Question

我需要创建一个取消按钮，它将回滚自上次上下文保存以来的所有更改。我得到的是按钮点击后的回滚。但是，DataGridView并没有反映出这种变化。如果我退出该程序，我可以看到没有数据被更改。

我得到了以下表格（我没有在“输出”窗口中看到任何错误）但是，我读到的所有内容都表示将上下文包装在using语句中。在这种情况下，这仍然适用吗？我已经使用了Rollback并在一个保存方法中提交了try / catch但是这个平面没有看起来不对。如果我生成另一个表单，它会添加到当前事务中吗？

/// <summary>
/// </summary>
public partial class Form2 : Form
{
    /// <summary>
    /// </summary>
    private TestContext _context;

    /// <summary>
    /// </summary>
    private DbContextTransaction _transaction;

    /// <summary>
    /// </summary>
    public Form2()
    {
        InitializeComponent();
    }

    /// <summary>
    /// </summary>
    /// <param name="e"></param>
    protected override void OnClosing(CancelEventArgs e)
    {
        base.OnClosing(e);
        _transaction.Rollback();
        _context.Dispose();
    }

    /// <summary>
    /// </summary>
    /// <param name="e"></param>
    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);
        _context = new TestContext();
        _transaction = _context.Database.BeginTransaction();
        SetupDataGridView();
    }

    /// <summary>
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnCancel_Click(object sender, EventArgs e)
    {
        _transaction.Rollback();
        _context = new TestContext();
        SetupDataGridView();
        _transaction = _context.Database.BeginTransaction();
    }

    /// <summary>
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnSave_Click(object sender, EventArgs e)
    {
        Validate();
        PersonDataGridView.CommitEdit(DataGridViewDataErrorContexts.Commit);
        _context.SaveChanges();
        _transaction.Commit();
        PersonBindingSource.ResetBindings(true);
        _transaction = _context.Database.BeginTransaction();
    }

    /// <summary>
    /// </summary>
    private void SetupDataGridView()
    {
        _context.People.Load();
        ObservableCollection<Person> people = _context.People.Local;
        PersonBindingSource.DataSource = people.ToBindingList();
        PersonBindingSource.RaiseListChangedEvents = true;
        PersonDataGridView.AutoGenerateColumns = false;
        PersonDataGridView.DataSource = PersonBindingSource;
    }
}

EntityFramework 6 Transaction.Rollback和Commit

0 个答案: