使用数据对象的动态Linq。如何将Int32转换为String以调用String.Contains（）

我使用动态Linq对Linq执行一个T-SQL where子句。除了试图转换LIKE语句外，这非常有效，我已经手动尝试使用本文末尾包含的函数来转换LIKE语句。这段代码甚至还不够完美，但当我意识到在测试过程中会出现错误时，我停止了编程。执行的代码基本上是这样的：

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

“trx\u没有像'%3500%'”

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

并将其转换为：

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

“trx\u编号包含（“3500”）”

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

要执行此操作：

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

尺寸x=y，其中（“trx\U编号包含（“3500”），无任何内容）

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

错误：

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

类型“Int32”中不存在适用的方法“Contains”

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

我认为问题是，我需要将“trx_no”（Int32的一个可空值）转换为字符串，因此经过两天的研究和阅读，我认为我需要将该字符串转换为委托函数，而我无法使用该函数

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

我也尝试在这个链接中使用Cast-like，但是失败了，出现了一个错误：

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

应为“布尔”类型的表达式

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

我的版本如下：

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

Dim x=y.Where（“DirectCast（trx\u no，System.String）如“%35000%”，无任何内容）

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

如果我没有包括足够的代码，我很抱歉，我只是不想让这成为压倒性的。如有任何建议，将不胜感激。多谢各位

`Private Function replaceLike(ByVal str As String) As String
    Dim rtn As String = ""
    If str.ToUpper.Contains(" LIKE '") Then
        Dim firstQuote As Int32 = str.ToUpper.IndexOf(" LIKE '") + 6
        If str.ToUpper.Chars(firstQuote + 1) = Chr(37) Then
            'If the character after the first single quote is a %, this is a Contains or EndsWith
            Dim secondQuote As Int32 = str.ToUpper.IndexOf("'", firstQuote + 1)
            If str.ToUpper.Chars(secondQuote - 1) = Chr(37) Then
                'Handles '%%', '%value%', '%'
                'Found % before the last quote, this is a Contains or has the value of '%'.
                Dim val = ""
                'See if the value is empty so that we can extract the value
                Select Case (secondQuote - 1) - (firstQuote + 1)
                    Case 0
                        'Has no value don't add
                    Case 1
                        'Has no value don't add
                    Case Else
                        val = str.Substring(firstQuote + 2, ((secondQuote - 2) - firstQuote - 1))
                End Select
                str = str.Remove(firstQuote - 6, secondQuote - (firstQuote - 7))
                str = str.Insert(firstQuote - 6, ".Contains(""" & val & """) ")
            Else
                'Handles '%value'
                'Did not find another % before the last quote, this is a EndsWith
                Dim val = str.Substring(firstQuote + 2, ((secondQuote - 2) - firstQuote - 1))
                str = str.Remove(firstQuote - 6, secondQuote - (firstQuote - 7))
                str = str.Insert(firstQuote - 6, ".EndsWith(""" & val & """) ")
            End If

        Else
            'Else the character after the first single quote is not a %, this is a StartWith or is Empty
            Dim secondQuote As Int32 = str.ToUpper.IndexOf("'", firstQuote + 1)
            If str.ToUpper.Chars(secondQuote - 1) = Chr(37) Then
                'Handles 'value%'
                'Found a % before the last quote, this is a StartsWith
                Dim val = str.Substring(firstQuote + 2, ((secondQuote - 2) - firstQuote - 1))
                str = str.Remove(firstQuote - 6, secondQuote - (firstQuote - 7))
                str = str.Insert(firstQuote - 6, ".StartsWith(""" & val & """) ")
            Else
                'Handles ''
                'Found no %
                str = str.Remove(firstQuote - 6, secondQuote - (firstQuote - 7))
                str = str.Insert(firstQuote - 6, ".Contains("""") ")
            End If
        End If
        rtn = replaceLike(str)
    Else
        Return str
    End If

    Return rtn
End Function

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

---

我发现动态Linq库中预定义的类型支持Convert，我使用Convert来表示以下内容：

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

“Convert.ToString（“&propertyName&”）包含（“&val&”）

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select

如果上面的propertyName是可空类型，则这会导致将可空（Of）转换为字符串的问题。在ParseMemberAccess方法的动态Linq库中编辑Dynamic.vb代码允许转换工作。下面是在该方法中对Select Case语句所做的编辑：

            Select Case FindMethod(type, id, instance Is Nothing, args, mb)
                Case 0
                    Throw ParseError(errorPos, Res.NoApplicableMethod, id, GetTypeName(type))
                Case 1
                    Dim method = DirectCast(mb, MethodInfo)
                    If (Not IsPredefinedType(method.DeclaringType)) Then
                        Throw ParseError(errorPos, Res.MethodsAreInaccessible, GetTypeName(method.DeclaringType))
                    End If
                    If method.ReturnType.Equals(GetType(Void)) Then
                        Throw ParseError(errorPos, Res.MethodIsVoid, id, GetTypeName(method.DeclaringType))
                    End If
                    Dim newargs As Expression() = args
                    For Each a As Expression In args
                        If a.Type.IsGenericType AndAlso a.Type.GetGenericTypeDefinition = GetType(Nullable(Of )) Then
                            newargs(Array.IndexOf(args, a)) = System.Linq.Expressions.Expression.Convert(a, GetType(Object))
                        Else
                            newargs(Array.IndexOf(args, a)) = a
                        End If
                    Next
                    Return Expression.Call(instance, DirectCast(method, MethodInfo), newargs)
                Case Else
                    Throw ParseError(errorPos, Res.AmbiguousMethodInvocation, id, GetTypeName(type))
            End Select