Question

如果选项严格设置为关闭，使用方法重载是不是一个坏主意？请参阅下面的代码。 .NET中的每种数据类型都有一个单独的函数。该类可以处理Oracle和SQL服务器参数：

Public Class clsParameterValues
        'Implements IDisposable

        Private paramValues(0) As DbParameter

        Public Function AssignParameterValues(ByVal strParameterName As String, ByVal strParameterValue As Long, ByVal intDatabaseType As Integer) As Integer
            Dim intArrayBound As Integer

            intArrayBound = UBound(paramValues)
            'If intArrayBound > 0 Then
            If paramValues(0) Is Nothing = False Then
                intArrayBound = intArrayBound + 1
                ReDim Preserve paramValues(intArrayBound)
            End If
            If intDatabaseType = 1 Then
                paramValues(intArrayBound) = New SqlParameter(strParameterName, strParameterValue)
            ElseIf intDatabaseType = 2 Then
                paramValues(intArrayBound) = New OracleParameter(strParameterName, strParameterValue)
                'paramValues(intArrayBound) = New OracleParameter(":" & strParameterName, OracleType.Int32)
                'paramValues(intArrayBound).Value = strParameterValue
            End If
            paramValues(intArrayBound).DbType = DbType.Int64
            Return intArrayBound
        End Function

        Public Function AssignParameterValues(ByVal strParameterName As String, ByVal strParameterValue As Integer, ByVal intDatabaseType As Integer) As Integer
            Dim intArrayBound As Integer

            intArrayBound = UBound(paramValues)
            'If intArrayBound > 0 Then
            If paramValues(0) Is Nothing = False Then
                intArrayBound = intArrayBound + 1
                ReDim Preserve paramValues(intArrayBound)
            End If
            If intDatabaseType = 1 Then
                paramValues(intArrayBound) = New SqlParameter(strParameterName, strParameterValue)
            ElseIf intDatabaseType = 2 Then
                paramValues(intArrayBound) = New OracleParameter(strParameterName, strParameterValue)
                'paramValues(intArrayBound) = New OracleParameter(":" & strParameterName, OracleType.Int32)
                'paramValues(intArrayBound).Value = strParameterValue
            End If
            paramValues(intArrayBound).DbType = DbType.Int32
            Return intArrayBound
        End Function

        Public Function AssignParameterValues(ByVal strParameterName As String, ByVal strParameterValue As String, ByVal intDatabaseType As Integer) As Integer
            Dim intArrayBound As Integer

            intArrayBound = UBound(paramValues)
            'If intArrayBound > 0 Then
            If paramValues(0) Is Nothing = False Then
                intArrayBound = intArrayBound + 1
                ReDim Preserve paramValues(intArrayBound)
            End If
            If intDatabaseType = 1 Then
                paramValues(intArrayBound) = New SqlParameter(strParameterName, strParameterValue)
            ElseIf intDatabaseType = 2 Then
                paramValues(intArrayBound) = New OracleParameter(strParameterName, strParameterValue)
                'paramValues(intArrayBound) = New OracleParameter(":" & strParameterName, OracleType.Int32)
                'paramValues(intArrayBound).Value = strParameterValue
            End If
            paramValues(intArrayBound).DbType = DbType.String
            Return intArrayBound
        End Function

        Public Function AssignParameterValues(ByVal strParameterName As String, ByVal strParameterValue As Date, ByVal intDatabaseType As Integer) As Integer
            Dim intArrayBound As Integer

            intArrayBound = UBound(paramValues)
            'If intArrayBound > 0 Then
            If paramValues(0) Is Nothing = False Then
                intArrayBound = intArrayBound + 1
                ReDim Preserve paramValues(intArrayBound)
            End If

            If intDatabaseType = 1 Then

                'paramValues(intArrayBound) = New SqlParameter(strParameterName, DateValue(strParameterValue))
                paramValues(intArrayBound) = New SqlParameter(strParameterName, strParameterValue)
            ElseIf intDatabaseType = 2 Then
                paramValues(intArrayBound) = New OracleParameter(strParameterName, strParameterValue)
                'paramValues(intArrayBound) = New OracleParameter(":" & strParameterName, OracleType.Int32)
                'paramValues(intArrayBound).Value = strParameterValue
            End If
            paramValues(intArrayBound).DbType = DbType.Date
            Return intArrayBound
        End Function

        Public Function AssignParameterValues(ByVal strParameterName As String, ByVal strParameterValue As Decimal, ByVal intDatabaseType As Integer) As Integer
            Dim intArrayBound As Integer

            intArrayBound = UBound(paramValues)
            'If intArrayBound > 0 Then
            If paramValues(0) Is Nothing = False Then
                intArrayBound = intArrayBound + 1
                ReDim Preserve paramValues(intArrayBound)
            End If

            If intDatabaseType = 1 Then

                paramValues(intArrayBound) = New SqlParameter(strParameterName, strParameterValue)
            ElseIf intDatabaseType = 2 Then
                paramValues(intArrayBound) = New OracleParameter(strParameterName, strParameterValue)
                'paramValues(intArrayBound) = New OracleParameter(":" & strParameterName, OracleType.Int32)
                'paramValues(intArrayBound).Value = strParameterValue
            End If
            paramValues(intArrayBound).DbType = DbType.Decimal
            Return intArrayBound
        End Function

        Public Function AssignParameterValues(ByVal strParameterName As String, ByVal strParameterValue As Boolean, ByVal intDatabaseType As Integer) As Integer
            Dim intArrayBound As Integer

            intArrayBound = UBound(paramValues)
            'If intArrayBound > 0 Then
            If paramValues(0) Is Nothing = False Then
                intArrayBound = intArrayBound + 1
                ReDim Preserve paramValues(intArrayBound)
            End If

            If intDatabaseType = 1 Then

                paramValues(intArrayBound) = New SqlParameter(strParameterName, strParameterValue)
            ElseIf intDatabaseType = 2 Then
                paramValues(intArrayBound) = New OracleParameter(strParameterName, strParameterValue)
                'paramValues(intArrayBound) = New OracleParameter(":" & strParameterName, OracleType.Int32)
                'paramValues(intArrayBound).Value = strParameterValue
            End If
            paramValues(intArrayBound).DbType = DbType.Boolean
            Return intArrayBound
        End Function

        Public Function getParameterValues() As DbParameter()
            Return paramValues
        End Function

    End Class

调用者有责任确保类型正确。例如，如果要创建date类型的参数，请传递日期类型。这合理吗？

Answer 1

根据MSDN，Option Strict在解析重载函数/ subs时不会改变运行时的行为。因此（并且因为你声明你涵盖了每种价值类型）在你的情况下应该无关紧要。

Answer 2

我认为这绝对是不好的做法。 IMO（你应该总是Option Strict On）。

但是，只要您根据您可能期望的数据类型覆盖每个案例，那么您的代码将起作用。正如Stephan B所说，Option Strict不会改变重载方法的解析方式。当您尝试使用一种类型的变量时，它只允许动态装箱/取消装箱和类型转换，就好像它是一种不同的类型（即，如果您尝试在String上进行数学运算）。

Option Strict Off的函数重载

2 个答案: