Question

我的代码中有一个Player类，我想通过将对象的名称创建为Player_1，Player_2 ...来初始化其对象。我只想在运行时在字符串变量“ Object_name”中生成对象名称，并且Object_name的值应类似于Player_1，Player_2，Player_3 ...

Private Function SaveTo_Player_Class_Object(ds)
    For j As Integer = 0 To ds.Tables(0).Rows.Count - 1
        Dim Object_name As String = "Player_" + Convert.ToString(Player_Class.Total_Players + 1)
        Object_name = New Player_Class()
        Object_name.Name = ds.Tables(0).Rows(j)(0).ToString()
        Object_name.District_State_Nation = ds.Tables(0).Rows(j)(1).ToString()
        Object_name.Year_Of_Birth = ds.Tables(0).Rows(j)(2).ToString()
        Object_name.Weight = ds.Tables(0).Rows(j)(3).ToString()
    Next
End Function

但是我在VB编辑器中遇到错误“类型Player_Class的值不能转换为字符串”

在将As String更改为As Object

Private Function SaveTo_Player_Class_Object(ds)

    For j As Integer = 0 To ds.Tables(0).Rows.Count - 1
        Dim Object_name As Object = "Player_" + Convert.ToString(Player_Class.Total_Players + 1)
        Object_name = New Player_Class()
        Object_name.Name = ds.Tables(0).Rows(j)(0).ToString()
        Object_name.District_State_Nation = ds.Tables(0).Rows(j)(1).ToString()
        Object_name.Year_Of_Birth = ds.Tables(0).Rows(j)(2).ToString()
        Object_name.Weight = ds.Tables(0).Rows(j)(3).ToString()
    Next
End Function

在这种情况下，对象名称是Object_name，而不是Player_1

我的两个版本的代码都无法正常工作。

Answer 1

您正在将Object_name定义为String。在VB.NET（或C＃）中，将变量定义为特定类型时，该类型不能更改。在当前范围内，它必须始终为String。

因此，当您尝试将New Player_Class()分配给Object_name时，VB.NET告诉您不能将其转换为String。

我觉得您正在尝试定义名称为Player_1，Player_2，Player_3等的新变量，以便可以在代码的其他位置使用该名称

你不能那样做。

VB.NET是一种静态类型的语言。您要使用的每个变量都必须在编译时定义。您无法在运行时定义新变量。

但是，您可以使用数组，列表，字典或许多其他类型在运行时保存播放器变量。

您可以执行以下操作：

Private Function SaveTo_Player_Class_Object(ds As DataSet) As List(Of Player_Class)
    Dim players = New List(Of Player_Class)
    For j As Integer = 0 To ds.Tables(0).Rows.Count - 1
        Dim p = New Player_Class()
        p.Name = ds.Tables(0).Rows(j)(0).ToString()
        p.District_State_Nation = ds.Tables(0).Rows(j)(1).ToString()
        p.Year_Of_Birth = ds.Tables(0).Rows(j)(2).ToString()
        p.Weight = ds.Tables(0).Rows(j)(3).ToString()
        players.Add(p)
    Next
    Return players
End Function

现在您可以呼叫Dim players = SaveTo_Player_Class_Object(ds)，然后可以像players(0).Name这样访问每个玩家。

或者，您可以像这样使用Dictionary(Of String, Player_Class)：

Private Function SaveTo_Player_Class_Object(ds As DataSet) As Dictionary(Of String, Player_Class)
    Dim players = New Dictionary(Of String, Player_Class)
    For j As Integer = 0 To ds.Tables(0).Rows.Count - 1
        Dim p = New Player_Class()
        p.Name = ds.Tables(0).Rows(j)(0).ToString()
        p.District_State_Nation = ds.Tables(0).Rows(j)(1).ToString()
        p.Year_Of_Birth = ds.Tables(0).Rows(j)(2).ToString()
        p.Weight = ds.Tables(0).Rows(j)(3).ToString()
        players.Add("Player_" + Convert.ToString(Player_Class.Total_Players + 1), p)
    Next
    Return players
End Function

现在您可以呼叫Dim players = SaveTo_Player_Class_Object(ds)，然后可以像players("Player_42").Name这样访问每个玩家。

这有意义吗？

在运行时生成对象名称

1 个答案: