在默认情况下，WPF提供的DataGrid仅拥有数据展示等简单功能，如果要实现像Excel一样复杂的筛选功能，则相对比较麻烦。本文以一个简单的小例子，简述如何通过WPF实话DataGrid的筛选功能，仅供学习分享使用，如有不足之处，还请指正。.
涉及知识点
在本示例中，从数据绑定，到数据展示，涉及知识点如下所示：
DataGrid，要WPF提供的进行二维数据展示在列表控件，默认功能非常简单，但是可以通过数据模板或者控件模板进行扩展和美化，可伸缩性很强。
MVVM，是Model-View-ViewModel的简写，主要进行数据和UI进行前后端分离，在本示例中，主要用到的MVVM第三方库为CommunityToolkit.Mvvm，大大简化原生MVVM的实现方式。
集合视图， 要对 DataGrid 中的数据进行分组、排序和筛选，可以将其绑定到支持这些函数的 CollectionView。然后，可以在不影响基础源数据的情况下处理 CollectionView 中的数据。集合视图中的更改反映在 DataGrid 用户界面 (UI) 中。
Popup控件，直接继承FrameworkElement，提供了一种在单独的窗口中显示内容的方法，该窗口相对于指定的元素或屏幕坐标，浮动在当前Popup应用程序窗口上，可用于悬浮窗口。
示例截图
本示例主要模仿Excel的筛选功能进行实现，右键标题栏打开浮动窗口，悬浮于标题栏下方，既可以通过文本框进行筛选，也可以通过筛选按钮弹出右键菜单，选择具体筛选方式，截图如下所示：
选择筛选方式，弹出窗口，如下所示：
输入筛选条件，点击确定，或者取消筛选。如筛选学号里面包含2的，效果如下所示：
注意：以上筛选都是客户端筛选，不会修改数据源，也不会重连数据库。
核心源码
在本示例中，核心源码主要包含以下几个部分：
前端视图【MainWindow.xaml】源码
主要实现了按学号，姓名，年龄三列进行筛选，既可以单列筛选，又可以组合筛选。且三列的筛选实现方式一致，仅是绑定列有差异。
<Window x:Class="DemoDataGrid.MainWindow"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"xmlns:local="clr-namespace:DemoDataGrid"mc:Ignorable="d"Title="DataGrid筛选示例" Height="650" Width="800"><Window.Resources><ResourceDictionary><CollectionViewSource x:Key="ItemsSource" Source="{Binding Path=Students}"></CollectionViewSource><CollectionViewSource x:Key="Names" Source="{Binding Path=Names}"></CollectionViewSource><CollectionViewSource x:Key="Nos" Source="{Binding Path=Nos}"></CollectionViewSource><CollectionViewSource x:Key="Ages" Source="{Binding Path=Ages}"></CollectionViewSource><Style x:Key="ListBoxStyle" TargetType="{x:Type ListBox}"><Setter Property="ScrollViewer.CanContentScroll" Value="True"></Setter><Setter Property="Template"><Setter.Value><ControlTemplate TargetType="{x:Type ListBox}"><ScrollViewer x:Name="ScrollViewer" CanContentScroll="True"><ItemsPresenter></ItemsPresenter></ScrollViewer></ControlTemplate></Setter.Value></Setter></Style><Geometry x:Key="Icon_Filter">M608 864C588.8 864 576 851.2 576 832L576 448c0-6.4 6.4-19.2 12.8-25.6L787.2 256c6.4-6.4 6.4-19.2 0-19.2 0-6.4-6.4-12.8-19.2-12.8L256 224c-12.8 0-19.2 6.4-19.2 12.8 0 6.4-6.4 12.8 6.4 19.2l198.4 166.4C441.6 428.8 448 441.6 448 448l0 256c0 19.2-12.8 32-32 32S384 723.2 384 704L384 460.8 198.4 307.2c-25.6-25.6-32-64-19.2-96C185.6 179.2 217.6 160 256 160L768 160c32 0 64 19.2 76.8 51.2 12.8 32 6.4 70.4-19.2 89.6l-192 160L633.6 832C640 851.2 627.2 864 608 864z</Geometry><ContextMenu x:Key="queryConditionMenu" MouseLeave="ContextMenu_MouseLeave" MenuItem.Click="ContextMenu_Click"><MenuItem FontSize="12" Header="等于" Tag="Equal"></MenuItem><MenuItem FontSize="12" Header="不等于" Tag="NotEqual"></MenuItem><MenuItem FontSize="12" Header="开头" Tag="Begin"></MenuItem><MenuItem FontSize="12" Header="结尾" Tag="End"></MenuItem><MenuItem FontSize="12" Header="包含" Tag="In"></MenuItem><MenuItem FontSize="12" Header="不包含" Tag="NotIn"></MenuItem></ContextMenu></ResourceDictionary></Window.Resources><Grid Margin="10"><Grid.RowDefinitions><RowDefinition Height="20"></RowDefinition><RowDefinition Height="*"></RowDefinition></Grid.RowDefinitions><DataGrid Grid.Row="1" x:Name="dgStudents" ItemsSource="{Binding Source={StaticResource ItemsSource} }" AutoGenerateColumns="False"CanUserReorderColumns="True" CanUserDeleteRows="False" CanUserAddRows="False" HeadersVisibility="Column"CanUserSortColumns="True"VirtualizingPanel.VirtualizationMode="Recycling"EnableColumnVirtualization="True" VirtualizingPanel.IsVirtualizingWhenGrouping="True" GridLinesVisibility="All" RowHeight="25"SelectionUnit="FullRow" SelectionMode="Single" IsReadOnly="True" FontSize="12"SelectedIndex="{Binding SelectTaskItemIndex}" SelectedItem="{Binding