WPF C# - 在 DataGridComboBoxColumn 控件中选择选项的问题

Question

我这几天一直在学习 WPF 技术。我在处理 DataGridComboBoxColumn 控件时遇到问题。一切正常，但是从选择列表中选择一个选项并移动到另一行后，选择值的单元格有一个红色边框，整个控件锁定，没有进一步交互的可能性。 请帮忙。

<DataGridComboBoxColumn x:Name="colCategory"
                                        Header="Category" 
                                        IsReadOnly="False"
                                        Width="Auto" 
                                        MinWidth="150" 
                                        SelectedValueBinding="{Binding Category}" SelectedValuePath="Key"
                                        SelectedItemBinding="{Binding Category}" DisplayMemberPath="Key"
                                     >

还有我的伪代码：

public class PairCategory
{
    public String Key { get; set; }
    public long ? Id { get; set; }
}

public class CategoryDescription : ObservableBase { public PairCategory Category { get => category; set => category = value; } }  

((DataGridComboBoxColumn)colCB.colObj).ItemsSource = new ObservableCollection<PairCategory>(){ new PairCategory(..), .., PairCategory(..) }; this.controlDataGrid.ItemsSource = lstCategory;

Answer 1

我也遇到了数据网格中的组合框的问题。可能为绑定而锁定。我对组合框使用了以下方法

public void TestScenario()
{
     var exampleDataList = new List<ExampleData>();

     exampleDataList.Add(new ExampleData("UK"));
     exampleDataList.Add(new ExampleData("USA"));
     exampleDataList.Add(new ExampleData("France"));
     ExampleDataGrid.ItemsSource = exampleDataList;
}




public class ExampleData : INotifyPropertyChanged
{
   public event PropertyChangedEventHandler PropertyChanged;

   public ObservableCollection<string> countries { get; set; }
   public ObservableCollection<string> cities { get; set; }

   private string country;
   private string city;

   public string Country
   {
       get
       {
          return country;
       }
       set
       {
           country = value;
           // Call OnPropertyChanged whenever the property is updated
           OnPropertyChanged("Country");
       }
  }
  public string City
  {
      get
      {
          return city;
      }
      set
      {
          city = value;
      }
  }
      

  public ExampleData(string country)
  {
     this.country = country;
     countries = new ObservableCollection<string>() { "UK", "USA", "France" };
     cities = new ObservableCollection<string>() { "London", "Bristol", "Plymouth" };
  }

  // Create the OnPropertyChanged method to raise the event 
  protected void OnPropertyChanged(string name)
  {
      UpdateOptions();

     PropertyChangedEventHandler handler = PropertyChanged;
     if (handler != null)
     {
          handler(this, new PropertyChangedEventArgs(name));

     }
  }

  public void UpdateOptions()
  {
      List<string> oldCities = cities.ToList<string>();
      List<string> newCities;

      foreach (string city in oldCities)
      {
          cities.Remove(city);
      }

      if (country == "UK")
      {
           newCities = new List<string>() { "London", "Bristol", "Birmingham" };
      }
      else if (country == "USA")
      {
           newCities = new List<string>() { "New York", "LA", "Texas" };
      }
      else if (country == "France")
      {
           newCities = new List<string>() { "Paris", "Lyon", "Nice" };
      }
      else
      {
          newCities = new List<string>();
      }

      foreach (string city in newCities)
      {
          cities.Add(city);
      }
   }
}

xml 代码

   <DataGrid
    Name="ExampleDataGrid"
    AutoGenerateColumns="False"
    >
            <DataGrid.Columns>

                <DataGridTemplateColumn Header="Country">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <ComboBox ItemsSource="{Binding countries}" SelectedItem="{Binding Country, UpdateSourceTrigger=PropertyChanged}"/>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>

                <DataGridTemplateColumn Header="city">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <ComboBox ItemsSource="{Binding cities}" SelectedItem="{Binding City, UpdateSourceTrigger=PropertyChanged}"/>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>

            </DataGrid.Columns>
        </DataGrid>