Visual Basic中,对于文本比较好的处理方式.

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   3195
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   4680
   LinkTopic       =   "Form1"
   ScaleHeight     =   3195
   ScaleWidth      =   4680
   StartUpPosition =   3  '窗口缺省
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub Form_Load()
    Dim s As String
    Show
    s = InputBox("请输入一个字符")
    If checha(s) Then
        Print "***输入的字符是英文字母***"
    Else
        Print "***输入的字符不是英文字母***"
    End If
End Sub
Function checha(inp As String) As Boolean
    Dim upalp As String
    upalp = UCase(inp)
    If "A" <= upalp And upalp <= "Z" Then
        checha = True
    Else
        checha = False
    End If
End Function