16.情報員小王在工作時發現R國會用一些對稱字符(如ABBA、ABA、123321)進行通信.R國為防止通信內容被破解,會在對稱字符的頭、尾加一些無關字符,如:12ABBA,ABAKK、51233214.因此小王編寫了一個VB程序,用于讀取通信字符串中最長的對稱字符.在文本框Text1中輸入通信字符,單擊”讀取“按鈕Command1,在標簽Label1中顯示最長的對稱字符,程序運行界面如圖所示. 實現上述功能的VB程序如下,但加框處代碼有錯,請改正. Private Sub Command1-Click( ) Dim x As String,n As Intrger,i As Integer,k As Integer Dim start As Integer,max As Integer max=0 start=1 x=Textl.Text n=Len(x) For i=l To n k=n Do While k>i If Then'(1) max=k-i+1 start=i End If '(2) Loop Next i Labell.Caption=''最長對稱字符:''+Mid(x,start,max) End Sub Function palin(temp As String)As Boolean '判斷字符串是否對稱,若對稱返回值True,否則返回值False '代碼略 End Function.