Question

VB程序设计

1. 登录界面如图1.1所示。窗体上有2个标签，2个文本框（Text1、Text2）和1个命令按钮。Text1用来输入口令（输入时显示为“*”），Text2的初始内容为3，当在Text1中输入正确口令“psw123”时，弹出对话框显示“口令正确”，否则弹出如图1.2所示的错误提示框，并将Text2中的数值减1，最多可输入3次口令。如果3次都输入错误，则弹出图1.3所示对话框，单击“确定”按钮退出程序。（15分）

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Answer 1

Private Sub Command1_Click()

Static n As Long, m As Long

m = Val(Text2)

n = n + 1

If Text1 = "psw123" Then

MsgBox "口令正确", vbExclamation, "登录"

n = 0

Else

If n >= m Then

MsgBox n & "次输入错误，请退出", vbExclamation, "登录"

End

Else

MsgBox "第" & n & "次口令输入错误，请重新输入", vbExclamation, "登录"

Text1.SetFocus

End If

End If

End Sub

Private Sub Form_Load()

Label1.Caption = "口令："

Label2.Caption = "允许输入口令的次数："

Command1.Caption = "确定"

Me.Caption = "登录"

Text1 = ""

Text1.PasswordChar = "*"

Text2 = 3

End Sub