建個(gè)模塊， Dim varcnn As OleDb.OleDbConnection ReadOnly Property cnn() As OleDb.OleDbConnection
創(chuàng)新互聯(lián)公司是專業(yè)的雜多網(wǎng)站建設(shè)公司，雜多接單;提供網(wǎng)站制作、成都網(wǎng)站制作,網(wǎng)頁設(shè)計(jì),網(wǎng)站設(shè)計(jì),建網(wǎng)站,PHP網(wǎng)站建設(shè)等專業(yè)做網(wǎng)站服務(wù);采用PHP框架,可快速的進(jìn)行雜多網(wǎng)站開發(fā)網(wǎng)頁制作和功能擴(kuò)展;專業(yè)做搜索引擎喜愛的網(wǎng)站,專業(yè)的做網(wǎng)站團(tuán)隊(duì),希望更多企業(yè)前來合作!
Get
If varcnn Is Nothing OrElse varcnn.State ConnectionState.Open Then Dim cnstr As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=""" My.Application.Info.DirectoryPath "\Contact.mdb"";Persist Security Info=True"
varcnn = New OleDbConnection(cnstr)
varcnn.Open()
End If
Return varcnn
End Get
登錄窗體，新建一個(gè)就行了。代碼Public Class LoginForm1
Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click
Using cmd As New OleDb.OleDbCommand("select password from tbuser where userid =?", cnn)
cmd.Parameters.Add("?", OleDbType.VarChar).Value = Me.UsernameTextBox.Text
Dim obj As Object = cmd.ExecuteScalar
If (Not IsDBNull(obj)) AndAlso (obj IsNot Nothing) AndAlso obj = PasswordTextBox.Text Then
Me.DialogResult = Windows.Forms.DialogResult.OK
Else MessageBox.Show("密碼不正確！") Return
End If
End Using Me.Close()
End Sub Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel.Click
Me.DialogResult = Windows.Forms.DialogResult.Cancel
Me.Close()
End SubEnd Class 項(xiàng)目屬性里點(diǎn)查看應(yīng)用程序事件，寫代碼Namespace My ' 以下事件可用于 MyApplication:
'
' Startup: 應(yīng)用程序啟動(dòng)時(shí)在創(chuàng)建啟動(dòng)窗體之前引發(fā)。
' Shutdown: 在關(guān)閉所有應(yīng)用程序窗體后引發(fā)。如果應(yīng)用程序異常終止，則不會(huì)引發(fā)此事件。
' UnhandledException: 在應(yīng)用程序遇到未處理的異常時(shí)引發(fā)。
' StartupNextInstance: 在啟動(dòng)單實(shí)例應(yīng)用程序且應(yīng)用程序已處于活動(dòng)狀態(tài)時(shí)引發(fā)。
' NetworkAvailabilityChanged: 在連接或斷開網(wǎng)絡(luò)連接時(shí)引發(fā)。
Partial Friend Class MyApplication
Private Sub MyApplication_Startup(ByVal sender As Object, ByVal e As Microsoft.VisualBasic.ApplicationServices.StartupEventArgs) Handles Me.Startup
Dim f As New LoginForm1
If Not f.ShowDialog = DialogResult.OK Then
End
End If
End Sub End ClassEnd Namespace
你測(cè)試一下吧。
這個(gè)問題好寬泛，簡(jiǎn)單說下步驟吧：
簡(jiǎn)單來說，直接連接需要使用SQLConnection、SQLDataAdapter、SQLCommand、Datatable四個(gè)控件，先寫好連接字符串，然后建立連接，寫好SQL語句，通過DataAdapter從數(shù)據(jù)庫讀取數(shù)據(jù)到Datatable。這樣只有在SQL服務(wù)器中附加數(shù)據(jù)庫才能實(shí)現(xiàn)訪問。還可以使用DSN實(shí)現(xiàn)數(shù)據(jù)庫連接，控件依次更換為ODBCConnection、ODBCDataAdapter、ODBCCommand、datatable、基本步驟和上面說的一樣。
SQL語句就是從數(shù)據(jù)庫查用戶名對(duì)應(yīng)的密碼，將數(shù)據(jù)從數(shù)據(jù)庫讀取到DataTable后，與用戶輸入的密碼比對(duì)，相符則登陸成功，否則提示錯(cuò)誤。
過程中的細(xì)節(jié)問題歡迎追問
Label1.Caption = "融通系統(tǒng)外掛程序"
If Dir(App.Path "/hjw.mdb") "" Then
Set mydata = OpenDatabase(App.Path "\hjw")
Set myrs1 = mydata.OpenRecordset("user", dbOpenTable)
Else
Set mydata = CreateDatabase(App.Path "\hjw", dbLangGeneral, dbVersion40)
mydata.Execute "create table ku (建立日期 text(100),庫名 text(100),功能 text(100))"
mydata.Execute "create table system (店號(hào) integer,建立日期 text(100),文件路徑 text(100),軟件版本 text(100),路徑1 text(50),路徑2 text(50),路徑3 text(50),路徑4 text(50))"
kuname = "system"
kugn = "文件信息"
Me.showlist1
mydata.Execute "create table user (user text(50),passwd text(50),name text(50),quanx integer)"
kuname = "user"
kugn = "用戶信息"
Me.showlist1
Private Sub cmdOK_Click()
txtUserName.SetFocus
If Trim(txtUserName.Text = "") Then
MsgBox "沒有這個(gè)用戶，請(qǐng)重新輸入用戶名！", vbOKOnly + vbExclamation, "警告"
txtUserName.SetFocus
Else
sql = "select * from user where user = '" txtUserName.Text "'"
'Debug.Print sql
'Set mrc = ExecuteSQL(sql, MsgText)
Set myrs2 = mydata.OpenRecordset(sql)
If myrs2.EOF = True Then
MsgBox "沒有這個(gè)用戶，請(qǐng)重新輸入用戶名!", vbOKOnly + vbExclamation, "警告"
txtUserName.SetFocus
Else
If Trim(myrs2.Fields(1)) = Trim(txtPassword.Text) Then
UserName = myrs2.Fields(2)
myrs2.Close
Me.Hide
' UserName = Trim(txtUserName.Text)
'Debug.Print UserName
MDIform1.Show
Else
MsgBox "輸入密碼不正確，請(qǐng)重新輸入！", vbOKOnly + vbExclamation, "警告"
txtPassword.SetFocus
txtPassword.Text = ""
End If
End If
End If
End Sub
重慶分公司
重慶分公司
