TempData依赖注入

Question

我正在创建一个NotificationService以插入到我的MVC控制器中，以便在我的视图中显示烤面包消息。我最初打算将消息存储在HttpContext.Current.Items中，但有时控制器重定向到成功的另一个视图。

我认为TempData可能是第二好的。但是，我不确定如何使用依赖注入将TempData注入到NotificationService中？

用代码示例更新：

public enum NotifyType
{
    Success,
    Error,
    Warn,
    Info
}
public class NotificationMessage
{
    public NotificationMessage(NotifyType notifyType, string message)
    {
        NotifyType = notifyType;
        Message = message;
    }
    public NotifyType NotifyType { get; set; }
    public string Message { get; set; }
}
public interface INotificationService
{
    void Success(string message);
    void Error(string message);
    void Warn(string message);
    void Info(string message);
    List<NotificationMessage> GetMessages();
}
public class HttpNotificationService : INotificationService
{
    private TempDataDictionary _tempData;
    public HttpNotificationService(TempDataDictionary tempData)
    {
        _tempData = tempData;
    }

    private void SetNotification(NotificationMessage notificationMessage)
    {
        List<NotificationMessage> messages = GetMessages();
        messages.Add(notificationMessage);
        _tempData["Notifications"] = messages;
    }
    public void Success(string message)
    {
        SetNotification(new NotificationMessage(NotifyType.Success, message));
    }
    public void Error(string message)
    {
        SetNotification(new NotificationMessage(NotifyType.Error, message));
    }
    public void Warn(string message)
    {
        SetNotification(new NotificationMessage(NotifyType.Warn, message));
    }
    public void Info(string message)
    {
        SetNotification(new NotificationMessage(NotifyType.Info, message));
    }
    public List<NotificationMessage> GetMessages()
    {
        return _tempData["Notifications"] as List<NotificationMessage> ?? new List<NotificationMessage>();
    }
}
public class HomeController : Controller
{
    private INotificationService _notificationService;
    public HomeController(INotificationService notificationService)
    {
        _notificationService = notificationService;
    }
    public ActionResult Action()
    {
        // Do something
        _notificationService.Success("Hooray, you succeeded!");
        return View();
    }
}

Answer 1

对于基本需求，我将覆盖控制器中的OnActionExecuting。然后将通知放在TempData中：

protected override void OnActionExecuting(ActionExecutingContext filterContext) {
    TempData["Notifications"] = _notificationService.GetNotifications(/* current user */);
    base.OnActionExecuting(filterContext);
}

在我们的当前项目中，我们使用一个PartialView，它是通过一个特定于此目的的操作呈现的。这对复杂的设置来说更方便。但这可能就足够了，这取决于你的需求。