db.savechanges（）行在EF中冻结

Question

当db.savechanges（）行到达断点时。什么都没发生。 catch块中没有错误。浏览器只是冻结而不保存数据。我在asp.net mvc上使用oracle。我的代码如下：

public ResponseResult AddUserPermission(USER_PERMISSION permission)
{
    try
    {

        _db.Entry(permission).State = EntityState.Modified;
        _db.SaveChanges();
        return new ResponseResult();
    }
    catch (Exception ex)
    {
        //return new ResponseResult();
        return new ResponseResult(ResutlType.Error, ex.Message);
    }


}

控制器调用方法如下：

[HttpPost]
[CustomAuthorize("Admin")]
public ActionResult Create(USER model)
{
    try
    {

        string moduleId = Request.Form["ModuleId"];
        string isSelected = Request.Form["IsSelected"];

        model.DATE_CREATED = DateTime.Now;
        model.DATE_UPDATED = DateTime.Now;
        model.STATUS = (int)Status.Active;

        var userPermission = processPermissionData(moduleId, isSelected);
        //userPermission contains a list of permissions which i am trying to save
        _userService.Add(model);

        foreach (var permission in userPermission)
        {
            _userService.AddUserPermission(permission);
        }

        return RedirectToAction("Index");
    }
    catch
    {
        return View();
    }
}

我没有得到浏览器或VS 15的响应。我得到的只是浏览器标签中的加载标志。