Question

我的应用程序中有DataGrid，其XML定义如下：

<DataGrid x:Name="grid"
          DockPanel.Dock="Top"
          Visibility="{Binding gridVisibility}"
          CellStyle="{StaticResource ValidationReadyCellStyle}"
          IsSynchronizedWithCurrentItem="True"
          HorizontalAlignment="Stretch"
          HorizontalContentAlignment="Stretch"
          VerticalContentAlignment="Stretch"
          ColumnWidth="*"
          ItemsSource="{Binding DBtable, ValidatesOnExceptions=False,
          NotifyOnSourceUpdated=True, TargetNullValue={x:Static system:String.Empty}, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
          AutoGenerateColumns="True" AutoGeneratingColumn="grid_OnAutoGeneratingColumn" CanUserAddRows="True"
          BeginningEdit="grid_OnBeginningEdit" PreviewKeyDown="grid_OnPreviewKeyDown" RowEditEnding="grid_OnRowEditEnding" CellEditEnding="grid_OnCellEditEnding">
          <DataGrid.RowValidationRules>
              <local:RowValidationChecker ValidationStep="UpdatedValue"/>
          </DataGrid.RowValidationRules>
</DataGrid>

可以看出，ItemsSource绑定到名为DBtable的表，具体取决于自动生成的行/列。以下是用于连接和更新数据库的代码段：

public bool SaveToDB(DataTable table, string tableName)
{
    var msSqlConnectionClass = new MsSqlConnectionClass(MsSqlLogin.Default.Server,
                                                            MsSqlLogin.Default.LoremIpsumDB, MsSqlLogin.Default.UID,
                                                            MsSqlLogin.Default.Password, MsSqlLogin.Default.WinAuth);
    SqlConnection msSqlConnection = msSqlConnectionClass.getMsSqlConnection();
    msSqlConnection.Open();
    try
    {
        string strSQL = "SELECT * FROM " + tableName;
        SqlDataAdapter da = new SqlDataAdapter(strSQL, msSqlConnection);
        SqlCommandBuilder command = new SqlCommandBuilder(da);
        da.UpdateCommand = command.GetUpdateCommand();
        da.DeleteCommand = command.GetDeleteCommand();
        da.InsertCommand = command.GetInsertCommand();
        da.Update(table);
        msSqlConnection.Close();
    }
    catch (Exception e)
    {
        ServiceLog.AddLogInfo(e.ToString());
        msSqlConnection.Close();
        return false;
    }
    return true;
}

问题是，尽管在DataGrid中完成的任何添加或编辑操作在数据库中得到了完美更新，但遗憾的是我无法为删除操作实现相同的行为。删除是在源本身完成的，所以当我在删除操作（我使用DBtable.Rows.RemoveAt()）后检查行计数时，DBtable向我显示该行已删除，但更改不是使用上面显示的SaveToDB()函数进行更新尝试后反映在数据库中。我该怎么办？

Answer 1

我发现了问题。显然

Dbtable.Rows.RemoveAt(selectedIndex);

不会让数据表知道已发出删除命令。因此，当在数据库上运行更新命令时，不会看到并执行删除。相反，使用

row = DBtable.Rows[selectedIndex];
row.Delete();

解决了这个问题。

Answer 2

类似的东西也让我很困惑。对于那些可能在以后搜索时遇到此页面的人来说，这是一个解决方案。

public DataTable GetMembers()
        {
            conn = new SqlCeConnection(@"Data Source = DataModel.sdf");
            dataAdapter = new SqlCeDataAdapter("Select * from Members", conn);
            commandBuilder = new SqlCeCommandBuilder(dataAdapter);
            dataTable = new DataTable();
            dataAdapter.Fill(dataTable);
            dataTable.RowChanged += new DataRowChangeEventHandler(dataTable_RowChanged);
            dataTable.RowDeleted += new DataRowChangeEventHandler(dataTable_RowDeleted);
            dataTable.DefaultView.ListChanged += DefaultView_ListChanged;
            return dataTable;
        }

        void DefaultView_ListChanged(object sender, System.ComponentModel.ListChangedEventArgs e)
        {
            if (e.ListChangedType == System.ComponentModel.ListChangedType.ItemDeleted)
            {
                try
                {
                    dataAdapter.Update(dataTable);
                }
                catch (Exception ex)
                {
                    System.Windows.MessageBox.Show(ex.Message);
                }
            }
        }

WPF DataGrid删除的行不会在数据库中更新（删除）

2 个答案: