如何把字符串转换成表达式

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dim a
a =1

if text1.text then
msgbox "test"
endif



执行的时候报错，类型错误，求解决方案，勿用vbscripts

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解决了，谢谢rainstormmaster(rainstormmaster)的方法，vba6可不小啊，有没有系统里的API啊

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出现新问题，vba6 好像不是很稳定，在vb IDE中执行没问题，而编译生成EXE后，执行时报错，2000和98干净的系统都试过了，不知道为啥

[rainstormmaster]

//vba6可不小啊，有没有系统里的API
Private Declare Function EbExecuteLine Lib "vba6.dll" _
(ByVal StringToExec As Long, ByVal Any1 As Long, _
ByVal Any2 As Long, ByVal CheckOnly As Long) As Long

用的就是api函数呀，一般用户的机器上都应该有vba6.dll

[kmzs]

高手在这，就不弄斧了！

[rainstormmaster]

//执行时报错，2000和98干净的系统都试过了，不知道为啥

报什么错，是文件找不到吗？

是的话，指明vba6.dll的绝对路径

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VBA6.DLL 中导致无效页错误。
Registers:
EAX=00000000 CS=0167 EIP=0fa916aa EFLGS=00000206
EBX=00000096 SS=016f ESP=0067eccc EBP=0067ece0
ECX=0067ed84 DS=016f ESI=0067ed84 FS=2eaf
EDX=81730000 ES=016f EDI=00000096 GS=0000
Bytes at CS:EIP:
8b 08 50 ff 51 0c c2 04 00 6a 01 58 84 05 e4 c0
Stack dump:
00000096 0fa91a89 00000096 00000000 0000004b 0067ed94 0fbb6ad9 00000078 00000000 00000096 0067ed0c 00000000 00000001 0067edf4 0067f290 00000001

[TechnoFantasy]

需要首先引用 Microsoft Script Control：

在工程中创建一个class module，然后在其中加入代码：
Public k1 As Integer

在Form中添加一个TextBox，一个commandbutton和一个ScriptControl：

Private Sub Command1_Click()
Dim a(1)
Dim shar As New Class1

ScriptControl1.AddObject "sh", shar
ScriptControl1.AddCode "Function Main(x)" & vbCrLf & "kk=" & Text1.Text & vbCrLf & "sh.k1 = kk " & vbCrLf & "End Function"

ScriptControl1.Run "main", a
MsgBox "结果等于：" & shar.k1, , "运算结果"
End Sub


Private Sub Form_Load()
Text1.Text = "3+2*1"
End Sub

[rainstormmaster]

Private Declare Function EbExecuteLine Lib "vba6.dll" _
(ByVal StringToExec As Long, ByVal Any1 As Long, _
ByVal Any2 As Long, ByVal CheckOnly As Long) As Long

Dim Variable As Variant

Function ExecuteCode(Code As String, Optional CheckOnly As Boolean) As Boolean
ExecuteCode = EbExecuteLine(StrPtr(Code), 0&, 0&, CheckOnly) = 0
End Function
Private Sub cmdCheckCode_Click()
Dim Code As String
Code = Replace(txtCode.Text, vbCrLf, ":")
MsgBox ExecuteCode(Code, True)
End Sub

Private Sub cmdExecuteCode_Click()
Dim Code As String
Code = Replace(txtCode.Text, vbCrLf, ":")
Call ExecuteCode(Code)
End Sub

Private Sub Command1_Click()
MsgBox a
End Sub

Private Sub Form_Load()
txtCode.Text = "a=1+2*3" + vbCrLf + "Variable=a" + vbCrLf + "msgbox a"
Label1.Caption = "请在文本框中输一段代码，看看效果"
cmdExecuteCode.Caption = "执行代码"
cmdCheckCode.Caption = "执行结果"
End Sub

[rainstormmaster]

当然，也可以自己根据字串的内容进行解析，下面是一个例子：
http://www.freevbcode.com/code/Parser.zip

[lop008]

楼上的方法果然厉害，领教了！

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给我一个可以解决我的问题的方法，如何替代IF语句中的表达式