Question

我正在研究UserViewModel，我想知道在VM中进行微小计算是否合适，或者我是否需要将其进一步分离并在其他地方进行计算。

Public Class UserViewModel
    Public Property UserName As String
    Public Property Email As String
    Public Property Website As String
    Public Property ID As Integer
    Public Property OpenIds As List(Of OpenID)
    Public Property UserAge As String
    Public Property About As String
    Public Property Slug As String
    Public Property LastSeen As String
    Public Property Region As String
    Public Property MemberSince As String
    Public Property Reputation As String
    Public Property isUserMatch As Boolean = False
    Private MarkDownSharp As MarkdownSharp.Markdown

    Public Sub New(ByVal user As User)
        Dim currentuser As Authentication.AuthUserData = Authentication.CustomAuthentication.RetrieveAuthUser
        MarkDownSharp = New MarkdownSharp.Markdown
        With MarkDownSharp
            .AutoHyperlink = False
            .AutoNewLines = True
            .EncodeProblemUrlCharacters = True
            .LinkEmails = True
            .StrictBoldItalic = True
        End With

        _UserName = If(Not user.UserName Is Nothing, user.UserName, "User" & user.ID.ToString)
        _Email = user.Email
        _Website = user.WebSite
        _ID = user.ID
        _OpenIds = user.OpenIDs.ToList
        ''# Converts the users birthdate to an age representation
        ''#      IE: 29
        _UserAge = user.BirthDate.ToAge

        ''# Because some people can be real ass holes and try to submit bad
        ''# data (scripts and shitè) we have to modify the "About" content in
        ''# order to sanitize it.  At the same time, we transform the Markdown
        ''# into valid HTML. The raw input is stored without sanitization in
        ''# the database.  this could mean Javascript injection, etc, so the
        ''# output ALWAYS needs to be sanitized.
        _About = Trim(Utilities.HtmlSanitizer.Sanitize(MarkDownSharp.Transform(user.About)))

        ''# Removes spaces from Usernames in order to properly display the
        ''# username in the address bar
        _Slug = Replace(user.UserName, " ", "-")

        ''# Returns a boolean result if the current logged in user matches the
        ''# details view of the user in question.  This is done so that we can
        ''# show the edit button to logged in users.
        _isUserMatch = If(currentuser.ID = user.ID, True, False)


        ''# Grabs the users registration data and formats it to a time span
        ''# The "timeago-nosuffix" CssClass is there to remove the "ago"
        ''# suffix from the "member for" string. Cuz when you think about
        ''# it... "Member for 5 days ago" just sounds stupid.
        _MemberSince = user.MemberSince.ToTimeSpan("timeago-nosuffix")

        ''# Grabs the users last activity and formats it to a time span
        _LastSeen = user.ActivityLogs.Reverse.FirstOrDefault.ActivityDate.ToTimeSpan("timeago", "ago")

        ''# Formats the users reputation to a comma Deliminated number 
        ''#    IE: 19,000 or 123k
        _Reputation = user.Reputation.ToShortHandNumber


        ''# Get the name of the users current Region.
        _Region = user.Region.Region.FirstOrDefault
    End Sub

End Class

Answer 1

如果这些计算涉及给定视图的格式，那么它就是确切的位置。看起来你正在这样做：格式化视图哪个好（抱歉，如果我错过了什么，我的VB.NET代码阅读技巧开始让我逃避:-)）。另一方面，如果它是一些域逻辑，它可能更适合模型，以便可以重复使用。

Answer 2

虽然我不同意Darin，但还有另一种方法。

您可以将逻辑放在用于将域模型对象转换为dto或viewmodel对象的任何层中，而不是将简单逻辑放入ViewModel中。让我们称之为您的Mapping层。这使得您的视图模型非常愚蠢和灵活，同时将所有自定义视图转换逻辑保存在一个单独的位置。

使用AutoMapper等工具可以很容易地做到这一点。

ASP.NET MVC - ViewModel是否适合进行小型计算？

2 个答案: