从Controller到View的成功消息

Question

目标

我想在添加一些用户时在我的视图中显示一些消息.

问题

当我们的模型出现问题时,有一个方法(ModelState.AddModelError)来处理不成功的消息.但是,当事情顺利的时候,我们怎样才能向用户说出他的行动是否成功？

我发现这个线程提供了解决方案,但大约三年过去了,我需要知道:没有其他方式,也许更成熟？不是这不是,但我们仍然以同样的方式处理成功的信息？

Answer 1

从Brad Christie的 答案扩展而来,我创建了一个NuGet包,BootstrapNotifications,它将通过内置的Bootstrap3支持为您完成.此软件包还支持多种通知类型(错误,警告,成功和信息),并具有预先设置的警报,并且可以轻松扩展.

该扩展支持每个相同类型和不同类型的请求的多个通知.

代码

NotificationExtensions.cs:

public static class NotificationExtensions
{
    private static IDictionary<String, String> NotificationKey = new Dictionary<String, String>
    {
        { "Error",      "App.Notifications.Error" }, 
        { "Warning",    "App.Notifications.Warning" },
        { "Success",    "App.Notifications.Success" },
        { "Info",       "App.Notifications.Info" }
    };


    public static void AddNotification(this ControllerBase controller, String message, String notificationType)
    {
        string NotificationKey = getNotificationKeyByType(notificationType);
        ICollection<String> messages = controller.TempData[NotificationKey] as ICollection<String>;

        if (messages == null)
        {
            controller.TempData[NotificationKey] = (messages = new HashSet<String>());
        }

        messages.Add(message);
    }

    public static IEnumerable<String> GetNotifications(this HtmlHelper htmlHelper, String notificationType)
    {
        string NotificationKey = getNotificationKeyByType(notificationType);
        return htmlHelper.ViewContext.Controller.TempData[NotificationKey] as ICollection<String> ?? null;
    }

    private static string getNotificationKeyByType(string notificationType)
    {
        try
        {
            return NotificationKey[notificationType];
        }
        catch (IndexOutOfRangeException e)
        {
            ArgumentException exception = new ArgumentException("Key is invalid", "notificationType", e);
            throw exception;
        }
    }
}

public static class NotificationType
{
    public const string ERROR = "Error";
    public const string WARNING = "Warning";
    public const string SUCCESS = "Success";
    public const string INFO = "Info";

}

_Notifications.cshtml:

@using YourApp.Extensions
@{
    var errorList = Html.GetNotifications(NotificationType.ERROR);
    var warningList = Html.GetNotifications(NotificationType.WARNING);
    var successList = Html.GetNotifications(NotificationType.SUCCESS);
    var infoList = Html.GetNotifications(NotificationType.INFO);
}
<!-- display errors -->
@if (errorList != null)
{
    <div class="alert alert-danger alert-dismissable">
        <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
        @if(errorList.Count() > 1){
            <strong><span class="glyphicon glyphicon-remove"></span> There are @errorList.Count() errors: </strong>
            <ul>
                @foreach (String message in errorList)
                {
                    <li>@Html.Raw(message)</li>
                }
            </ul>
        }
        else{
            <strong><span class="glyphicon glyphicon-remove"></span> Error: </strong>
            @Html.Raw(errorList.First())
        }
    </div>
}

<!-- display warnings -->
@if (warningList != null)
{
    <div class="alert alert-warning alert-dismissable">
        <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
        @if(warningList.Count() > 1){
            <strong><span class="glyphicon glyphicon-warning-sign"></span> There are @warningList.Count() warnings: </strong>
            <ul>
                @foreach (String message in warningList)
                {
                    <li>@Html.Raw(message)</li>
                }
            </ul>
        }
        else{
            <strong><span class="glyphicon glyphicon-warning-sign"></span> Warning: </strong>
            @Html.Raw(warningList.First())
        }
    </div>
}

