VB实例讲解二.doc

内容：?????? 做个登陆程序，以VB+Access。功能：??????1、验证。验证用户名的正确与否、密码与用户名符合与否??????2、人性化设计。????????????①、输入用户名后，无论是鼠标移动到密码框，还是按“Tab”键到密码框，都搜索用户名的存在与否，但不报错????????????②、输入密码后，选者状态在“确定”按钮上。????????????③、确定后检验，用户名为空时，光标停在用户名框，密码空停密码输入框。控件：??????TextBox、CommandButton、PictureBox、Timer、ADO程序内容：①：控件???? 2???? TextBox???? 2???? CommandButton???? 1???? PictureBox???? 1???? Timer②：程序?????? form1程序Private Sub Command1_Click()?? Unload MeEnd Sub Private Sub Command2_Click()?? Dim ConStr As String?? If text_user.Text = Then??????MsgBox 请输入用户名!, vbOKOnly + vbExclamation, 登陆错误??????text_user.SetFocus??????Exit Sub?? End If?????? Set cn = New ADODB.Connection?? Set rs = New ADODB.Recordset?? ConStr = Provider=Microsoft.Jet.OLEDB.4.0; Data Source= App.Path \ttj02.Mdb?? cn.Open ConStr?? cn.CursorLocation = adUseServer?? rs.Open Select * from dbuser, cn, adOpenKeyset, adLockPessimistic?? If rs.RecordCount 0 Then??????If text_user.Text Then???????? Set rs1 = New ADODB.Recordset???????? Dim TextUserName???????? TextUserName = Left(text_user.Text, 4)???????? rs1.Open Select * From dbuser Where User_nb= TextUserName , cn, adOpenKeyset, adLockPessimistic???????? If rs1.RecordCount 0 Then????????????text_user.Text = Left(text_user.Text, 4) rs1.Fields(user_zhuwu)????????????Text_password.SetFocus????????????If Text_password Then?????????????? If rs1.Fields(User_Nb) = TextUserName And rs1.Fields(User_password) = Text_password.Text Then??????????????????Form3.Show??????????????????Unload Me?????????????? Else??????????????????MsgBox 密码错误!, vbExclamation + vbOKCancel, 登陆错误??????????????????text_user.Text = ??????????????????Text_password = ??????????????????text_user.SetFocus?????????????? End If????????????Else?????????????? MsgBox 请输入密码!, vbExclamation + vbOKCancel, 登陆错误????????????End If???????? Else????????????MsgBox 沒有用戶信息,請確定!, vbExclamation + vbOKCancel, 登陆错误????????????text_user.Text = ????????????Text_password = ????????????t