WPF实现DataGrid自动生成关联数据的ComboBox列

我的应用中存在带关联表的数据源，例如产品表仅存储产品类型ID、人员表存储性别类型ID。我希望通过通用DataGrid自动生成列来展示不同表的数据，简单类型（如String、int）已正常显示，但关联数据无法自动生成可选择的ComboBox列。

以下是我尝试的代码：

XAML代码 #

<Grid>
    <DataGrid x:Name="T_DataGrid"
              AutoGenerateColumns="True"
              EnableRowVirtualization="True"
              ItemsSource="{Binding DataCollection}"
              Margin="10,10,10,8"
              RowDetailsVisibilityMode="VisibleWhenSelected"
              Grid.Row="1">
    </DataGrid>
</Grid>

PersonModel #

public class PersonModel
{
    public PersonModel(int genderType)
    {
        _GenderType = genderType;
    }

    public int Age { get; set; }

    public String Name { get; set; }

    private static int _GenderType { get; set; }

    public GenderModel GenderType { get; set; }
}

GenderModel #

public class GenderModel
{
    public GenderModel() { }

    public int Type { get; set; }
    public string Description { get; set; }

    public override string ToString()
    {
        return $"{Type} -> {Description}";
    }
}

PersonViewModel（窗口DataContext） #

public PersonViewModel()
{
    _genderList.Add(new GenderModel { Type = 1, Description = "Male" });
    _genderList.Add(new GenderModel { Type = 2, Description = "FeMale" });
    _genderList.Add(new GenderModel { Type = 3, Description = "What Ever You Want For My Own Peace" });

    DataCollection.Add(new PersonModel(1) { Age = 20,  Name = "Peter" });
    DataCollection.Add(new PersonModel(2) { Age = 22,  Name = "Lydia" });
    DataCollection.Add(new PersonModel(3) { Age = 30,  Name = "It is not your business because i'm not female or male" });

    foreach (var person in _dataCollection)
    {
        person.GenderType = _genderList.FirstOrDefault();
    }
}

private ObservableCollection<PersonModel> _dataCollection = new ObservableCollection<PersonModel>();

public ObservableCollection<PersonModel> DataCollection
{
    get { return _dataCollection; }
    set => SetProperty(ref _dataCollection, value);
}

private List<GenderModel> _genderList = new List<GenderModel>();

实现方案 #

WPF DataGrid默认自动生成列时，只会为简单值类型生成常规列，不会自动识别关联对象并生成ComboBox列。要实现这个需求，需要通过AutoGeneratingColumn事件拦截列生成过程，手动替换为ComboBox列：

1. 修改ViewModel，公开性别列表
   在PersonViewModel中添加公开的性别列表属性，供XAML绑定下拉选项：

   public List<GenderModel> GenderList => _genderList;
   

2. 给DataGrid添加AutoGeneratingColumn事件
   修改XAML中的DataGrid，添加事件绑定：

   <DataGrid x:Name="T_DataGrid"
             AutoGenerateColumns="True"
             EnableRowVirtualization="True"
             ItemsSource="{Binding DataCollection}"
             Margin="10,10,10,8"
             RowDetailsVisibilityMode="VisibleWhenSelected"
             Grid.Row="1"
             AutoGeneratingColumn="T_DataGrid_AutoGeneratingColumn">
   </DataGrid>
   

3. 实现事件处理逻辑
   在窗口后台代码中添加事件处理方法，判断属性类型并生成ComboBox列：

   private void T_DataGrid_AutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e)
   {
       // 拦截GenderModel类型的列生成
       if (e.PropertyType == typeof(GenderModel))
       {
           // 取消默认生成的列
           e.Cancel = true;
   
           // 创建ComboBox列
           var comboBoxColumn = new DataGridComboBoxColumn
           {
               Header = e.Column.Header,
               // 绑定当前行数据的GenderType属性
               SelectedItemBinding = new Binding(e.PropertyName),
               // 绑定下拉选项到ViewModel的GenderList
               ItemsSource = ((PersonViewModel)DataContext).GenderList,
               // 设置下拉列表显示的字段
               DisplayMemberPath = "Description"
           };
   
           // 将自定义列添加到DataGrid
           ((DataGrid)sender).Columns.Add(comboBoxColumn);
       }
   }
   

4. 修正Model中的问题
   原PersonModel中的_GenderType是静态字段，会导致所有实例共享同一个值，改为实例字段：

   public class PersonModel
   {
       private int _genderType; // 去掉static，改为实例字段
       
       public PersonModel(int genderType)
       {
           _genderType = genderType;
       }
   
       public int Age { get; set; }
       public string Name { get; set; }
       public GenderModel GenderType { get; set; }
   }
   

   同时修正ViewModel中给Person赋值GenderType的逻辑，根据构造时传入的ID匹配对应的性别：

   foreach (var person in _dataCollection)
   {
       // 先给PersonModel添加公开的GenderTypeId属性
       // public int GenderTypeId { get; }
       // 再匹配对应性别
       person.GenderType = _genderList.FirstOrDefault(g => g.Type == person.GenderTypeId);
   }
   

内容的提问来源于stack exchange，提问作者brobro