当SaveChanges（）不成功时，如何撤消更改？

Question

如何在SaveChanges（）不成功时撤消更改？

contextObject.Toto.AddObject( new Toto());

try
{
    contextObject.SaveChanges();
}
catch
{
      // Undo changes !
}

在这个示例中，我想删除内存中的新Toto对象。我不想手动删除它。我想将contextObject同步到我的数据库。

Answer 1

Microsoft正在努力：Unable to refresh some items in the ObjectContext

Answer 2

Saving Changes and Managing Concurrency：

try
{
    // Try to save changes, which may cause a conflict.
    int num = context.SaveChanges();
    Console.WriteLine("No conflicts. " +
        num.ToString() + " updates saved.");
}
catch (OptimisticConcurrencyException)
{
    // Resolve the concurrency conflict by refreshing the 
    // object context before re-saving changes. 
    context.Refresh(RefreshMode.ClientWins, orders);

    // Save changes.
    context.SaveChanges();
    Console.WriteLine("OptimisticConcurrencyException "
    + "handled and changes saved");
}