<riaControls:DomainDataSource AutoLoad="True" d:DesignData="{d:DesignInstance my:z_plan_name, CreateList=true}" 
                                      Height="0" LoadedData="z_plan_nameDomainDataSource_LoadedData" 
                                      Name="z_plan_nameDomainDataSource" QueryName="GetZ_plan_nameQuery" Width="0" Margin="0,0,478,250">
            <riaControls:DomainDataSource.DomainContext>

private void DeleteItem_ItemClick(object sender, ItemClickEventArgs e)
        {
            GridCellMenuInfo menuInfo = Control_Plan.GridMenu.MenuInfo as GridCellMenuInfo;
            if (menuInfo != null && menuInfo.Row != null)
            Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);
        }

    public void DeleteZ_plan_name(z_plan_name z_plan_name)
        {
            if ((z_plan_name.EntityState == EntityState.Detached))
            {
                this.ObjectContext.z_plan_name.Attach(z_plan_name);
            }
            this.ObjectContext.z_plan_name.DeleteObject(z_plan_name);
        }

public void DeleteZ_plan_name(z_plan_name z_plan_name)
{
  z_plan_name.del = true;
}

public void DeleteZ_plan_name(z_plan_name z_plan_name)
        {
          
            if ((z_plan_name.EntityState == EntityState.Detached))
            {
                this.ObjectContext.z_plan_name.Attach(z_plan_name);
            }
            this.ObjectContext.z_plan_name.DeleteObject(z_plan_name);
        }

public void DeleteZ_plan_name(z_plan_name z_plan_name)
        {
           z_plan_name.del = true;
        }

    private void DeleteItem_ItemClick(object sender, ItemClickEventArgs e)
        {
            GridCellMenuInfo menuInfo = Control_Plan.GridMenu.MenuInfo as GridCellMenuInfo;
            if (menuInfo != null && menuInfo.Row != null)
            Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);
           //вот тут в идеале нужно добавить в базу к удаляемой строке в поле del параметр delete
        }

public void DeleteZ_plan_name(z_plan_name z_plan_name)
        {
            z_plan_name.delete = true;
        }

private void DeleteItem_ItemClick(object sender, ItemClickEventArgs e)
        {
            GridCellMenuInfo menuInfo = Control_Plan.GridMenu.MenuInfo as GridCellMenuInfo;
            if (menuInfo != null && menuInfo.Row != null)
            Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);
        }

   private void DeleteItem_ItemClick(object sender, ItemClickEventArgs e)
        {
            GridCellMenuInfo menuInfo = Control_Plan.GridMenu.MenuInfo as GridCellMenuInfo;
            if (menuInfo != null && menuInfo.Row != null)
Тут            Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);
        }

 private void DeleteItem_ItemClick(object sender, ItemClickEventArgs e)
        {
            GridCellMenuInfo menuInfo = Control_Plan.GridMenu.MenuInfo as GridCellMenuInfo;
"красная точка"            if (menuInfo != null && menuInfo.Row != null)
            Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);
        }

 private void DeleteItem_ItemClick(object sender, ItemClickEventArgs e)
        {
            GridCellMenuInfo menuInfo = Control_Plan.GridMenu.MenuInfo as GridCellMenuInfo;
            if (menuInfo != null && menuInfo.Row != null)
"красная точка"            Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);
        }

Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);

 public void DeleteZ_plan_name(z_plan_name z_plan_name)
        {
            z_plan_name.delete = "delete";
         }

<riaControls:DomainDataSource AutoLoad="True" d:DesignData="{d:DesignInstance my:z_plan_name, CreateList=true}" 
                                      Height="0" LoadedData="z_plan_nameDomainDataSource_LoadedData" 
                                      Name="z_plan_nameDomainDataSource" QueryName="GetZ_plan_nameQuery" Width="0" Margin="0,0,478,250">
            <riaControls:DomainDataSource.DomainContext>
                  <my:myContext />
            </riaControls:DomainDataSource.DomainContext>
        </riaControls:DomainDataSource>

z_plan_nameDomainDataSource.DomainContext.???

.............
 Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);

<sdk:DataGrid  Name="DataGrid_Plan"  ItemsSource="{Binding Data, ElementName=z_plan_nameDomainDataSource}" AutoGenerateColumns="True">
</sdk:DataGrid>

 z_plan_nameDomainDataSource.DataView.Remove(DataGrid_Plan.SelectedItem);
 z_plan_nameDomainDataSource.SubmitChanges();

   public void DeleteZ_plan_name(z_plan_name z_plan_name)
        {
          
           if ((z_plan_name.EntityState == EntityState.Detached))
            {
                this.ObjectContext.z_plan_name.Attach(z_plan_name);
            }
            this.ObjectContext.z_plan_name.DeleteObject(z_plan_name);
        }

z_plan_name.delete = "delete";

     public void DeleteZ_plan_name(z_plan_name z_plan_name)
        {
           if ((z_plan_name.EntityState == EntityState.Detached))
            {
                this.ObjectContext.z_plan_name.Attach(z_plan_name);
                z_plan_name.delete = "delete";
            }
            //this.ObjectContext.z_plan_name.DeleteObject(z_plan_name);
        }

   private void DeleteItem_ItemClick(object sender, ItemClickEventArgs e)
        {
            GridCellMenuInfo menuInfo = Control_Plan.GridMenu.MenuInfo as GridCellMenuInfo;
            if (menuInfo != null && menuInfo.Row != null) 
            Control_Plan.DeleteRow(menuInfo.Row.RowHandle.Value);
            z_plan_nameDomainDataSource.SubmitChanges();
        }

   public void DeleteOptions(Options options)
        {
            if ((options.EntityState == EntityState.Detached))
            {
                this.ObjectContext.Options.Attach(options);
                options.checkBox_b = true; //добавил как в предыдущем примере
            }
           // this.ObjectContext.Options.DeleteObject(options);
        }

private void checkBox_b_Click(object sender, RoutedEventArgs e)
        {
            if (checkBox_b.IsChecked.Value)
            {
        // вот тут записываем значение true
          MessageBox.Show("True");//это просто флаг
            }
            else
            {
               MessageBox.Show("False");
            }

<riaControls:DomainDataSource AutoLoad="True" d:DesignData="{d:DesignInstance my:z_options, CreateList=true}" 
                                      Height="0" LoadedData="z_options" 
                                      Name="z_optionsDomainDataSource" QueryName="GetZ_optionsQuery" Width="0" Margin="0,0,478,250"
                                      >
            <riaControls:DomainDataSource.DomainContext>
                <my:myContext />
            </riaControls:DomainDataSource.DomainContext>

    public void DeleteZ_options(z_options z_options)
        {
            if ((z_options.EntityState == EntityState.Detached))
            {
                this.ObjectContext.z_options.Attach(z_options);
            }
            this.ObjectContext.z_options.DeleteObject(z_options);
        }