SelectTaskItem}"CanUserResizeColumns="True"><DataGrid.Columns><DataGridTextColumn Binding="{Binding Id}" Header="Id" Width="*"></DataGridTextColumn><DataGridTextColumn Binding="{Binding No}" Width="*"><DataGridTextColumn.Header><TextBlock Text="学号" FontWeight="Regular" MouseRightButtonDown="TextBlock_MouseRightButtonDown" Tag="No"></TextBlock></DataGridTextColumn.Header></DataGridTextColumn><DataGridTextColumn Binding="{Binding Name}" Width="*"><DataGridTextColumn.Header><TextBlock Text="姓名" FontWeight="Regular" MouseRightButtonDown="TextBlock_MouseRightButtonDown" Tag="Name"></TextBlock></DataGridTextColumn.Header></DataGridTextColumn><DataGridTextColumn Binding="{Binding Age}" Width="*"><DataGridTextColumn.Header><TextBlock Text="年龄" FontWeight="Regular" MouseRightButtonDown="TextBlock_MouseRightButtonDown" Tag="Age"></TextBlock></DataGridTextColumn.Header></DataGridTextColumn></DataGrid.Columns></DataGrid><Popup x:Name="popupNo" Width="135" MaxHeight="500" Height="Auto" PopupAnimation="Slide" AllowsTransparency="False" MouseLeave="popup_MouseLeave"><Border BorderBrush="LightBlue" BorderThickness="1" Padding="5" Background="AliceBlue"><Grid><Grid.ColumnDefinitions><ColumnDefinition></ColumnDefinition><ColumnDefinition></ColumnDefinition></Grid.ColumnDefinitions><Grid.RowDefinitions><RowDefinition></RowDefinition><RowDefinition></RowDefinition><RowDefinition></RowDefinition></Grid.RowDefinitions><StackPanel Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" Orientation="Horizontal"><TextBox Height="25" x:Name="txtNo" MinWidth="60" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" Tag="No" TextChanged="TextBox_TextChanged"></TextBox><Button x:Name="btnNoFilter" Tag="No" ClickMode="Press" Click="ButtonFilter_Click" ContextMenu="{StaticResource queryConditionMenu}"><StackPanel Orientation="Horizontal" VerticalAlignment="Center"><Path Data="{StaticResource Icon_Filter}" Stroke="Gray" StrokeThickness="1"Height="12" Width="12" Stretch="Fill"></Path><TextBlock Margin="2,0" Text="筛选" FontSize="12"></TextBlock></StackPanel></Button></StackPanel><ListBox x:Name="lbNos" ItemsSource="{Binding Source={StaticResource Nos}}" Grid.Column="0" Grid.Row="1" Grid.ColumnSpan="2" VirtualizingPanel.VirtualizationMode="Recycling" VirtualizingPanel.IsVirtualizing="True" Style="{StaticResource ListBoxStyle}"><ListBox.ItemTemplate><DataTemplate><CheckBox Content="{Binding FilterText}" IsChecked="{Binding IsChecked}"></CheckBox></DataTemplate></ListBox.ItemTemplate></ListBox><Button Tag="No" Content="取消" Width="60" HorizontalAlignment="Left" Grid.Row="2" Grid.Column="0" Click="btnCancel_Click"></Button><Button Content="确定" Width="60" HorizontalAlignment="Right" Grid.Row="2" Grid.Column="1" Click="btnOk_Click"></Button></Grid></Border></Popup><Popup x:Name="popupName" Width="135" MaxHeight="500" Height="Auto" PopupAnimation="Slide" AllowsTransparency="False" MouseLeave="popup_MouseLeave"><Border BorderBrush="LightBlue" BorderThickness="1" Padding="5" Background="AliceBlue"><Grid><Grid.ColumnDefinitions><ColumnDefinition></ColumnDefinition><ColumnDefinition></ColumnDefinition></Grid.ColumnDefinitions><Grid.RowDefinitions><RowDefinition></RowDefinition><RowDefinition></RowDefinition><RowDefinition></RowDefinition></Grid.RowDefinitions><StackPanel Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" Orientation="Horizontal"><TextBox Height="25" x:Name="txtName" MinWidth="60" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" Tag="Name" TextChanged="TextBox_TextChanged"></TextBox><Button