Question

vb编写简单四则运算

Private Sub Command1_Click()
Dim a As String
Dim b As String
Dim c As String
a = Text1.Text
b = Text2.Text
c = a + b
MsgBox "结果是" & c

End Sub

为什么输入 1 和2 时 结果是12？如何改正？

Answer 1

因为你的a,b.C变量定义错了,你应定为整型变量
Private Sub Command1_Click()
Dim a As integer
Dim b As integer
Dim c As integer
a =val( Text1.Text)
b = val(Text2.Text)
c = a + b
MsgBox "结果是" & c

End Sub

这样就对了,记住"+"在VB里,对字符型变量而言,其是连接符.

Answer 2

vb写的四则运算如下：
Private Sub Command1_Click()
On Error GoTo err

Dim s As Object
Dim Bds As String '表达式

Set s = CreateObject("MSScriptControl.ScriptControl")
s.Language = "VBScript"
Bds = Text1

Text2 = s.Eval(Bds)
Exit Sub

err:
Text2 = err.Description

End Sub

Answer 3

楼上的说对了，不再重复！