这是一种方法:
using System;
using System.Collections;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
public static class DataGridSort
{
public static readonly DependencyProperty ComparerProperty = DependencyProperty.RegisterAttached(
"Comparer",
typeof(IComparer),
typeof(DataGridSort),
new PropertyMetadata(
default(IComparer),
OnComparerChanged));
private static readonly DependencyProperty ColumnComparerProperty = DependencyProperty.RegisterAttached(
"ColumnComparer",
typeof(ColumnComparer),
typeof(DataGridSort),
new PropertyMetadata(default(ColumnComparer)));
private static readonly DependencyProperty PreviousComparerProperty = DependencyProperty.RegisterAttached(
"PreviousComparer",
typeof(IComparer),
typeof(DataGridSort),
new PropertyMetadata(default(IComparer)));
public static readonly DependencyProperty UseCustomSortProperty = DependencyProperty.RegisterAttached(
"UseCustomSort",
typeof(bool),
typeof(DataGridSort),
new PropertyMetadata(default(bool), OnUseCustomSortChanged));
public static void SetComparer(DataGridColumn element, IComparer value)
{
element.SetValue(ComparerProperty, value);
}
public static IComparer GetComparer(DataGridColumn element)
{
return (IComparer)element.GetValue(ComparerProperty);
}
public static void SetUseCustomSort(DependencyObject element, bool value)
{
element.SetValue(UseCustomSortProperty, value);
}
public static bool GetUseCustomSort(DependencyObject element)
{
return (bool)element.GetValue(UseCustomSortProperty);
}
private static void OnComparerChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var column = (DataGridColumn)d;
var columnComparer = new ColumnComparer((IComparer)e.NewValue, column);
column.SetValue(ColumnComparerProperty, columnComparer);
}
private static void OnUseCustomSortChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var dataGrid = (DataGrid)d;
if ((bool)e.NewValue)
{
WeakEventManager<DataGrid, DataGridSortingEventArgs>.AddHandler(dataGrid, nameof(dataGrid.Sorting), OnDataGridSorting);
}
else
{
WeakEventManager<DataGrid, DataGridSortingEventArgs>.RemoveHandler(dataGrid, nameof(dataGrid.Sorting), OnDataGridSorting);
}
}
private static void OnDataGridSorting(object sender, DataGridSortingEventArgs e)
{
var column = e.Column;
var columnComparer = (ColumnComparer)column.GetValue(ColumnComparerProperty);
var dataGrid = (DataGrid)sender;
var view = CollectionViewSource.GetDefaultView(dataGrid.ItemsSource) as ListCollectionView;
if (view == null)
{
return;
}
if (columnComparer == null)
{
view.CustomSort = (IComparer)dataGrid.GetValue(PreviousComparerProperty);
}
else
{
if (!(view.CustomSort is ColumnComparer))
{
dataGrid.SetValue(PreviousComparerProperty, view.CustomSort);
}
switch (column.SortDirection)
{
case ListSortDirection.Ascending:
column.SortDirection = ListSortDirection.Descending;
view.CustomSort = columnComparer.Descending;
break;
case null:
case ListSortDirection.Descending:
column.SortDirection = ListSortDirection.Ascending;
view.CustomSort = columnComparer.Ascending;
break;
default:
throw new ArgumentOutOfRangeException();
}
e.Handled = true;
}
}
private class ColumnComparer : IComparer
{
private readonly IComparer valueComparer;
private readonly DataGridColumn column;
private readonly InvertedComparer inverted;
public ColumnComparer(IComparer valueComparer, DataGridColumn column)
{
this.valueComparer = valueComparer;
this.column = column;
inverted = new InvertedComparer(this);
}
public IComparer Ascending => this;
public IComparer Descending => inverted;
int IComparer.Compare(object x, object y)
{
if (x == y)
{
return 0;
}
if (x == null)
{
return -1;
}
if (y == null)
{
return 1;
}
// this can perhaps be a bit slow
// Not adding caching yet.
var xProp = x.GetType().GetProperty(column.SortMemberPath);
var xValue = xProp.GetValue(x);
var yProp = x.GetType().GetProperty(column.SortMemberPath);
var yValue = yProp.GetValue(y);
return valueComparer.Compare(xValue, yValue);
}
private class InvertedComparer : IComparer
{
private readonly IComparer comparer;
public InvertedComparer(IComparer comparer)
{
this.comparer = comparer;
}
public int Compare(object x, object y)
{
return comparer.Compare(y, x);
}
}
}
}
用法:
<DataGrid AutoGenerateColumns="False"
ItemsSource="{Binding DataItems}"
local:DataGridSort.UseCustomSort="True">
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding Key}"
Header="Key"
local:DataGridSort.Comparer="{x:Static local:StringLengthComparer.Default}" />
<DataGridTextColumn Binding="{Binding Value}" Header="Value" />
</DataGrid.Columns>
</DataGrid>