vb实验答案(正品).docVIP

2--1 界面如下： 程序如下： Imports System.Data Imports System.Data.OleDb Public Class Form1 Dim Right_Name, Right_Mima As String Dim i As Integer = 0 i为输入的次数 Dim Yonghm, Mima As String Public Structure Mune Dim Right_Name As String Dim Right_Mima As String End Structure Dim M(10) As Mune Dim j As Integer = 0 Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 11111 Dim cn As New OleDbConnection() cn.ConnectionString = Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\test.mdb 22222 Dim cmd As New OleDbCommand() cmd.Connection = cn cmd.CommandText = select * from Users Dim da As New OleDbDataAdapter da.SelectCommand = cmd 44444 Dim dt As New DataTable 5555555555 cn.Open() da.Fill(dt) 用适配器来填充数据集合 cn.Close() For Each dr As DataRow In dt.Rows M(j).Right_Name = dr.Item(1).ToString M(j).Right_Mima = dr.Item(2).ToString j = j + 1 Next End Sub Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim yonghm1 As String yonghm1 = Strings.RTrim(TextBox1.Text) Mima = TextBox2.Text If i = 3 And (Yonghm Right_Name Or Mima Right_Mima) Then End End If If yonghm1 = Right_Name And Mima = Right_Mima Then Me.Hide() MessageBox.Show(你好， Right_Name 欢迎使用此软件！) ElseIf yonghm1 Right_Name Then MessageBox.Show(登录信息错误，请检查后重新输入！, 提示, MessageBoxButtons.OK, MessageBoxIcon.Exclamation) TextBox1.SelectAll() TextBox1.Focus() i = i + 1 ElseIf yonghm1 = Right_Name And Mima Right_Mima Then MessageBox.Show(登录信息错误，请检查后重新输入！, 提示, MessageBoxButtons.OK, MessageBoxIcon.Exclamation) TextBox2.Sele