = TryCast(e.OriginalSource, GridViewColumnHeader)
        Dim direction As ListSortDirection

        If headerClicked IsNot Nothing Then
            If headerClicked.Role <> GridViewColumnHeaderRole.Padding Then
                If headerClicked IsNot _lastHeaderClicked Then
                    direction = ListSortDirection.Ascending
                Else
                    If _lastDirection = ListSortDirection.Ascending Then
                        direction = ListSortDirection.Descending
                    Else
                        direction = ListSortDirection.Ascending
                    End If
                End If

                Dim columnBinding = TryCast(headerClicked.Column.DisplayMemberBinding, Binding)
                Dim sortBy = If(columnBinding?.Path.Path, TryCast(headerClicked.Column.Header, String))

                Sort(sortBy, direction)

                If direction = ListSortDirection.Ascending Then
                    headerClicked.Column.HeaderTemplate = TryCast(Resources("HeaderTemplateArrowUp"), DataTemplate)
                Else
                    headerClicked.Column.HeaderTemplate = TryCast(Resources("HeaderTemplateArrowDown"), DataTemplate)
                End If

                ' Remove arrow from previously sorted header
                If _lastHeaderClicked IsNot Nothing AndAlso _lastHeaderClicked IsNot headerClicked Then
                    _lastHeaderClicked.Column.HeaderTemplate = Nothing
                End If

                _lastHeaderClicked = headerClicked
                _lastDirection = direction
            End If
        End If
    End Sub
End Class

下面的示例演示由事件处理程序调用以供对数据进行排序的排序算法。 通过创建新的 SortDescription 结构执行排序。

private void Sort(string sortBy, ListSortDirection direction)
{
    ICollectionView dataView =
      CollectionViewSource.GetDefaultView(lv.ItemsSource);

    dataView.SortDescriptions.Clear();
    SortDescription sd = new SortDescription(sortBy, direction);
    dataView.SortDescriptions.Add(sd);
    dataView.Refresh();
}
Private Sub Sort(ByVal sortBy As String, ByVal direction As ListSortDirection)
    Dim dataView As ICollectionView = CollectionViewSource.GetDefaultView(lv.ItemsSource)

    dataView.SortDescriptions.Clear()
    Dim sd As New SortDescription(sortBy, direction)
    dataView.SortDescriptions.Add(sd)
    dataView.Refresh()
End Sub

另请参阅