Question

我正在工作并且遇到了一些障碍。对于一个我不是最强大的程序员，我刚刚接受了这个任务，但遇到了障碍（我认为它的语法但不确定）。

我们已经做了大量的研究，为一些技术不太好的顾问找到了一些数据相关性，这个VBA工具将成为他们为客户提供实时预测的快速参考。该主题与该问题无关。

我创建了一个包含值的类，然后计划是从VBA用户表单引用该类。当我引用课程时，我没有得到我存储的值，但我得到了该属性的名称。

Private Sub ddMonthOfUse_Change()

Dim mv As String

Set chillWater = New clsMonth
    With chillWater
        .Janurary = 0.7136
        .Feburary = 0.6755
        .March = 0.6528
        .April = 0.7773
        .May = 0.8213
        .June = 0.8715
        .July = 0.9
        .August = 1.0243
        .September = 1.0516
        .October = 0.8514
        .November = 0.7095
        .December = 0.6994
    End With

Set DX = New clsMonth
    With DX
        .Janurary = 0.5777
        .Feburary = 0.5536
        .March = 0.5166
        .April = 0.6112
        .May = 0.7035
        .June = 0.75
        .July = 0.8
        .August = 0.8345
        .September = 0.9333
        .October = 0.6865
        .November = 0.5976
        .December = 0.4907
    End With


    MsgBox chillWater.month

    End Sub

在课堂模块中我有这个

 Option Explicit

'property decleration
Public Janurary As Single
Public Feburary As Single
Public March As Single
Public April As Single
Public May As Single
Public June As Single
Public July As Single
Public August As Single
Public September As Single
Public October As Single
Public November As Single
Public December As Single
Public chillWater As clsMonth, DX As clsMonth

Public Property Get month() As String

month = Main.ddMonthOfUse.value

End Property

如果用户选择月份3月，而不是消息框返回值，则消息框显示＆＃34; March。＆＃34;例如，如果我替换下拉列表的引用并只输入March，我会得到值。

我无法解决这个问题。请记住，我根本不是一名经验丰富的程序员，我对这个主题有非常基本的知识，所以我可以完全离开这里。另外我应该提一下，消息框不是信息的最终用途，我只是在测试我是否正确地调用它。

Answer 1

@Mat＆＃39; sMug当选择了userform中的组合框时（比如用户选择了May），我希望消息框显示chillwater的值。可能

好的，明白了。除去所有这些，它们有毒：

Public chillWater As clsMonth, DX As clsMonth

Public Property Get month() As String

month = Main.ddMonthOfUse.value

End Property

您需要公开一个需要一个月名称的Function并返回相应字段的值。

一种方法是利用CallByName并执行以下操作：

Public Function ValueFor(ByVal monthName As String) As Single
    On Error GoTo CleanFail

    Dim instance As Object
    Set instance = Me 'CallByName can't take "Me" directly

    Dim result As Single
    result = CallByName(instance, monthName, VbGet)

CleanExit:
    ValueFor = result
    Exit Function
CleanFail:
    result = 0
    Resume CleanExit
End Function

请注意VbGet参数 - 它将使用公共字段（我刚测试过），但理想情况下，您将封装这些值并将其公开为< em> properties 。我喜欢封装我的东西：

Option Explicit

Private Type TMonth '"T" + ClassName, just by convention
    January As Single
    February As Single
    '...
    December As Single
End Type

Private this As TMonth 'the only private field you need!

'now expose a property accessor for each member:

Public Property Get January() As Single
    January = this.January
End Property

Public Property Let January(ByVal value As Single)
    this.January = value
End Property

'...

然后您的表单代码可以执行此操作：

Set chillWater = New clsMonth
With chillWater
    .Janurary = 0.7136
    .Feburary = 0.6755
    .March = 0.6528
    .April = 0.7773
    .May = 0.8213
    .June = 0.8715
    .July = 0.9
    .August = 1.0243
    .September = 1.0516
    .October = 0.8514
    .November = 0.7095
    .December = 0.6994

    MsgBox "Value for " & ddMonthOfUse.value & ": " & .ValueFor(ddMonthOfUse.Value)

End With

来自userform的vba对象引用不起作用

1 个答案: