WPF DataGrid 服务端排序
转载：http://www.kecq.com/artic-10322303.html
以前做了一个数据客户端，不过是直接连数据库的，现在认为这种方式不太好，于是改成服务端RESTful API+客户端，数据处理都在服务端。在编写过程中遇到一些问题，因为之前没有采用分页，所以排序就用DataGrid默认的就行，但是现在需要在服务端分页了，就发现了一些问题，记录下来。
在XAML中有一个名为dataGrid1的DataGrid，点击列头排序只需要在上面加上Sorting属性
初始化的时候可以为某一列指定排序
ICollectionView view = CollectionViewSource.GetDefaultView(list);
view.SortDescriptions.Clear(); //先清除所有的排序
SortDescription sd = new SortDescription("列名", ListSortDirection.Descending);
view.SortDescriptions.Add(sd);
也可以在XAML中指定，假设列名是movieName
下面来看主要排序方法
private void dataGrid1_Sorting(object sender, DataGridSortingEventArgs e) { e.Handled = true; //可要可不要 没去仔细研究 pager.OrderColumn = e.Column.SortMemberPath; ICollectionView view = CollectionViewSource.GetDefaultView(dataGrid1.ItemsSource); pager.Order = "asc"; //默认升序 if (view.SortDescriptions.Count>0) { if(view.SortDescriptions[0].PropertyName== e.Column.SortMemberPath) { if (view.SortDescriptions[0].Direction == System.ComponentModel.ListSortDirection.Ascending) { pager.Order = "desc"; } else if (view.SortDescriptions[0].Direction == ListSortDirection.Descending) { pager.Order = "asc"; } } } LoadData(); }
e.Column.SortMemberPath 为点击列头的列名，问题就在e.Column.SortDirection 这个属性，如果初始化的时候有指定那么第一次点击的时候能获取到，但是再点击这个属性就是null了,没有指定也是null,好了，我在这里为它赋值e.Column.SortDirection=ListSortDirection.Descending 但是下次点击的时候它还是为null 不知为何，网上没有查到。经过好久摸索，用另一个方法来
ICollectionView view = CollectionViewSource.GetDefaultView(dataGrid1.ItemsSource);
可以从view.SortDescriptions 中取得有排序的列，判断它集合大于0并且列名是当前点击的列，如果当前是升序则变为降序同时查询降序的数据，当然最后还得执行清除排序再添加排序
view.SortDescriptions.Clear(); //先清除所有的排序 SortDescription sd = new SortDescription("列名", ListSortDirection.Descending); view.SortDescriptions.Add(sd);
这样就实现了服务端排序，不知有无更简单的方法。
补充：
文中提到：我在这里为它赋值e.Column.SortDirection=ListSortDirection.Descending，。这里实际效果重新绑定数据后会丢失以前的排序。应该在绑定数据后再重新绑定列的排序状态
所以我这里这样处理的，
1、后端记录上次的排序状态 某列名 升序还是降序
2、绑定数据后，再次赋值当前的排序状态。swich记录的当前排序也就是重新绑定数据前的排序，case某列的排序状态，然后gridResult2.Columns[2].SortDirection重新设置此列的排序状态值。这样就能在?DataGridSortingEventArgs e ? e.Column.SortDirection 属性中获取到重新设置的排序值。这样重新赋值，也能显示自带的排序小箭头。不明白的可以联系www.kaishanguai.com或qq369628105?
switch (CurrentOrderByEnum)
{
case (OrderByEnum.OrderByNameAsc):
gridResult2.Columns[2].SortDirection = ListSortDirection.Ascending;
break;
case (OrderByEnum.OrderByNameDesc):
gridResult2.Columns[2].SortDirection = ListSortDirection.Descending;
break;
?
}?
代码：
"gridResult2" SelectionUnit="FullRow" MinHeight="420" EnableRowVirtualization ="False" GridLinesVisibility="None" BorderThickness="0" AlternationCount="2" ItemsSource="{Binding}" CanUserAddRows="False" HorizontalAlignment="Left" VerticalAlignment="Top" AutoGenerateColumns="False" Visibility="Hidden" IsReadOnly="True" SelectionMode="Extended" Sorting="GridResult2_OnSorting" MouseMove="GridResult2_OnMouseMove" MouseLeftButtonDown="GridResult2_OnMouseLeftButtonDown" MouseLeftButtonUp="GridResult2_OnMouseLeftButtonUp" MouseRightButtonUp="ImageGrid_OnMouseRightButtonDown" LoadingRow="GridResult2_OnLoadingRow" KeyDown="DataView_OnKeyDown" PreviewKeyDown="GridResult2_OnPreviewKeyDown"> "Copy" Executed="CopyCommand" /> "C" Modifiers="Control" Command="Copy" /> "ChkAll" ToolTip="All" Content="All" IsChecked="False" Unchecked="UnAll_Checked" Checked="All_Checked"> "ItemFile_OnChecked" Unchecked="ItemFile_OnUnchecked" Tag="{Binding FilePath}" HorizontalAlignment="Center" x:Name="itemFile" VerticalAlignment="Center" /> ""> "{Binding SnapshotPath}" Height="20" Width="20" /> "Name" Binding="{Binding FileName}" /> "MD5"> "Center" Text="{Binding FileMD5}"> "Modified Date" CanUserSort="True" SortMemberPath="FileModifiedTime"> "Center" Text="{Binding FileModifiedTime}"> "Path" Binding="{Binding FilePathNoName}" /> "Classify Type" CanUserSort="True" SortMemberPath="ClassifyType"> "Center" Text="{Binding ClassifyType}"> "Type"> "Center" Text="{Binding FileExtension}"> "Size(KB)" CanUserSort="True" SortMemberPath="FileSize"> "Center" Text="{Binding FileSize, StringFormat={}{0:N0}}">
//绑定数据后，重新设置排序状态
gridResult2.ItemsSource = bindDataList; //设置排序图标 if (IsClickSort) { switch (CurrentOrderByEnum) { case (OrderByEnum.OrderByNameAsc): gridResult2.Columns[2].SortDirection = ListSortDirection.Ascending ; break; case (OrderByEnum.OrderByNameDesc): gridResult2.Columns[2].SortDirection = ListSortDirection.Descending; break; case (OrderByEnum.OrderByModifiedDateAsc): gridResult2.Columns[4].SortDirection = ListSortDirection.Ascending ; break; case (OrderByEnum.OrderByModifiedDateDesc): gridResult2.Columns[4].SortDirection = ListSortDirection.Descending; break; case (OrderByEnum.OrderByClassifyAsc): gridResult2.Columns[6].SortDirection = ListSortDirection.Ascending; break; case (OrderByEnum.OrderByClassifyDesc): gridResult2.Columns[6].SortDirection = ListSortDirection.Descending ; break; case (OrderByEnum.OrderBySizeAsc): gridResult2.Columns[8].SortDirection = ListSortDirection.Ascending; break; case (OrderByEnum.OrderBySizeDesc): gridResult2.Columns[8].SortDirection = ListSortDirection.Descending; break; } } else { gridResult2.Columns[4].SortDirection = ListSortDirection.Descending; }
//排序事件
private void GridResult2_OnSorting(object sender, DataGridSortingEventArgs e) { ListSortDirection direction = (e.Column.SortDirection != ListSortDirection.Ascending) ? ListSortDirection.Ascending : ListSortDirection.Descending; bool sortAscending = direction == ListSortDirection.Ascending; switch (e.Column.SortMemberPath) { case ("FileName"): if (sortAscending) { CurrentOrderByEnum = OrderByEnum.OrderByNameAsc; } else { CurrentOrderByEnum = OrderByEnum.OrderByNameDesc; } break; case ("FileModifiedTime"): if (sortAscending) { CurrentOrderByEnum = OrderByEnum.OrderByModifiedDateAsc; } else { CurrentOrderByEnum = OrderByEnum.OrderByModifiedDateDesc; } break; case ("ClassifyType"): if (sortAscending) { CurrentOrderByEnum = OrderByEnum.OrderByClassifyAsc; } else { CurrentOrderByEnum = OrderByEnum.OrderByClassifyDesc; } break; case ("FileSize"): if (sortAscending) { CurrentOrderByEnum = OrderByEnum.OrderBySizeAsc; } else { CurrentOrderByEnum = OrderByEnum.OrderBySizeDesc; } break; } IsClickSort = true; Search(); }