x:Name="btnNameFilter" Tag="Name" Click="ButtonFilter_Click" ContextMenu="{StaticResource queryConditionMenu}"><StackPanel Orientation="Horizontal" VerticalAlignment="Center"><Path Data="{StaticResource Icon_Filter}" Stroke="Gray" StrokeThickness="1"Height="12" Width="12" Stretch="Fill"></Path><TextBlock Margin="2,0" Text="筛选" FontSize="12"></TextBlock></StackPanel></Button></StackPanel><ListBox x:Name="lbNames" ItemsSource="{Binding Source={StaticResource Names}}" Grid.Column="0" Grid.Row="1" Grid.ColumnSpan="2" VirtualizingPanel.VirtualizationMode="Recycling" VirtualizingPanel.IsVirtualizing="True" Style="{StaticResource ListBoxStyle}"><ListBox.ItemTemplate><DataTemplate><CheckBox Content="{Binding FilterText}" IsChecked="{Binding IsChecked}"></CheckBox></DataTemplate></ListBox.ItemTemplate></ListBox><Button Tag="No" Content="取消" Width="60" HorizontalAlignment="Left" Grid.Row="2" Grid.Column="0" Click="btnCancel_Click"></Button><Button Content="确定" Width="60" HorizontalAlignment="Right" Grid.Row="2" Grid.Column="1" Click="btnOk_Click"></Button></Grid></Border></Popup><Popup x:Name="popupAge" Width="135" MaxHeight="500" Height="Auto" PopupAnimation="Slide" AllowsTransparency="False" MouseLeave="popup_MouseLeave"><Border BorderBrush="LightBlue" BorderThickness="1" Padding="5" Background="AliceBlue"><Grid><Grid.ColumnDefinitions><ColumnDefinition></ColumnDefinition><ColumnDefinition></ColumnDefinition></Grid.ColumnDefinitions><Grid.RowDefinitions><RowDefinition></RowDefinition><RowDefinition></RowDefinition><RowDefinition></RowDefinition></Grid.RowDefinitions><StackPanel Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" Orientation="Horizontal"><TextBox Height="25" x:Name="txtAge" MinWidth="60" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" Tag="Age" TextChanged="TextBox_TextChanged"></TextBox><Button x:Name="btnAgeFilter" Tag="Age" Click="ButtonFilter_Click" ContextMenu="{StaticResource queryConditionMenu}"><StackPanel Orientation="Horizontal" VerticalAlignment="Center"><Path Data="{StaticResource Icon_Filter}" Stroke="Gray" StrokeThickness="1"Height="12" Width="12" Stretch="Fill"></Path><TextBlock Margin="2,0" Text="筛选" FontSize="12"></TextBlock></StackPanel></Button></StackPanel><ListBox x:Name="lbAges" ItemsSource="{Binding Source={StaticResource Ages}}" Grid.Column="0" Grid.Row="1" Grid.ColumnSpan="2" VirtualizingPanel.VirtualizationMode="Recycling" VirtualizingPanel.IsVirtualizing="True" Style="{StaticResource ListBoxStyle}"><ListBox.ItemTemplate><DataTemplate><CheckBox Content="{Binding FilterText}" IsChecked="{Binding IsChecked}"></CheckBox></DataTemplate></ListBox.ItemTemplate></ListBox><Button Tag="No" Content="取消" Width="60" HorizontalAlignment="Left" Grid.Row="2" Grid.Column="0" Click="btnCancel_Click"></Button><Button Content="确定" Width="60" HorizontalAlignment="Right" Grid.Row="2" Grid.Column="1" Click="btnOk_Click"></Button></Grid></Border></Popup><Popup x:Name="popupNoMenu" Width="300" MaxHeight="500" Height="200" PopupAnimation="Slide" AllowsTransparency="False" Tag=""><Border BorderThickness="1" BorderBrush="Beige" Padding="15" Background="AliceBlue"><Grid><Grid.ColumnDefinitions><ColumnDefinition></ColumnDefinition><ColumnDefinition></ColumnDefinition></Grid.ColumnDefinitions><Grid.RowDefinitions><RowDefinition Height="Auto"></RowDefinition><RowDefinition Height="Auto"></RowDefinition><RowDefinition Height="Auto"></RowDefinition><RowDefinition></RowDefinition></Grid.RowDefinitions><StackPanel Orientation="Horizontal" Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="2"><TextBlock