3-2.frm

Visual Basic课程举例1 有很好的例题

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "3-2"
   ClientHeight    =   2880
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   3600
   BeginProperty Font 
      Name            =   "宋体"
      Size            =   12
      Charset         =   134
      Weight          =   400
      Underline       =   0   'False
      Italic          =   0   'False
      Strikethrough   =   0   'False
   EndProperty
   LinkTopic       =   "Form1"
   ScaleHeight     =   2880
   ScaleWidth      =   3600
   StartUpPosition =   3  '窗口缺省
   Begin VB.CommandButton Command1 
      Caption         =   "计算y的值"
      Height          =   375
      Left            =   360
      TabIndex        =   2
      Top             =   720
      Width           =   2775
   End
   Begin VB.TextBox Text1 
      Height          =   375
      Left            =   1320
      TabIndex        =   0
      Top             =   240
      Width           =   735
   End
   Begin VB.Label Label2 
      Appearance      =   0  'Flat
      BackColor       =   &H80000005&
      BorderStyle     =   1  'Fixed Single
      ForeColor       =   &H80000008&
      Height          =   1095
      Left            =   360
      TabIndex        =   3
      Top             =   1320
      Width           =   2895
   End
   Begin VB.Label Label1 
      Caption         =   "N=?"
      Height          =   255
      Left            =   480
      TabIndex        =   1
      Top             =   240
      Width           =   735
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub Command1_Click()
    
    n = Val(Text1)
    If n < 0 Then
        y = 3 * n + 2
    ElseIf n = 0 Then
        y = 0
    Else
        y = 2 * n - 1
    End If
    
    Label2.Caption = "y=" & Format(y)
End Sub