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我有一个Player用于创建List(Of Player). 我需要在应用程序关闭时保存它。在 Windows 窗体中，我只是序列化，但在 UWP 中不再可能，所以我不得不谷歌了几十个小时，最后我偶然发现了Microsoft.Toolkit.Uwp, then Newtonsoft.Json，但我很遗憾地无法使用它们。我需要你的帮助！

假设我有一个小班：

Dim Name As String
Dim Score As Double
Public Class Player
    <JsonConstructor()>
    Public Sub New(Name As String, Score As Double) ' New with score
        Me.Name = Name
        Me.Score = Math.Max(1, Score)
    End Sub
End Class
Public Overrides Function ToString() As String ' ToString
    Return $"{Name} [{Score}]"
End Function

如何成功读取和写入List(Of Player)?

' Loading MainPage.xaml
Private Sub MainPage_Loading() Handles Me.Loading
    ReadAsync()
    MainFrame.Margin = New Thickness(0)
    Window.Current.Content = MainFrame
    MainFrame.Navigate(GetType(PlayerList), Players)
End Sub

' Read
Private Async Sub ReadAsync()
    Players = JsonConvert.DeserializeObject(Of List(Of Player))(Await FileIO.ReadTextAsync((Await StorageFolder.CreateFileAsync("players.json", CreationCollisionOption.OpenIfExists))))
    If Players Is Nothing Then
        Players = New List(Of Player)
        WriteAsync()
    End If
End Sub

' Write
Public Shared Async Sub WriteAsync()
    Await FileIO.WriteTextAsync(Await StorageFolder.CreateFileAsync("players.json", CreationCollisionOption.ReplaceExisting), JsonConvert.SerializeObject(Players, Formatting.Indented))
End Sub

' Loading PlayerList.xaml
Protected Overrides Sub OnNavigatedTo(e As NavigationEventArgs)
    ListBoxPlayers.Items.Clear()
    Players = e.Parameter
    For Each Player In Players
        ListBoxPlayers.Items.Add(Player)
    Next
End Sub

' Adding a new player in the interface
Private Sub ButtonAddPlayer_Click(sender As Button, e As RoutedEventArgs) Handles ButtonAddPlayer.Click
    ' ...
    ' Commit
    MainPage.Players.Add(New Player(TextBoxName.Text))
    ListBoxPlayers.Items.Add(MainPage.Players(MainPage.Players.Count - 1))
    MainPage.WriteAsync()
End Sub

所以这一切都令人困惑。当我通过界面添加播放器时，它会像往常一样进入我的 ListBox。但是，当我关闭应用程序并重新打开它时，我得到了一些空对象。

不同球员名单 序列化无效！

我做了一些愤怒的测试来更多地了解我的问题，结果证明我根本没有序列化，但我可能正确反序列化。

愤怒的测试

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1 回答 1

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我找到了，原来是在我的课Player上。

我用了什么：

Dim Name As String
Dim Score As Double

什么有效：

Public Name As String
Public Score As Double

我应该做的：

Public Property Name As String
Public Property Score As Double

我被教导在用 Java 编码时永远不要将变量设置为“公共”，而且我不知道Property在 Visual Basic 中存在这种情况。

于 2017-07-29T04:52:29.733 回答