c# - 将 DatagridComboboxColumn 绑定(bind)到集合

Question

我有这个 XAML

<DataGrid ItemsSource="{Binding Users}"
          CanUserAddRows="False"
          SelectedItem="{Binding SelectedUser}"
          AutoGenerateColumns="False"
          Grid.Column="0">
    <DataGrid.Columns>
        <DataGridTextColumn Header="First name" Binding ="{Binding FirstName}"/>
        <DataGridTextColumn Header="Last name" Binding ="{Binding LastName}"/>
        <DataGridComboBoxColumn Width="*" Header="Catégorie" 
            SelectedItemBinding="{Binding Role}">
            <DataGridComboBoxColumn.ElementStyle>
                <Style>
                     <Setter Property="ComboBox.ItemsSource"
                             Value="{Binding Path=DataContext.ComboBox_Roles, 
                             RelativeSource={RelativeSource 
                             FindAncestor, AncestorType={x:Type UserControl}}}" />
                </Style>
                </DataGridComboBoxColumn.ElementStyle>
                    <DataGridComboBoxColumn.EditingElementStyle>
                        <Style>
                            <Setter Property="ComboBox.ItemsSource" Value="{Binding 
                             Path=DataContext.ComboBox_Roles, RelativeSource={RelativeSource 
                             FindAncestor, AncestorType={x:Type UserControl}}}" />
                        </Style>
                    </DataGridComboBoxColumn.EditingElementStyle>
                </DataGridComboBoxColumn>             
    </DataGrid.Columns>
</DataGrid>

我希望组合框绑定(bind)到我的角色集合
我的模型

public class User
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Role { get; set; }
}

在我的 View 模型中:

public ManageUsersViewModel()
{
    _users = new ObservableCollection<User>
    {
        new User { FirstName = "First1", LastName = "Last1", Role = "Admin" },
        new User { FirstName = "Last2", LastName = "Last2", Role ="User" },
    };

    ComboBox_Roles = new ObservableCollection<string> { "ABC", "BCD", "ASDSAD" };
}

public ObservableCollection<User> Users
{
    get => _users;
    set
    {
        _users = value;
    }
}

public ObservableCollection<string> ComboBox_Roles { get; set; }

我怎样才能绑定(bind)这些元素？似乎问题是我不能以这种方式绑定(bind)到集合中的集合。我想要实现的是我有一个带有角色列表的组合框，我可以通过选择组合框的值之一来更改我的用户角色。 Upd:更新代码，因为我意识到我在做。

Answer 1

以下代码演示了一种绑定(bind) DataGridComboBoxColumn 的可能方法

<DataGrid ItemsSource="{Binding Users}" SelectedItem="{Binding SelectedUser}" AutoGenerateColumns="False">
   <DataGrid.Columns>
      <DataGridTextColumn Header="First name" Binding ="{Binding FirstName}"/>
      <DataGridTextColumn Header="Last name" Binding ="{Binding LastName}"/>
      <DataGridComboBoxColumn Width="*" Header="Catégorie" SelectedItemBinding="{Binding Role}">
         <DataGridComboBoxColumn.ElementStyle>
            <Style>
               <Setter Property="ComboBox.ItemsSource"
                        Value="{Binding Path=DataContext.ComboBox_Roles, 
                        RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}}" />
            </Style>
         </DataGridComboBoxColumn.ElementStyle>
         <DataGridComboBoxColumn.EditingElementStyle>
            <Style>
               <Setter Property="ComboBox.ItemsSource" 
                        Value="{Binding Path=DataContext.ComboBox_Roles, 
                        RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}}" />
            </Style>
         </DataGridComboBoxColumn.EditingElementStyle>
      </DataGridComboBoxColumn>
   </DataGrid.Columns>
</DataGrid>

和 ViewModel

public class User {
   public string FirstName { get; set; }
   public string LastName { get; set; }
   public string Role { get; set; }
}
public class ManageUsersViewModel {
   public ManageUsersViewModel() {
      Users = new ObservableCollection<User>      {
                  new User { FirstName = "First1", LastName = "Last1", Role = "Admin" },
                  new User { FirstName = "Last2", LastName = "Last2", Role ="User" }};
      ComboBox_Roles = new ObservableCollection<string> { "Admin", "User", "Other" };
   }
   public ObservableCollection<User> Users { get; set; }
   public ObservableCollection<string> ComboBox_Roles { get; set; }
}

一个测试项目: https://github.com/Drreamer/GridComboBox