WPF DataGrid 过滤 - CollectionViewSource 刷新

使用 WPF DataGrid 进行数据展示和过滤是非常常见的需求。在实际开发中，我们经常需要根据用户的输入来动态地过滤数据，并在用户改变过滤条件时及时刷新展示的结果。本文将介绍如何使用 CollectionViewSource 来实现 WPF DataGrid 的过滤功能，并通过一个案例代码来进行演示。

xaml
    

xaml

csharp
private void OnFilter(object sender, FilterEventArgs e)
{
    Student student = e.Item as Student;
    if (student != null)
    {
        if (string.IsNullOrEmpty(FilterText))
        {
            e.Accepted = true;
        }
        else
        {
            if (student.Name.Contains(FilterText))
            {
                e.Accepted = true;
            }
            else
            {
                e.Accepted = false;
            }
        }
    }
}

csharp
private void OnFilterTextChanged(object sender, TextChangedEventArgs e)
{
    CollectionViewSource.GetDefaultView(Students).Refresh();
}

xaml
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="450" Width="800">
    
        
    
    
        
    

csharp
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows;
namespace WpfApp
{
    public partial class MainWindow : Window, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        private ObservableCollection _students;
        private string _filterText;
        public ObservableCollection Students
        {
            get { return _students; }
            set
            {
                _students = value;
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Students)));
            }
        }
        public string FilterText
        {
            get { return _filterText; }
            set
            {
                _filterText = value;
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(FilterText)));
            }
        }
        public MainWindow()
        {
            InitializeComponent();
            Students = new ObservableCollection
            {
                new Student { Name = "Alice" },
                new Student { Name = "Bob" },
                new Student { Name = "Charlie" },
                new Student { Name = "David" },
                new Student { Name = "Emily" }
            };
            CollectionViewSource.GetDefaultView(Students).Filter += OnFilter;
        }
        private void OnFilter(object sender, FilterEventArgs e)
        {
            Student student = e.Item as Student;
            if (student != null)
            {
                if (string.IsNullOrEmpty(FilterText))
                {
                    e.Accepted = true;
                }
                else
                {
                    if (student.Name.Contains(FilterText))
                    {
                        e.Accepted = true;
                    }
                    else
                    {
                        e.Accepted = false;
                    }
                }
            }
        }
        private void OnFilterTextChanged(object sender, TextChangedEventArgs e)
        {
            CollectionViewSource.GetDefaultView(Students).Refresh();
        }
    }
    public class Student
    {
        public string Name { get; set; }
    }
}