我正在尝试制作一个基于 excel vba 的计算器，将输出结果发布到 excel 表中的特定单元格，但是当我尝试调用用户表单时发生错误编译错误：无效的外部程序我的宏代码如下
'Declare the global variables to be used throughout the form
Dim mfirst As Single
Dim msecond As Single
Dim manswer As Single
' Declare the global variables for the operators: Add,Sub,Mul and DIV
Dim mbutton As Integer
Dim ws As Worksheet
Set ws = Worksheet("entry")
ws.Range("b4").Value = manswer
'Change the sign of the number from + or - or vice versa
' Depending on its state now they show in txtNUMBER text box
Dim Signstate As Boolean
Private Sub Backspc_Click()
TXTnumber = Len(TXTnumber) - 1
End Sub
Private Sub cmd0_Click()
'Put the value 0 into the txtNUMBER text box
TXTnumber = TXTnumber + "0"
End Sub
Private Sub cmd1_Click()
'Put the value 1 into the txtNUMBER text box
TXTnumber = TXTnumber + "1"
End Sub
Private Sub cmd2_Click()
'Put the value 2 into the txtNUMBER text box
TXTnumber = TXTnumber + "2"
End Sub
Private Sub cmd3_Click()
'Put the value 3 into the txtNUMBER text box
TXTnumber = TXTnumber + "3"
End Sub
Private Sub cmd4_Click()
'Put the value 4 into the txtNUMBER text box
TXTnumber = TXTnumber + "4"
End Sub
Private Sub cmd5_Click()
'Put the value 5 into the txtNUMBER text box
TXTnumber = TXTnumber + "5"
End Sub
Private Sub cmd6_Click()
'Put the value 6 into the txtNUMBER text box
TXTnumber = TXTnumber + "6"
End Sub
Private Sub cmd7_Click()
'Put the value 7 into the txtNUMBER text box
TXTnumber = TXTnumber + "7"
End Sub
Private Sub cmd8_Click()
'Put the value 8 into the txtNUMBER text box
TXTnumber = TXTnumber + "8"
End Sub
Private Sub cmd9_Click()
'Put the value 9 into the txtNUMBER text box
TXTnumber = TXTnumber + "9"
End Sub
Private Sub cmdADD_Click()
'User slected the add button
mbutton = 1
'Convert into a number and transfer the value from
'The text box on the form into the first number
mfirst = Val(TXTnumber)
TXTnumber = ""
End Sub
Private Sub cmdSUBTRACT_Click()
'User slected the minus button
mbutton = 2
'Convert into a number and transfer the value from
'The text box on the form into the first number
mfirst = Val(TXTnumber)
TXTnumber = ""
End Sub
Private Sub cmdMULTIPLY_Click()
'User slected the multiply button
mbutton = 3
'Convert into a number and transfer the value from
'The text box on the form into the first number
mfirst = Val(TXTnumber)
TXTnumber = ""
End Sub
Private Sub cmdDIVIDE_Click()
'User slected the Divide button
mbutton = 4
'Convert into a number and transfer the value from
'The text box on the form into the first number
mfirst = Val(TXTnumber)
TXTnumber = ""
End Sub
Private Sub cmdEQUALS_Click()
msecond = Val(TXTnumber)
Select Case mbutton
Case Is = 1
manswer = mfirst + msecond
Case Is = 2
manswer = mfirst - msecond
Case Is = 3
manswer = mfirst * msecond
Case Is = 4
manswer = mfirst / msecond
End Select
TXTnumber = manswer
End Sub
Private Sub cmdDOT_Click()
TXTnumber = TXTnumber + "."
End Sub
Private Sub cmdSIGN_Click()
'Sign state = false on load of form
If TXTnumber = "-" + TXTnumber Then
MsgBox "error start again"
End If
If Signstate = False Then
TXTnumber = "-" + TXTnumber
Signstate = True
Else
'SignState = True
minusvalue = Val(TXTnumber)
'Value now positive
minusvalue = Val("-1" * minusvalue)
TXTnumber = minusvalue
Signstate = False
End If
End Sub
Private Sub cmdEXIT_Click()
Unload frmCALCULATOR
End Sub
Private Sub cmdCANCEL_Click()
'Remove the values in the txtNUMBER text box
TXTnumber = " "
End Sub