需要手动将 observablecollection 填充到列表视图或任何可以显示数据的元素中

Question

正如问题所说，我一直在用我的内容填充数据容器 (listview)，希望有人能告诉我！

这是我拥有的类（我的搜索框发送了一个我想在数据库中查找的参数名称，对我的数据库的查询填充并检索了一个 ObservableCollection，其中填充了尽可能多的参数，然后我想把它显示到我的列表视图中，希望有人能帮助我！提前致谢！）

public class LobbyUserViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }

    private DbOperations.DbOperations db;
    private ObservableCollection<Person> persons;

    public LobbyUserViewModel()
    {
        persons = new ObservableCollection<Person>();
        db = new DbOperations.DbOperations();
        searchPersonCommand = new RelayCommand(SearchPerson, CanSearchPerson);            
    }

    public ICommand SearchPersonCommand
    {
        get { return searchPersonCommand; }
    }

    public bool CanSearchPerson(object obj)
    {
        if (SearchPersonBox != string.Empty)
            return true;
        return false;
    }

    public void SearchPerson(object obj)
    {
        Persons = db.DadosForSearchPerson(searchPerson);
        if (Persons != null)
        {
            foreach (var item in Persons)
            {
                MessageBox.Show(item.Name + " - " + item.Email);
                // This works, but I need these 2 items added on a listview
            }
        }
        else
        {
            MessageBox.Show("Noone found with that name");
        }
    }

    public string SearchPersonBox
    {
        get { return searchPerson.Name; }
        set
        {
            searchPerson.Name = value;
            OnPropertyChanged("SearchPerson");
        }
    }
    public ObservableCollection<Person> Persons
    {
        get { return persons; }
        set { persons = value; }
    }

Answer 1

您需要在 Persons setter 中加注 PropertyChanged。目前，每次调用 SearchPerson() 时 ObservableCollection 都会被替换，但由于您没有引发 PropertyChanged，WPF 无法知道它已更改。

由于您每次都在替换集合，因此简单地使用 List<T> 可能更有效。 ObservableCollection<T> 仅当您要动态地成为现有集合中的 adding/removing/moving 项时才需要。

Answer 2

GazTheDestroyer+1。没有 OnPropertyChanged 的解决方案类似于：

public void SearchPerson(object obj)
{
    if(!CanSearchPerson(obj))
      return;

    Persons.Clear();
    var result = db.DadosForSearchPerson(searchPerson);
    if (result != null)
    {
        foreach (var item in result )
        {
            MessageBox.Show(item.Name + " - " + item.Email);
            // This works, but I need these 2 items added on a listview
            Persons.Add(item)
        }
    }
    else
    {
        MessageBox.Show("Noone found with that name");
    }
}

你的Xaml

<ListView ItemsSource="{Binding Persons}">
 <ListView.View>
  <GridView>
   <GridViewColumn Width="140" Header="Name" DisplayMemberBinding="{Binding Name}"  />
   <GridViewColumn Width="140" Header="Email" DisplayMemberBinding="{Binding Email}" />
   </GridView>
  </ListView.View>
 </ListView>

需要手动将 observablecollection 填充到列表视图或任何可以显示数据的元素中

Need a hand filling observablecollection into listview or any element that can show data

wpf

xaml

listview

observablecollection

viewmodel