Text="学号" VerticalAlignment="Center"></TextBlock><ComboBox x:Name="combNoMenu1" Height="28" Width="100" Margin="4" VerticalContentAlignment="Center"><ComboBoxItem Content="等于" ></ComboBoxItem><ComboBoxItem Content="不等于"></ComboBoxItem><ComboBoxItem Content="开头"></ComboBoxItem><ComboBoxItem Content="结尾"></ComboBoxItem><ComboBoxItem Content="包含"></ComboBoxItem><ComboBoxItem Content="不包含"></ComboBoxItem></ComboBox><TextBox x:Name="txtNoMenu1" Height="28" Width="100" VerticalContentAlignment="Center"></TextBox></StackPanel><StackPanel Orientation="Horizontal" Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2"><RadioButton x:Name="rbNoAnd" Content="与" IsChecked="True" Margin="4" Background="AliceBlue" VerticalAlignment="Center" VerticalContentAlignment="Center"></RadioButton><RadioButton x:Name="rbNoOr" Content="或" Background="AliceBlue" VerticalAlignment="Center" VerticalContentAlignment="Center"></RadioButton></StackPanel><StackPanel Orientation="Horizontal" Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="2"><TextBlock Text="学号" VerticalAlignment="Center"></TextBlock><ComboBox x:Name="combNoMenu2" Height="28" Margin="4" Width="100" VerticalContentAlignment="Center"><ComboBoxItem Content="等于" ></ComboBoxItem><ComboBoxItem Content="不等于"></ComboBoxItem><ComboBoxItem Content="开头"></ComboBoxItem><ComboBoxItem Content="结尾"></ComboBoxItem><ComboBoxItem Content="包含"></ComboBoxItem><ComboBoxItem Content="不包含"></ComboBoxItem></ComboBox><TextBox x:Name="txtNoMenu2" Height="28" Width="100" VerticalContentAlignment="Center"></TextBox></StackPanel><Button Tag="No" Content="取消" Width="100" Height="28" HorizontalAlignment="Left" Grid.Row="3" Grid.Column="0" Click="btnCancelFilter_Click"></Button><Button Tag="No" Content="确定" Width="100" Height="28" HorizontalAlignment="Right" Grid.Row="3" Grid.Column="1" Click="btnOkFilter_Click"></Button></Grid></Border></Popup><Popup x:Name="popupNameMenu" Width="300" MaxHeight="500" Height="200" PopupAnimation="Slide" AllowsTransparency="False" Tag=""><Border BorderThickness="1" BorderBrush="Beige" Padding="15" Background="AliceBlue"><Grid><Grid.RowDefinitions><RowDefinition Height="Auto"></RowDefinition><RowDefinition Height="Auto"></RowDefinition><RowDefinition Height="Auto"></RowDefinition><RowDefinition Height="Auto"></RowDefinition></Grid.RowDefinitions><StackPanel Orientation="Horizontal" Grid.Row="0" Grid.Column="0"><TextBlock Text="姓名" VerticalAlignment="Center"></TextBlock><ComboBox x:Name="combNameMenu1" Height="28" Width="100" Margin="4" VerticalContentAlignment="Center"><ComboBoxItem Content="等于" ></ComboBoxItem><ComboBoxItem Content="不等于"></ComboBoxItem><ComboBoxItem Content="开头"></ComboBoxItem><ComboBoxItem Content="结尾"></ComboBoxItem><ComboBoxItem Content="包含"></ComboBoxItem><ComboBoxItem Content="不包含"></ComboBoxItem></ComboBox><TextBox x:Name="txtNameMenu1" Height="28" Width="100" VerticalContentAlignment="Center"></TextBox></StackPanel><StackPanel Orientation="Horizontal" Grid.Row="1" Grid.Column="0"><RadioButton x:Name="rbNameAnd" Content="与" IsChecked="True" Margin="4" Background="AliceBlue" VerticalAlignment="Center" VerticalContentAlignment="Center"></RadioButton><RadioButton x:Name="rbNameOr" Content="或" Background="AliceBlue" VerticalAlignment="Center" VerticalContentAlignment="Center"></RadioButton></StackPanel><StackPanel Orientation="Horizontal" Grid.Row="2" Grid.Column="0"><TextBlock Text="姓名" VerticalAlignment="Center"></TextBlock><ComboBox x:Name="combNameMenu2" Height="28" Width="100" Margin="4" VerticalContentAlignment="Center"><ComboBoxItem Content="等于" ></ComboBoxItem><ComboBoxItem Content="不等于"></ComboBoxItem><ComboBoxItem Content="开头"></ComboBoxItem><ComboBoxItem Content="结尾"></ComboBoxItem><ComboBoxItem Content="包含"></ComboBoxItem><ComboBoxItem Content="不包含"></ComboBoxItem></ComboBox><TextBox x:Name="txtNameMenu2" Height="28" Width="100" VerticalContentAlignment="Center"></TextBox></StackPanel><Button Tag="Name" Content="取消" Width="100" Height="28" HorizontalAlignment="Left" Grid.Row="3" Grid.Column="0" Click="btnCancelFilter_Click"></Button><Button Tag="Name" Content="确定" Width="100" Height="28" HorizontalAlignment="Right" Grid.Row="3" Grid.Column="1" Click="btnOkFilter_Click"></Button></Grid></Border></Popup><Popup x:Name="popupAgeMenu" Width="300" MaxHeight="500" Height="200" PopupAnimation="Slide" AllowsTransparency="False" Tag=""><Border BorderThickness="1" BorderBrush="Beige" Padding="15" Background="AliceBlue"><Grid><Grid.RowDefinitions><RowDefinition Height="Auto"></RowDefinition><RowDefinition Height="Auto"></RowDefinition><RowDefinition Height="Auto"></RowDefinition><RowDefinition Height="Auto"></RowDefinition></Grid.RowDefinitions><StackPanel Orientation="Horizontal" Grid.Row="0" Grid.Column="0"><TextBlock Text="年龄" VerticalAlignment="Center"></TextBlock><ComboBox x:Name="combAgeMenu1" Height="28" Width="100" Margin="4" VerticalContentAlignment="Center"><ComboBoxItem Content="等于" ></ComboBoxItem><ComboBoxItem Content="不等于"></ComboBoxItem><ComboBoxItem Content="开头"></ComboBoxItem><ComboBoxItem Content="结尾"></ComboBoxItem><ComboBoxItem Content="包含"></ComboBoxItem><ComboBoxItem Content="不包含"></ComboBoxItem></ComboBox><TextBox x:Name="txtAgeMenu1" Height="28" Width="100" VerticalContentAlignment="Center"></TextBox></StackPanel><StackPanel Orientation="Horizontal" Grid.Row="1" Grid.Column="0"><RadioButton x:Name="rbAgeAnd" Content="与" IsChecked="True" Margin="4" Background="AliceBlue" VerticalAlignment="Center" VerticalContentAlignment="Center"></RadioButton><RadioButton x:Name="rbAgeOr" Content="或" Background="AliceBlue" VerticalAlignment="Center" VerticalContentAlignment="Center"></RadioButton></StackPanel><StackPanel Orientation="Horizontal" Grid.Row="2" Grid.Column="0"><TextBlock Text="年龄" VerticalAlignment="Center"></TextBlock><ComboBox x:Name="combAgeMenu2" Height="28" Width="100" Margin="4" VerticalContentAlignment="Center"><ComboBoxItem Content="等于" ></ComboBoxItem><ComboBoxItem Content="不等于"></ComboBoxItem><ComboBoxItem Content="开头"></ComboBoxItem><ComboBoxItem Content="结尾"></ComboBoxItem><ComboBoxItem Content="包含"></ComboBoxItem><ComboBoxItem Content="不包含"></ComboBoxItem></ComboBox><TextBox x:Name="txtAgeMenu2" Height="28" Width="100" VerticalContentAlignment="Center"></TextBox></StackPanel><Button Tag="Age" Content="取消" Width="100" Height="28" HorizontalAlignment="Left" Grid.Row="3" Grid.Column="0" Click="btnCancelFilter_Click"></Button><Button Tag="Age" Content="确定" Width="100" Height="28" HorizontalAlignment="Right" Grid.Row="3" Grid.Column="1" Click="btnOkFilter_Click"></Button></Grid></Border></Popup></Grid></Window>
业务逻辑【MainWindowViewModel】
业务逻辑处理主要复责数据初始化等业务相关内容，和UI无关，如下所示：
using CommunityToolkit.Mvvm.ComponentModel;using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace DemoDataGrid{public class MainWindowViewModel:ObservableObject{#region 属性及构造函数private List<Student> students;public List<Student> Students{get { return students; }set { SetProperty(ref students, value); }}private List<FilterInfo> names;public List<FilterInfo> Names{get { return names; }set { SetProperty(ref names, value); }}private List<FilterInfo> nos;public List<FilterInfo> Nos{get { return nos; }set {SetProperty(ref nos , value); }}private List<FilterInfo> ages;public List<FilterInfo> Ages{get { return ages; }set {SetProperty(ref ages , value); }}public MainWindowViewModel(){this.Students= new List<Student>();for (int i = 0; i < 20; i++) {this.Students.Add(new Student(){Id = i,Name = $"张{i}牛",Age = (i % 10) + 10,No = i.ToString().PadLeft(4, '0'),});}this.Nos= new List<FilterInfo>();this.Names= new List<FilterInfo>();this.Ages= new List<FilterInfo>();this.Students.ForEach(s => {this.Nos.Add(new FilterInfo() { FilterText=s.No,IsChecked=false });this.Names.Add(new FilterInfo() { FilterText = s.Name, IsChecked = false });this.Ages.Add(new FilterInfo() { FilterText = s.Age.ToString(), IsChecked = false });});this.Ages=this.Ages.Distinct().ToList();//去重}#endregion}}
筛选功能实现【MainWindow.xaml.cs】
本示例为了简化实现，筛选功能处理主要在cs后端实现，如下所示：
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows;using System.Windows.Controls;using System.Windows.Data;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Imaging;using System.Windows.Navigation;using System.Windows.Shapes;namespace DemoDataGrid{/// <summary>/// Interaction logic for MainWindow.xaml/// </summary>public partial class MainWindow : Window{private MainWindowViewModel viewModel;public MainWindow(){InitializeComponent();viewModel = new MainWindowViewModel();this.DataContext = viewModel;}#region 筛选private void TextBlock_MouseRightButtonDown(object sender, MouseButtonEventArgs e){if (sender != null && sender is TextBlock){var textBlock = sender as TextBlock;var tag = textBlock.Tag.ToString();var pop = this.FindName($"popup{tag}");if (pop != null){var popup = pop as System.Windows.Controls.Primitives.Popup;if (popup != null){popup.IsOpen = true;popup.PlacementTarget = textBlock;popup.Placement = System.Windows.Controls.Primitives.PlacementMode.RelativePoint;popup.VerticalOffset = 10;popup.HorizontalOffset = 10;}}}}private void TextBox_TextChanged(object sender, TextChangedEventArgs e){TextBox textBox = e.OriginalSource as TextBox;var tag = textBox.Tag;//条件var text = textBox.Text;if (tag != null){if (tag.ToString() == "No"){Filter(this.lbNos.ItemsSource, this.txtNo.Text);}if (tag.ToString() == "Name"){Filter(this.lbNames.ItemsSource, this.txtName.Text);}if (tag.ToString() == "Age"){Filter(this.lbAges.ItemsSource, this.txtAge.Text);}}}private void Filter(object source, string filter){var cv = CollectionViewSource.GetDefaultView(source);if (cv != null && cv.CanFilter){cv.Filter = new Predicate<object>((obj) => {bool flag = true;var t = obj as FilterInfo;if (t != null){flag = t.FilterText.Contains(filter);}return flag;});}}private void popup_MouseLeave(object sender, MouseEventArgs e){var popup = e.OriginalSource as System.Windows.Controls.Primitives.Popup;var showContext = (this.FindResource("queryConditionMenu") as ContextMenu)?.IsOpen;if (popup != null && showContext==false){popup.IsOpen = false;}}private void btnCancel_Click(object sender, RoutedEventArgs e){var btn = e.OriginalSource as Button;if (btn != null){var tag = btn.Tag;if (tag.ToString() == "No"){ClearFilter(this.txtNo, this.viewModel.Nos);}if (tag.ToString() == "Name"){ClearFilter(this.txtName, this.viewModel.Names);}if (tag.ToString() == "Age"){ClearFilter(this.txtAge, this.viewModel.Ages);}FilterTask();//清除以后，重新刷新}}private void ClearFilter(TextBox textBox, List<FilterInfo> collection){textBox.Clear();foreach (var f in collection){f.IsChecked = false;}}private void btnOk_Click(object