项目主题：我有一个MS Access 2003 adp VBA项目，它可以连接到SQL Server数据库，现在我正在将该项目转换为C# WPF，并且我要将数据直接从C# WPF中的DataGrid保存到SQL Server数据库中
详情：我有一个DataGrid，ItemsSource绑定到一个名为'ObservableCollection'的：“INVO_DATA_RASID_KHARID”和“DataGridComboBoxColumn”命名为：'ANBAR_COLUMN'此'DataGridComboBoxColumn'的'ItemSource'通过SQL Server填充。

我希望此“DataGridComboBoxColumn”以默认值显示，以便用户知道不需要从“DataGridComboBoxColumn”列表中手动选择它。
我通过这个方法中的一个静态变量设置了这个默认值，这个变量名为：'FillALLComboboxes'。
enter image description here

问题：考虑到DataGrid中的'DataGridComboBoxColumn'、'ANBAR_COL'、'DataGridComboBoxColumn'有一个默认值，用户不需要从'DataGridComboBoxColumn'列表中手动选择该项，但只要双击'ANBAR_COL'组合框单元格，默认值就会出现！关键是，为“DataGridComboBoxColumn”设置的默认值在用户进入单元格之前不会显示！enter image description here

XAML：

<DataGrid   x:Name="INVO_LST_RASID_SUB"
                        EnableColumnVirtualization="True"
                        EnableRowVirtualization="True"
                        VirtualizingPanel.IsVirtualizing="True"
                        VirtualizingPanel.VirtualizationMode="Recycling"
                        ScrollViewer.CanContentScroll="False"
                    
                        KeyboardNavigation.TabNavigation="Contained"
                        ItemsSource="{Binding INVO_DATA_RASID_KHARID}"
                        Grid.Row="5"
                        Margin="5,10"
                        AutoGenerateColumns="False"  FlowDirection="RightToLeft"  SelectionUnit="FullRow"   BorderThickness="1" >
       
            <DataGrid.Columns>

                <DataGridComboBoxColumn x:Name="ANBAR_COLUMN" MinWidth="80" Width="auto" Header=" انبار " 
                                        SelectedValueBinding="{Binding ANBAR,UpdateSourceTrigger=PropertyChanged}"
                                        DisplayMemberPath="NAMES" SelectedValuePath="CODE">
                    <DataGridComboBoxColumn.EditingElementStyle>
                        <Style TargetType="{x:Type ComboBox}">
                            <Setter Property="IsEditable" Value="True"/>
                        </Style>
                    </DataGridComboBoxColumn.EditingElementStyle>

                </DataGridComboBoxColumn>
       
            </DataGrid.Columns>
        </DataGrid>

我的窗口背后的代码（C#）：

//MainWindow:
    public partial class HEAD_LST_RASID : Window
    {
        public ObservableCollection<INVO_LST_RASID_KHARID_CSHARP> INVO_DATA_RASID_KHARID { get; set; } = new ObservableCollection<INVO_LST_RASID_KHARID_CSHARP>();

        public HEAD_LST_RASID()
        {
            InitializeComponent();
            this.DataContext = this;
        }
        public void FillALLComboboxes()
        {
            string RowSource_ANBAR = "SELECT    CODE, NAMES FROM  dbo.TCOD_ANBAR";
            //Search for the default value if it exists
            var rst = dbms.Database.SqlQuery<int?>("SELECT     ANBCO FROM dbo.OPANBACCESS WHERE     (USERCO = " + Baseknow.USERCOD + " ) ORDER BY dbo.OPANBACCESS.RDF").ToList();
            if (rst.Count > 0)
            {
                Baseknow.anbardef = (int)rst.FirstOrDefault();
            }
            var ARST = dbms.Database.SqlQuery<Custom_TCODANBAR>(RowSource_ANBAR).ToList();
            ANBAR_COLUMN.ItemsSource = ARST;
        }
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            FillALLComboboxes();
            
              var QRE_LST = dbms.Database.SqlQuery<INVO_LST_RASID_KHARID_CSHARP>($@"SELECT * FROM INVOICES").ToList();
              INVO_DATA_RASID_KHARID?.Clear();
              
                foreach (var item in QRE_LST)
                    INVO_DATA_RASID_KHARID.Add(item);
        }
    }

型号类别：

//Model:
    public class CTABLES
    {
        public class INVO_LST_RASID_KHARID_CSHARP : INotifyPropertyChanged, ICloneable
        {
            public object Clone()
            {
                return this.MemberwiseClone();
            }
        
            public INVO_LST_RASID_KHARID_CSHARP()
            {
                ANBAR = Baseknow.anbardef;
            }

            private int? _anbar;
            public int? ANBAR
            {
                get
                {
                    return _anbar;
                }
                set
                {
                    if (_anbar == value)
                        return;
                    _anbar = value;
                    OnPropertyChanged("ANBAR");
                }
            }

            public event PropertyChangedEventHandler PropertyChanged;
            protected virtual void OnPropertyChanged(string propertyName = "")
            {
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }

我想要的是在加载'DataGrid'数据时显示'DataGrid'内的此组合框已选择默认值（无需双击并进入CellEditing模式）。