vb.net - 以编程方式对成员字段进行 VB ReDim

Question

我正在尝试根据读取文件来重新调整成员数组。我不知道该怎么做。这是我尝试过的，但它不起作用。

Public Class BS
    Public A() As String
    Public B() As Double
    Public C() As Double
End Class

Public Class SB

    Public MyBS() As BS

    'ReadFieldString is a function that returns a string of the field name of Class BS,
    'i.e., A, B or C.  For test purpose, retun a constant
    Public Function ReadFieldString() As String
        Return "B"
    End Function

    'GetArrayDim is a function that returns an integer, which is the size of the array
    'of that field name. For test purpose, retun a constant
    Public Function GetArrayDim() As Integer
        Return 1
    End Function

    Public Sub DimArrays()
        ReDim MyBS(3)
        Dim i As Integer
        For i = 0 To MyBS.Length - 1
            'Try to ReDim the member of MyBS
            ReDim MyBS(i).GetType.GetField(ReadFieldString)(GetArrayDim)
        Next()
    End Sub

End Class

ReDim 语句出现错误“表达式是一个值，因此不能成为赋值的目标”。提前致谢。

Answer 1

我不确定ReDim这样的工作方式。将代码更改为此将实现我相信您所追求的：

Public Sub DimArrays()
    ReDim MyBS(3)
    Dim i As Integer
    For i = 0 To MyBS.Length - 1
        MyBS(i) = New BS()
        Dim f = GetType(BS).GetField(ReadFieldString())
        f.SetValue(MyBS(i), Array.CreateInstance(f.FieldType.GetElementType(), GetArrayDim()))
    Next
End Sub

但是，我认为更好的方法是在 BS 构造函数中指定数组大小。