图 4.1 登陆界面实现
当用户单击确定按钮后,用SQL语句查询“用户”表中是否有相符的用户名和密码,若不符合,则提示重新输入,焦点返回文本框。如果3次输入错误,则退出系统。若输入正确,将用户名和用户权限保存在全局变量中,显示系统主窗体,卸载本窗体。单击取消按钮时结束程序运行。
系统登录的代码实现:
Private Sub Form_Initialize()
ChDrive App.Path
ChDir App.Path
End Sub
Private Sub cmdCancel_Click()
End
End Sub
Private Sub cmdOk_Click()
Static interr As Integer
Dim strUser As String, strPass As String, strSQL As String
strUser = Trim$(txtUserID.Text)
strPass = Trim$(txtPassword.Text)
strSQL = "SELECT * FROM 用户 WHERE 用户名='" & strUser & "' AND 密码='" & strPass & "'"