Question

我正在应用rowVersion列来解决并发问题。为了测试这些更改，我运行我的应用程序并打开两个不同的选项卡。在第一个选项卡上，我编辑一个字段，然后在第二个选项卡上，我编辑该字段。然后，将更改保存在第一个浏览器中，并得到DBUPdateConcurrency异常。即使我关闭另一个选项卡并仅在第一个浏览器上进行更改，它仍然会返回DBUPdateConcurrency异常。请参见下面的代码：

课程

public int CustomerID { get; set; }
public string Comment { get; set;}
[Timestamp]
public byte[] RowVersion { get; set; }

控制器

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit(CustomerDetail model)
{
    if (ModelState.IsValid)
    {
        int customerID = model.CustomerID;
        string comment = model.Comment;
        byte[] rowVersion = model.RowVersion;

        using (BusinessLogicLayer BLL = new BusinessLogicLayer())
        {
            try
            {
                Customer customer = 
                BLL.GetSingleCustomer(customerID);


                BLL.customerDB_entity.Entry(customer)
                    .OriginalValues["RowVersion"] = rowVersion;

                BLL.UpdateCustomer(customerID);

                BLL.SaveChanges();

            }
            catch (DbUpdateConcurrencyException ex)
            {

                var entry = ex.Entries.Single();
                var databaseEntry = entry.GetDatabaseValues();
                if (databaseEntry == null)
                {
                    ModelState.AddModelError(
                        string.Empty, 
                        "Unable to save changes. The field was deleted by another user.");

                }
                else
                {
                    ModelState.AddModelError(
                        string.Empty, 
                        "Unable to save changes. The field was updated by another user.");
                }
            }
            return RedirectToAction("Edit", new { customerID });
        }
    }
    return View(ViewModelManager.createEditViewModel(model.CustomerID));
}

此外，我在视图中为行版本添加了隐藏字段：

@Html.HiddenFor(model => Model.RowVersion)

处理乐观并发

0 个答案: