跪求VB四则运算代码
来源:百度知道 编辑:UC知道 时间:2024/09/28 08:10:07
晕死了
就把OP的值提出来放个变量里 然后做select case根据选择把text值提出来做下运算就OK啊
这个,VB安装上有例程啊,似乎叫CAL什么的,你查
VB原代码:
Private Function EvaluateExpr(ByVal expr As String) As Single
Const PREC_NONE = 11
Const PREC_UNARY = 10 ' Not actually used.
Const PREC_POWER = 9
Const PREC_TIMES = 8
Const PREC_DIV = 7
Const PREC_INT_DIV = 6
Const PREC_MOD = 5
Const PREC_PLUS = 4
Dim is_unary As Boolean
Dim next_unary As Boolean
Dim parens As Integer
Dim pos As Integer
Dim expr_len As Integer
Dim ch As String
Dim lexpr As String
Dim rexpr As String
Dim value As String
Dim status As Long
Dim best_pos As Integer
Dim best_prec As Integer
' Remove leading and trailing blanks.
expr = Trim$(expr)
expr_len = Len(expr)
If expr_len = 0 Then Exit Function
' If we find + or - now, it is a unary operator.
is_unary = True
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