将 ListView 绑定到 ObservableCollection 和 Linq

Question

嗨，我正在尝试将 ListView 绑定到 Linq，并使其对集合中的更改做出反应。

public partial class MainWindow
{
    readonly ObservableCollection<Person> _persons = new ObservableCollection<Person>();
    readonly Team _team1 = new Team { Name = "Team 1" };
    readonly Team _team2 = new Team { Name = "Team 2" };
    readonly Team _team3 = new Team { Name = "Team 3" };

    public MainWindow()
    {
        InitializeComponent();

        _persons.Add(new Person {Name = "James", Team = _team1});
        _persons.Add(new Person {Name = "John", Team = _team2});
        _persons.Add(new Person {Name = "Peter", Team = _team3});
        _persons.Add(new Person {Name = "Jack", Team = _team1});
        _persons.Add(new Person {Name = "Jones", Team = _team2});
        _persons.Add(new Person {Name = "Bauer", Team = _team3});
        _persons.Add(new Person {Name = "Bo", Team = _team1});
        _persons.Add(new Person {Name = "Ben", Team = _team2});
        _persons.Add(new Person {Name = "Henry", Team = _team3});

        TeamList1.ItemsSource = from person in _persons where person.Team == _team1 select person;
        TeamList2.ItemsSource = from person in _persons where person.Team == _team2 select person;
        TeamList3.ItemsSource = from person in _persons where person.Team == _team3 select person;
    }

    private void ButtonClick(object sender, RoutedEventArgs e)
    {
        _persons[0].Team = _team2;
    }
}

还有我的模特

 public class Person : INotifyPropertyChanged
    {
        private string _name;
        public String Name
        {
            get { return _name; }
            set { _name = value; NotifyPropertyChanged("Name"); }
        }

        private Team _team;
        public Team Team
        {
            get { return _team; }
            set { _team = value; NotifyPropertyChanged("Team"); }
        }

        public override string ToString()
        {
            return string.Format("Name {0}\t{1}", Name, Team);
        }
        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }
    }

    public class Team : INotifyPropertyChanged
    {
        private string _name;
        public string Name
        {
            get { return _name; }
            set { _name = value; NotifyPropertyChanged("Name"); }
        }

        public override string ToString()
        {
            return Name;
        }
        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }
    }

和 Xaml

<Grid>
        <StackPanel Orientation="Vertical">
        <StackPanel>
            <ListView Name="TeamList1"/>
            <ListView Name="TeamList2"/>
            <ListView Name="TeamList3"/>
        </StackPanel>
            <Button Content="Click Me" Click="ButtonClick"/>
        </StackPanel>
    </Grid>

当调用 ButtonClick 时，我希望我的 ListView 反映它对 _persons 所做的更改。

Answer 1

只是不要使用 linq，这类东西有CollectionViews有过滤器，然后你只需要刷新视图（请参阅：如何：在视图中过滤数据）。 （如果您必须使用 linq，还有可绑定的扩展）

Answer 2

LINQ 查询在绑定到数据源并生成列表视图中的项目时进行评估。 每当您更改原始列表_persons人员的属性时，都不会重新评估 LINQ 查询。 要实现这一点，您必须执行一个自定义实现来侦听原始列表中每个Person的PropertyChanged事件并相应地更新ObservableCollection<Person> 。 您将绑定到列表视图的这个 observable 集合。

Answer 3

你需要我的ObservableComputations库。 使用这个库，你可以这样编码：

    TeamList1.ItemsSource = _persons.Filtering(person.Team == _team1);
    TeamList2.ItemsSource = _persons.Filtering(person.Team == _team2);
    TeamList3.ItemsSource = _persons.Filtering(person.Team == _team3);