<!-- display success -->
@if (successList != null)
{
    <div class="alert alert-success alert-dismissable">
        <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
        @if(successList.Count() > 1){
            <strong><span class="glyphicon glyphicon-ok"></span> There are @successList.Count() successful notifications: </strong>
            <ul>
                @foreach (String message in successList)
                {
                    <li>@Html.Raw(message)</li>
                }
            </ul>
        }
        else{
            <strong><span class="glyphicon glyphicon-ok"></span> Success! </strong>
            @Html.Raw(successList.First())
        }
    </div>
}

<!-- display success -->
@if (infoList != null)
{
    <div class="alert alert-info alert-dismissable">
        <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
        @if(infoList.Count() > 1){
            <strong><span class="glyphicon glyphicon-info-sign"></span> There are @infoList.Count() notifications: </strong>
            <ul>
                @foreach (String message in infoList)
                {
                    <li>@Html.Raw(message)</li>
                }
            </ul>
        }
        else{
            <strong><span class="glyphicon glyphicon-info-sign"></span> </strong>
            @Html.Raw(infoList.First())
        }
    </div>
}

要查看所有这些代码及其使用方法,您可以从github下载完整的工作演示.

Answer 2

TempData为了通知用户,将一次性交给UI并不是一种坏方法.关于他们的重要部分是他们在行动呼叫之间坚持,但一旦被阅读就被删除.因此,在仅仅传递"工作"消息的情况下,它的效果很好.

您可以通过多种方式绑定它们,但我会给您一个通用示例来帮助您:

public static class NotificationExtensions
{
    private const String NotificationsKey = "MyApp.Notifications";

    public static void AddNotification(this ControllerBase controller, String message)
    {
        ICollection<String> messages = controller.TempData[NotificationsKey] as ICollection<String>;
        if (messages == null)
        {
            controller.TempData[NotificationsKey] = (messages = new HashSet<String>());
        }
        messages.Add(message);
    }

    public static IEnumerable<String> GetNotifications(this HtmlHelper htmlHelper)
    {
        return htmlHelper.ViewContext.Controller.TempData[NotificationsKey] as ICollection<String> ?? new HashSet<String>();
    }
}

现在,在您的操作中,您可以调用this.AddNotification("User successfully added!");并在视图中使用以下内容显示它们:

@foreach (String notification in Html.GetNotifications())
{
    <div class="notification">
        <p>@notification/p>
        <i class="icon-close"></i>
    </div>
}

(......或类似的东西),可以有效地放在主视图中,并用作执行任何操作的一般通知方法.(几乎就像StackOverflow在某些事件期间页面顶部有金条一样).

Answer 3

有几种方法可以给这只猫上皮.您可以使用ViewBag:

ViewBag.SuccessMessage = "<p>Success!</p>";

然后在您的视图中,您可以将其呈现到页面:

@ViewBag.SuccessMessage

我不是ViewBag的粉丝,所以我通常会创建一个ViewModel对象,它包含我需要的特定视图所需的所有数据.成功的消息就是那种数据:

public MyViewModel{
    public bool IsSuccess {get;set;}
}

然后在您的控制器中,您将此ViewModel传递给您的stongly类型视图

[HttpPost]
public ActionResult Update(MyViewModel vm){
    //Glorious code!

   return View(vm)
}

最后,只需在您的视图中检查它并在成功时打印一条消息:

@if(vm.IsSuccess){
     <p>Here is an amazing success message!</p>
}

另外,您可以使用TempData,它可以像ViewBag一样工作,但只会持续到下一个请求结束,然后被丢弃:

TempData["SuccessMessage"] = "Success!";

Answer 4

一个很好的解决方案是集合TempData。它的值在请求结束时被清除，这使得它非常适合一次性消息，例如通知用户某件事已成功。

控制器

TempData["Message"] = "Operation successful!";

看法

@TempData["Message"]

是的，这仍然是目前最好的方法。