WPF绑定SelectedItem的嵌套属性到Combobox的双向绑定

Question

商业模式:

public class Employe : INotifyPropertyChanged
{
    public int EmployeId { get; set; }
    public string EmployeName { get; set; }
    public Department EmployeDepartment { get; set; }
}
public class Department : INotifyPropertyChanged
{
    public int DepartmentId { get; set; }
    public string DepartmentName { get; set; }
}

在 MainWindow 中的列表属性：

    public List<Department> Departments { get; set; } = new List<Department>();
    public List<Employe> Employes { get; set; } = new List<Employe>();

示例初始化：

        var office = new Department { DepartmentId = 1, DepartmentName = "Office" };
        var admin = new Department { DepartmentId = 2, DepartmentName = "Administration" };
        var purchasing = new Department { DepartmentId = 3, DepartmentName = "Purchasing" };
        Departments.Add(office);
        Departments.Add(admin);
        Departments.Add(purchasing);
        Employes.Add(new Employe { EmployeId = 1, EmployeName = "John", EmployeDepartment = office });
        Employes.Add(new Employe { EmployeId = 2, EmployeName = "Sue", EmployeDepartment = admin });
        Employes.Add(new Employe { EmployeId = 3, EmployeName = "Bill", EmployeDepartment = admin });
        Employes.Add(new Employe { EmployeId = 4, EmployeName = "Linda", EmployeDepartment = purchasing });
        Employes.Add(new Employe { EmployeId = 5, EmployeName = "Tom", EmployeDepartment = purchasing });
        Employes.Add(new Employe { EmployeId = 6, EmployeName = "Mick", EmployeDepartment = purchasing });

首先，我展示雇员列表（工作正常）。

        <ListBox x:Name="lbEmployes" ItemsSource="{Binding Employes}" DisplayMemberPath="EmployeName" />

现在，我想通过使用DataTemplate来展示所选项的详细视图：

        <ContentControl Content="{Binding ElementName=lbEmployes, Path=SelectedItem}" ContentTemplate="{StaticResource EmployesTemplate}" />

数据模板：

    <DataTemplate DataType="{x:Type local:Employe}" x:Key="EmployesTemplate">
        <StackPanel>
            <TextBlock Text="{Binding Path=EmployeId}"></TextBlock>
            <TextBox Text="{Binding Path=EmployeName}"></TextBox>
            <ComboBox ItemsSource="{Binding Path=EmployeDepartment, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" SelectedValuePath="Department" DisplayMemberPath="DepartmentName" />
        </StackPanel>
    </DataTemplate>

Id和Name可以正常工作。如何修复ComboBox？如何绑定ItemsSource和SelectedItem？

完整的源代码：https://gist.github.com/LwServices/a88818e52a612790e3785e308f5ad2ce

- LWS

---

项目源不应该是employeedepartment（单个），而应该是departments（列表），也许selecteditem应该绑定到employeedepartment？ - Kevin Cook

Answer 1

下拉框的正确绑定方法是:

            <ComboBox ItemsSource="{Binding Departments, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:MainWindow}}}" DisplayMemberPath="DepartmentName" SelectedItem="{Binding Path=EmployeDepartment}" />

- LWS