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我正在创建一个 WPF 应用程序，该应用程序允许用户输入有关其员工、使用Entity Framework、CRUD 操作和 MVVM 的一些详细信息。

到目前为止，我有两个ListViews. 一个包含员工姓名列表 (listview1)，而另一个 (listview2) 列出了他们的详细信息，例如出生日期、地址等。下面的图片将让您更好地了解我正在创建的内容；

列表显示

当您从 listbox1 中选择特定名称时，我正在使用 aCollectionViewSoruce来过滤 listview2 上的结果。到目前为止，我能够做到这一点，但是当我添加或删除员工时，它会引发异常；

 An unhandled exception of type 'System.StackOverflowException' occurred in *.UI.exe

以下是可能有帮助的代码片段

视图模型：

    private EmployeeListViewModel()
        : base("")
    {
        EmployeeList = new ObservableCollection<EmployeeViewModel>(GetEmployees());
        this._employeeCol = new ListCollectionView(this.employeeList); 
    }

    private ListCollectionView _employeeCol;
    public ICollectionView EmployeeCollection
    {
        get { return this._employeeCol; }
    }

    private ObservableCollection<EmployeeViewModel> employeeList;
    public ObservableCollection<EmployeeViewModel> EmployeeList
    {
        get { return employeeList; }
        set
        {
            employeeList = value;
            OnPropertyChanged("EmployeeList");
        }
    }

    private EmployeeViewModel selectedEmployee = null;
    public EmployeeViewModel SelectedEmployee
    {
        get
        {
            return selectedEmployee;
        }
        set
        {
            selectedEmployee = value;
            OnPropertyChanged("SelectedEmployee");
            EmployeeCollection.Filter = new Predicate<object>(o => SelectedEmployee != null && o != null && ((EmployeeViewModel)o).EmployeeID == SelectedEmployee.EmployeeID);
        }
    }

    internal ObservableCollection<EmployeeViewModel> GetEmployees()
    {
        if (employeeList == null)
            employeeList = new ObservableCollection<EmployeeViewModel>();
        employeeList.Clear();

        foreach (DataObjects.Employee i in new EmployeeRepository().GetAllEmployees())
        {
            EmployeeViewModel c = new EmployeeViewModel(i);
            employeeList.Add(c);
        }
        return employeeList;
    }

ListView2 - 员工列表视图；

            <ListView Name="lsvEmpoyeeList" Height="170" Width="700"
                  ScrollViewer.VerticalScrollBarVisibility="Visible" 
                  ScrollViewer.HorizontalScrollBarVisibility="Visible" 
                  HorizontalAlignment="Center"
                  IsSynchronizedWithCurrentItem="True"
                  ItemsSource="{Binding EmployeeCollection}"
                  SelectedItem="{Binding SelectedEmployee}">
                    <ListView.View>
                      <GridView>
                        <GridViewColumn Header="Position" DisplayMemberBinding="{Binding Position}" Width="100" />
                        <GridViewColumn Header="DateOfBirth" DisplayMemberBinding="{Binding DateOfBirth, StringFormat={}\{0:dd/MM/yyyy\}}" Width="100" />
                     </GridView>
                    </ListView.View>
                </ListView>

ListView1 - EmployeeSetUpView；

            <ListView Height="380" HorizontalAlignment="Left" Name="lsNames" VerticalAlignment="Top" Width="170" 
             ScrollViewer.VerticalScrollBarVisibility="Visible" 
             ScrollViewer.HorizontalScrollBarVisibility="Visible" 
             SelectedItem="{Binding SelectedEmployee}" 
             ItemsSource="{Binding EmployeeList}" Grid.RowSpan="2" Grid.Row="1">

        <ListView.View>
            <GridView>
                <GridViewColumn Header="FirstName" DisplayMemberBinding="{Binding FirstName}" Width="80" />
                <GridViewColumn Header="Surname" DisplayMemberBinding="{Binding Surname}" Width="80" />
            </GridView>
        </ListView.View>
    </ListView>
   <ContentControl Grid.Column="1" Grid.Row="1" HorizontalAlignment="Center"
                    Content="{Binding}" ContentTemplate="{StaticResource EmployeeListView}" />

如您所见，我已将过滤器放在setaccessor. 我将它放在构造函数中，但似乎发生的情况是 ListView2 上没有出现任何细节。

此外，如果我从 listview2 而不是从 listview1 中选择一行，它也会产生StackOverFlowException我不确定为什么的。

任何帮助将不胜感激或建议。另外，很抱歉这个大问题！

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1 回答 1

3

我不认为 UI 知道这EmployeeCollection已经改变了

应用过滤器后，尝试在setter 中添加PropertyChanged事件。EmployeeCollectionSelectedEmployee

public EmployeeViewModel SelectedEmployee
{
    get { return selectedEmployee;}
    set
    {
        selectedEmployee = value;
        OnPropertyChanged("SelectedEmployee");
        EmployeeCollection.Filter = new Predicate<object>(o => SelectedEmployee != null && o != null && ((EmployeeViewModel)o).EmployeeID == SelectedEmployee.EmployeeID);

        // EmployeeCollection view has changed, Notify UI
        OnPropertyChanged("EmployeeCollection");
    }
}

至于StackOverflowException我认为这是因为两者ListView都有一个TwoWay绑定SelectedEmployee，所以当一个 ListView1 更改 SelectedItem 时，它会导致 ListView2 更新其选定的项目，该项目更新 ListView1 等等，依此类推。

SelectedEmployee尝试在 ListView2 上将绑定设置为 OneWay

SelectedItem="{绑定 SelectedEmployee, Mode=OneWay}">

于 2013-03-11T10:21:01.870 回答