我有一个功能如下:
Function foo(ByVal c As CustomType, ByValue str as String) As Object
Dim o as Object
Select Case c.TypeName
Case "System.String"
If str = String.Empty Then
o = DBNull.Value
Else
o = value
End If
Case "System.Int64"
Try
o = Long.Parse(value, Globalization.NumberStyles.Any)
Catch
o = DBNull.Value
End Try
Case "System.Double"
Try
o = Double.Parse(value, Globalization.NumberStyles.Any)
Catch
o = DBNull.Value
End Try
Case "System.Int32"
Try
o = Int32.Parse(value, Globalization.NumberStyles.Any)
Catch
o = DBNull.Value
End Try
Case "System.DateTime"
Try
o = DateTime.Parse(value)
Catch
o = DBNull.Value
End Try
Return o
End Function
这个功能让我想写一个通用版本。由于像 C++ 这样的 .NET 中不允许部分专业化(如果我在这里错了,请纠正我),我可以通过哪些方式使用泛型的任何特性。我做了一个尴尬的尝试,但失败了:
Function foo(Of T)(...) as Object
Dim o As Object
Try
o = T.Parse(...) 'This doesnt work
Catch
o = DBNull.Value
End Try
...
End Function
'Add functions for handling String and DateTime maybe?