sender, RoutedEventArgs e){//FilterTask();}private void FilterTask(){var cv = CollectionViewSource.GetDefaultView(this.dgStudents.ItemsSource);if (cv != null && cv.CanFilter){cv.Filter = new Predicate<object>((obj) =>{bool flag = true;var t = obj as Student;if (t != null){var nos = this.viewModel.Nos.Where(r => r.IsChecked == true).ToList();var names = this.viewModel.Names.Where(r => r.IsChecked == true).ToList();var ages = this.viewModel.Ages.Where(r => r.IsChecked == true).ToList();if (nos.Count() > 0){flag = flag && nos.Select(r => r.FilterText).Contains(t.No);}if (names.Count() > 0){flag = flag && names.Select(r => r.FilterText).Contains(t.Name);}if (ages.Count() > 0){flag = flag && ages.Select(r => r.FilterText).Contains(t.Age.ToString());}}return flag;});}}#endregionprivate List<string> condition = new List<string>() { "Equal", "NotEqual", "Begin", "End", "In", "NotIn" };private void ButtonFilter_Click(object sender, RoutedEventArgs e){var btn = e.OriginalSource as Button;if (btn != null){var tag = btn.Tag;var popup = this.FindName($"popup{tag}") as System.Windows.Controls.Primitives.Popup;if (popup != null){popup.IsOpen = true;}if (btn.ContextMenu.IsOpen){btn.ContextMenu.IsOpen = false;}else{btn.ContextMenu.Tag = tag;btn.ContextMenu.Width = 100;btn.ContextMenu.Height = 150;btn.ContextMenu.IsOpen = true;btn.ContextMenu.PlacementTarget = btn;btn.ContextMenu.Placement = System.Windows.Controls.Primitives.PlacementMode.Bottom;}}}private void ContextMenu_MouseLeave(object sender, MouseEventArgs e){var menu = e.OriginalSource as ContextMenu;if (menu != null){menu.IsOpen = false;}}private void ContextMenu_Click(object sender, RoutedEventArgs e){var contextMenu = sender as ContextMenu;if (contextMenu == null){return;}var menuItem = e.OriginalSource as MenuItem;if (menuItem == null){return;}var tag1 = contextMenu.Tag.ToString();//点击的哪一个按钮var tag2 = menuItem.Tag.ToString();//点击的是哪一个菜单var pop = this.FindName($"popup{tag1}Menu");var comb = this.FindName($"comb{tag1}Menu1");HideParentPopup(tag1);//隐藏父Popupif (comb != null){var combMenu = comb as ComboBox;combMenu.SelectedIndex = condition.IndexOf(tag2);}if (pop != null){var popup = pop as System.Windows.Controls.Primitives.Popup;popup.IsOpen = true;popup.PlacementTarget = dgStudents;popup.Placement = System.Windows.Controls.Primitives.PlacementMode.Center;}}private void btnCancelFilter_Click(object sender, RoutedEventArgs e){if (sender == null){return;}var btn = sender as System.Windows.Controls.Button;if (btn != null){var tag = btn.Tag.ToString();HidePopupMenu(tag);//隐藏Popup控件if (tag == "No"){ClearMenuFilter(this.txtNoMenu1, this.txtNoMenu2);}if (tag == "Name"){ClearMenuFilter(this.txtNameMenu1, this.txtNameMenu2);}if (tag == "Age"){ClearMenuFilter(this.txtAgeMenu1, this.txtAgeMenu2);}FilterMenuTask();}}private void btnOkFilter_Click(object sender, RoutedEventArgs e){if (sender == null){return;}var btn = sender as System.Windows.Controls.Button;if (btn != null){var tag = btn.Tag.ToString();HidePopupMenu(tag);FilterMenuTask();}}/// <summary>/// 隐藏父Popup/// </summary>/// <param name="tag"></param>private void HideParentPopup(string tag){//点击右键菜单时，隐藏父Popup控件if (tag == "No"){this.popupNo.IsOpen = false;}if (tag == "Name"){this.popupName.IsOpen = false;}if (tag == "Age"){this.popupAge.IsOpen = false;}}/// <summary>/// 隐藏菜单弹出的Popup控件/// </summary>/// <param name="tag"></param>private void HidePopupMenu(string tag){var pop = this.FindName($"popup{tag}Menu");if (pop != null){var popup = pop as System.Windows.Controls.Primitives.Popup;popup.IsOpen = false;}}/// <summary>/// 清除菜单中的文本过滤条件/// </summary>/// <param name="txt1"></param>/// <param name="txt2"></param>private void ClearMenuFilter(TextBox txt1, TextBox txt2){txt1?.Clear();txt2?.Clear();}/// <summary>////// </summary>private void FilterMenuTask(){var cv = CollectionViewSource.GetDefaultView(this.dgStudents.ItemsSource);if (cv != null && cv.CanFilter){cv.Filter = new Predicate<object>((obj) =>{bool flag = true;var t = obj as Student;if (t != null){string noText1 = this.txtNoMenu1.Text.Trim();string noText2 = this.txtNoMenu2.Text.Trim();int noConditionType1 = this.combNoMenu1.SelectedIndex;int noConditionType2 = this.combNoMenu2.SelectedIndex;string nameText1 = this.txtNameMenu1.Text.Trim();string nameText2 = this.txtNameMenu2.Text.Trim();int nameConditionType1 = this.combNameMenu1.SelectedIndex;int nameConditionType2 = this.combNameMenu2.SelectedIndex;string ageText1 = this.txtAgeMenu1.Text.Trim();string ageText2 = this.txtAgeMenu2.Text.Trim();int ageConditionType1 = this.combAgeMenu1.SelectedIndex;int ageConditionType2 = this.combAgeMenu2.SelectedIndex;bool? isNoAnd = this.rbNoAnd.IsChecked;bool? isNoOr = this.rbNoOr.IsChecked;bool? isNameAnd = this.rbNameAnd.IsChecked;bool? isNameOr = this.rbNameOr.IsChecked;bool? isAgeAnd = this.rbAgeAnd.IsChecked;bool? isAgeOr = this.rbAgeOr.IsChecked;bool flagNo = true;bool flagName = true;bool flagAge = true;flagNo = CheckConditions(noConditionType1, noConditionType2, t.No, noText1, noText2, isNoAnd, isNoOr);flagName = CheckConditions(nameConditionType1, nameConditionType2, t.Name, nameText1, nameText2, isNameAnd, isNameOr);flagAge = CheckConditions(ageConditionType1, ageConditionType2, t.Age.ToString(), ageText1, ageText2, isAgeAnd, isAgeOr);flag = flag && flagNo && flagName && flagAge;}return flag;});}}private bool CheckConditions(int conditionIndex1, int conditionIndex2, string source, string condition1, string condition2, bool? isAnd, bool? isOr){bool flag = true;bool flag1 = true;bool flag2 = true;if (!string.IsNullOrEmpty(condition1) && !string.IsNullOrWhiteSpace(condition1) && conditionIndex1 != -1){flag1 = CheckCondition(conditionIndex1, source, condition1);}if (!string.IsNullOrEmpty(condition2) && !string.IsNullOrWhiteSpace(condition2) && conditionIndex2 != -1){flag2 = CheckCondition(conditionIndex2, source, condition2);}if (isAnd == true){flag = flag1 && flag2;}if (isOr == true){flag = flag1 || flag2;}return flag;}private bool CheckCondition(int condtionIndex, string source, string condition){bool flag = true;if (condtionIndex == 0){flag = flag && source == condition;}if (condtionIndex == 1){flag = flag && source != condition;}if (condtionIndex == 2){flag = flag && source.StartsWith(condition);}if (condtionIndex == 3){flag = flag && source.EndsWith(condition);}if (condtionIndex == 4){flag = flag && source.Contains(condition);}if (condtionIndex == 5){flag = flag && !source.Contains(condition);}return flag;}}}
学号，姓名，年龄三列过滤列表绑定内容模型一致，为FilterInfo，如下所示：
using CommunityToolkit.Mvvm.ComponentModel;using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace DemoDataGrid{public class FilterInfo : ObservableObject{private string filterText;public string FilterText{get { return filterText; }set { SetProperty(ref filterText, value); }}private bool isChecked;public bool IsChecked{get { return isChecked; }set { SetProperty(ref isChecked, value); }}}}
不足与思考
上述筛选实现方式，并非唯一实现，也并非最优实现，同样存在许多可以优化的地方。
在本示例中，存在许多冗余代码，如视图页面，对三列的弹出窗口，内容虽然相对统一，只是列名和绑定内容不同而已，却堆积了三大段代码，是否可以从控件模块或者数据模板的角度，进行简化呢？
筛选功能实现上，同样存在许多冗余代码，是否可以进行简化呢？以上是我们需要思考的地方，希望可以集思广益，共同学习，一起进步。
