Excel VBA不向解算器模型添加图元

我之前遇到过一个问题，就是解算器没有通过VBA将二进制约束添加到模型中……我（大部分）已经解决了这个问题。但现在我有了一个新问题。首先，让我发布违规代码的相关部分。我应该注意到这是在Excel2007中运行的

'build string of ByChange cells and set up cascading constraints
by_change_string = ""
For i = 1 To j - 1

    If Len(by_change_string) > 0 Then                   'there are already some elements in the string, so we might start with a comma
        If Not (Right(by_change_string, 1) = ",") Then  'make sure the last character isn't already a comma
            by_change_string = by_change_string & ","
        End If
    End If

    current_status = Sheets("Buyback Risk Area").Range("C1").Offset(i).Value
    Select Case current_status
        Case "Y"                'risk area is currently yellow, so green transition is available
            by_change_string = by_change_string & "$E$" & i + 1
            solverok setcell:="$B$" & j + 4, MaxMinVal:=2, ValueOf:="0", ByChange:=by_change_string

            'add binary constraints
            solveradd cellref:="$E$" & i + 1, relation:=5, formulatext:="binary"
        Case "O"                'risk area is currently orange, so green and yellow transitions are available
            by_change_string = by_change_string & "$E$" & i + 1 & ",$G$" & i + 1
            solverok setcell:="$B$" & j + 4, MaxMinVal:=2, ValueOf:="0", ByChange:=by_change_string

            'add cascading constraints
            solveradd cellref:="$E$" & i + 1, relation:=1, formulatext:="$G$" & i + 1 'says E <= G, which means you can't select green unless you've already selected yellow

            'add binary constraints
            solveradd cellref:="$E$" & i + 1, relation:=5, formulatext:="binary"'                solveradd cellref:="$G$" & i + 1, relation:=5, formulatext:="binary"
        Case "R"                'risk area is currently red, so green, yellow, and orange transitions are available
            by_change_string = by_change_string & "$E$" & i + 1 & ",$G$" & i + 1 & ",$I$" & i + 1
            'solverok setcell:="$B$" & j + 4, MaxMinVal:=2, ValueOf:="0", ByChange:=by_change_string

            'add cascading constraints
            solveradd cellref:="$E$" & i + 1, relation:=1, formulatext:="$G$" & i + 1 'says E <= G, which means you can't select green unless you've already selected yellow
            solveradd cellref:="$G$" & i + 1, relation:=1, formulatext:="$I$" & i + 1 'says G <= I, which means you can't select yellow unless you've already selected orange

            'add binary constraints
            solveradd cellref:="$E$" & i + 1, relation:=5, formulatext:="binary"
            solveradd cellref:="$G$" & i + 1, relation:=5, formulatext:="binary"
            solveradd cellref:="$I$" & i + 1, relation:=5, formulatext:="binary"
        Case "B"                'risk area is black, so green, yellow, orange and red transitions are avaailable
            by_change_string = by_change_string & "$E$" & i + 1 & ",$G$" & i + 1 & ",$I$" & i + 1 & ",$K$" & i + 1
            solverok setcell:="$B$" & j + 4, MaxMinVal:=2, ValueOf:="0", ByChange:=by_change_string

            'add cascading constraints
            solveradd cellref:="$E$" & i + 1, relation:=1, formulatext:="$G$" & i + 1 'says E <= G, which means you can't select green unless you've already selected yellow
            solveradd cellref:="$G$" & i + 1, relation:=1, formulatext:="$I$" & i + 1 'says G <= I, which means you can't select yellow unless you've already selected orange
            solveradd cellref:="$I$" & i + 1, relation:=1, formulatext:="$K$" & i + 1 'says K <= M, which means you can't select orange unless you've already selected red

            'add binary constraints
            solveradd cellref:="$E$" & i + 1, relation:=5, formulatext:="binary"
            solveradd cellref:="$G$" & i + 1, relation:=5, formulatext:="binary"
            solveradd cellref:="$I$" & i + 1, relation:=5, formulatext:="binary"
            solveradd cellref:="$K$" & i + 1, relation:=5, formulatext:="binary"
    End Select
Next i

'buyback amount constraint
solveradd cellref:="$O$" & j + 1, relation:=1, formulatext:="$B$" & j + 2

'set target cell
solverok setcell:="$B$" & j + 4, MaxMinVal:=2, ValueOf:="0", ByChange:=by_change_string

'set binary constraints
'binary_array = Split(by_change_string, ",")
'For i = 0 To UBound(binary_array)
'    solveradd cellref:=Range(binary_array(i)), relation:=5, formulatext:="binary"
'Next i


Application.ScreenUpdating = True

SolverSolve userFinish:=False

这里的想法是通过从选择的案例中获取所有那些solverok和solverad语句来提高效率。等到最后一个solverok语句之后，所有变量现在都在模型中，因此您应该能够单步遍历By_change_字符串，并将其中的每一个变为二进制变量。这样，您只需要一个SolverRok语句，就可以在选定的情况下删除所有solveradd语句。因此，我注释掉了所选案例中的所有SolverRok和SolverRadd，然后再次运行宏。我没有从解算器得到任何输出。运行后查看“解算器”对话框时，“目标单元格”和“通过更改单元格”字段均为空。这就好像最后的solverok声明从未运行过一样

然后我尝试取消对所有solverok的注释，但将solveradd留给注释掉的二进制变量。我返回到只获取前41个决策变量。设置二进制约束的循环完成了它的工作，但是solverad没有将变量输入到模型中

在这一点上我几乎被难住了。有什么想法吗？

正如我所想：

通过更改单元格参数，解算器最多只允许255个字符。如果您不相信，请尝试手动添加所需的单元格。你将无法做到这一点

可以传递解算器的最大非连续范围为51（假设每个组只有1个单元格，格式类似于

$A$1，

带有1个字母1个数字2个美元符号和1个逗号）。如果您尝试手动添加更多，它将删除以前的所有选择。假设在代码中执行此操作时，一旦满足长度约束，就会忽略所有内容

老实说，我从未使用过解算器，也不知道如何通过代码访问它。不管怎样，你试图让它做一些它做不到的事情

现在，与其只是告诉你这行不通，不如说这里有一个可能的（但在我看来是令人讨厌的）解决办法。如果我必须做你正在做的事，我会这么做。将重要的值复制到工作簿中的另一个位置，并将它们彼此相邻设置，以便可以将它们作为连续范围传递。解算器运行后，将值放回其应位于的位置

编辑：可能有点过时，但说明如下：

模型决策变量通过更改编辑单元格输入到中 盒子。Excel允许用户输入所谓的多重选择，即 最多由16个范围（矩形、行或列或单个区域）组成 单元格）用逗号分隔

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这意味着您只能对解算器使用16个非连续范围，并且希望它能够正常工作。

Daniel Cook关于问题原因的看法似乎是正确的。不过我会提出一个不同的解决办法。创建一个包含所有非连续范围的命名范围，并通过“更改”字符串将其设置为表示该命名范围的字符串。

我想在这些答案中添加以下内容：

使用代码超过最大值会在模型中留下一个空的Bychange区域

命名一个范围并不能解决问题，因为解算器会立即用其常用语言对其进行翻译，并删除窗口中无法容纳的最后一个范围

来源：我刚刚用excel 2013尝试了这些解决方案

'set binary constraints
'binary_array = Split(by_change_string, ",")
'For i = 0 To UBound(binary_array)
'    solveradd cellref:=Range(binary_array(i)), relation:=5, formulatext:="binary"
'Next i