form1.frm

Visual Basic程序设计视频教程

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   1185
   ClientLeft      =   60
   ClientTop       =   360
   ClientWidth     =   3420
   LinkTopic       =   "Form1"
   ScaleHeight     =   1185
   ScaleWidth      =   3420
   StartUpPosition =   3  '窗口缺省
   Begin VB.TextBox Text1 
      Height          =   495
      Left            =   240
      MaxLength       =   1
      TabIndex        =   1
      Top             =   240
      Width           =   1095
   End
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   495
      Left            =   1680
      TabIndex        =   0
      Top             =   240
      Width           =   1215
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Function IsNum(ByVal A As String)
    Select Case A
    Case "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
        IsNum = True
    Case Else
        IsNum = False
    End Select
End Function

Private Sub Command1_Click()
    If IsNum(Text1.Text) Then
        MsgBox "是数字"
    Else
        MsgBox "不是数字"
    End If
End Sub