vbnet计算器代码

1. vb:简易计算器（加减乘除）代码

代码如下：

Dim t, t1 As Integer

Dim x, y As Double

Public Sub com()

x = Val(l1.Caption)

Select Case t1

Case Is = 1: y = y + x

Case Is = 2: y = y - x

Case Is = 3: y = y * x

Case Is = 4: y = y / x

End Select

t1 = 0

t = 0

l1.Caption = "0"

End Sub

Private Sub Form_Load()

x = 0

y = 0

t = 0

t1 = 1

End Sub

Private Sub c0_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "0"

Else

l1.Caption = l1.Caption + "0"

End If

End Sub

Private Sub C1_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "1"

Else

l1.Caption = l1.Caption + "1"

End If

End Sub

Private Sub c10_Click(Index As Integer)

If t = 0 Then

l1.Caption = l1.Caption + "."

t = 1

End If

End Sub

Private Sub C2_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "2"

Else

l1.Caption = l1.Caption + "2"

End If

End Sub

Private Sub C3_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "3"

Else

l1.Caption = l1.Caption + "3"

End If

End Sub

Private Sub C4_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "4"

Else

l1.Caption = l1.Caption + "4"

End If

End Sub

Private Sub C5_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "5"

Else

l1.Caption = l1.Caption + "5"

End If

End Sub

Private Sub C6_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "6"

Else

l1.Caption = l1.Caption + "6"

End If

End Sub

Private Sub C7_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "7"

Else

l1.Caption = l1.Caption + "7"

End If

End Sub

Private Sub C8_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "8"

Else

l1.Caption = l1.Caption + "8"

End If

End Sub

Private Sub C9_Click(Index As Integer)

If l1.Caption = "0" Then

l1.Caption = "9"

Else

l1.Caption = l1.Caption + "9"

End If

End Sub

Private Sub z1_Click(Index As Integer)

com

t1 = 1

End Sub

Private Sub z2_Click(Index As Integer)

com

t1 = 2

End Sub

Private Sub z3_Click(Index As Integer)

com

t1 = 3

End Sub

Private Sub z4_Click(Index As Integer)

com

t1 = 4

End Sub

Private Sub z5_Click(Index As Integer)

tmp = Mid(l1.Caption, Len(l1.Caption), 1)

If tmp = "." Then

t = 0

End If

If Len(l1.Caption) = 1 Then

l1.Caption = "0"

Else

l1.Caption = Left(l1.Caption, Len(l1.Caption) - 1)

End If

End Sub

Private Sub z6_Click(Index As Integer)

l1.Caption = "0"

Form_Load

End Sub

Private Sub z7_Click(Index As Integer)

If (l1.Caption <> "0") Then

l1.Caption = "-" + l1.Caption

End If

End Sub

Private Sub z8_Click(Index As Integer)

com

l1.Caption = Str(y)

End Sub

(1)vbnet计算器代码扩展阅读

语言缺点

Visual Basic 语言具有不支持继承、无原生支持多线程、异常处理不完善等三项明显缺点，使其有所局限性（此些缺点皆已在 vb .net 获得改进）。

不支持继承

VB 5.0 和 VB 6.0 都是基于对象的编程语言，但是不包含继承特性。VB 中提供了特殊的类的功能，但是还是不能满足程序员的需求。

无原生支持多线程

Visual Basic 对于多线程无原生支持，只能通过Windows API的调用实现，且极其的不稳定。因为在API创建的线程中，并没有自动初始化运行时库，导致部分的函数无法使用。一般的，在VB6等早期的VB开发环境下，使用API创建线程的目的是完成容易使程序假死的大量数据或者逻辑的计算。

异常处理不完善

Visual Basic 中内置异常处理，即使未写异常处理代码，一旦用户出错也会弹出一个明确写出出错原因对话框，接着程序终止。

Visual Basic 中可以使用 Err.Raise抛出异常。对系统及用户抛出的异常的处理常用两种模式：一是使用 On Error Resume Next 处理错误；另一种是使用 On Error Goto 将运行引入错误处理代码。但相对 C++ 等语言而言，这样的异常处理破坏了代码的结构。