1.配置SQLServer外围应用服务器,开启SQL2005远程连接功能：
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操作方式如下，点击“配置工具”-“SQLServer外围应用配置器”，然后在打开的窗口中选择“服务和连接的外围应用配置器”-然后选择Database Engine节点下的 “远程连接”，选择“本地连接和远程连接”，同时选择“同时使用TCP/IP和named pipes”，确定后然后需要重新启动数据库服务就可以了。
2.把登陆设置改为SQLServer 和 Windows 身份验证模式，具体设置如下:
打开SQLServer Management Studio管理器，点击服务器上面右键然后查看属性，在安全性选项里面对服务身份验证选择“SQLServer 和 Windows 身份验证模式”。
步骤如下：
窗体上添加2个列表框，一个按钮：
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim MyDir As String = "C:\123"
'搜索并显示子文件夹
ListBox1.Items.Clear()
For Each MySubDir As String In System.IO.Directory.GetDirectories(MyDir)
ListBox1.Items.Add(MySubDir)
Next
'搜索并显示文件
ListBox2.Items.Clear()
For Each MyFile As String In System.IO.Directory.GetFiles(MyDir)
ListBox2.Items.Add(MyFile)
Next
End Sub
End Class
1 生成txt文件。
DimSaveFileDialog1AsNewSaveFileDialog() '创建一个保存对话框
SaveFileDialog1.Filter ="txt files (*.txt)|*.txt" '设置扩展名
IfSaveFileDialog1.ShowDialog() = System.Windows.Forms.DialogResult.OKThen '如果确定保存
My.Computer.FileSystem.WriteAllText(SaveFileDialog1.Filename, Textbox1.Text,False) '保存文本,False表示不追加文本，直接覆盖其内容
EndIf
原文链接：
Imports System.Data.OleDb
'Imports System.Data.OracleClient
Imports System.Data.SqlClient
'链接Oracle
'cn = New SqlConnection(""Data Source=TNS名称;Persist Security Info=True;User ID=用户名;Password=密码;" ")
'Imports System.Data.OracleClient
'Dim oOracleConn As OracleConnection = New OracleConnection()
'oOracleConn.ConnectionString = ""Data Source=MyOracleDB; User Id=username; Password=passwd; Integrated Security=no; "
'oOracleConn.Open()
'链接SQL Server
'cn = New SqlConnection("Data Source=.;Initial Catalog=Sales;Integrated Security=False;User ID=sa;Password=;")
'链接Access
'cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" db_path ";Persist Security Info=False")
Public Class Fun_DataBase
Dim cn As OleDbConnection
Dim cm As OleDbCommand
Dim da As OleDbDataAdapter
Dim ds As DataSet
Dim db_path As String = "D:\Documents\Visual Studio 2013\Projects\VBnet1\VBnet1\Resources\Database1.mdb"
Function Fun_sql1(Str_sql As String, V_调用来源 As String) '按指定sql，反馈1个查询值
Try
'Dim cn As New OleDbConnection("Data Source=.;Initial Catalog=Sales;Integrated Security=False;User ID=sa;Password=123456;")
'链接Access
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" db_path ";Persist Security Info=False")
cn.Open() 'sql语句执行前，必须打开连接
cm = New OleDbCommand(Str_sql, cn)
cm.ExecuteNonQuery()
Dim strValue As String = cm.ExecuteScalar.ToString
'MessageBox.Show(strValue)
Fun_sql1 = strValue
cn.Close()
Fun_sql1 = True
Catch ex As Exception
MessageBox.Show(V_调用来源 ":执行sql语句失败！" Str_sql)
Fun_sql1 = False
End Try
End Function
Function Fun_sqln(Str_sql As String, V_调用来源 As String) '按指定sql，反馈1行n列查询值
Try
'链接Access
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" db_path ";Persist Security Info=False")
cn.Open() 'sql语句执行前，必须打开连接
Dim cmd As New OleDbCommand("select * from grade", cn)
'Dim dr As SqlDataReader
Dim dr As OleDbDataReader
dr = cmd.ExecuteReader()
Dim strDisplay As String = ""
While dr.Read()
Fun_sqln = dr(0).ToString "|"
End While
cn.Close()
Fun_sqln = True
Catch ex As Exception
MessageBox.Show(V_调用来源 ":执行sql语句失败！" Str_sql)
Fun_sqln = False
End Try
'Dim s = Split(F.Fun_sqln("ef"), "|")
'Dim i As Integer
'i = UBound(s)
'For i = 0 To UBound(s)
' MessageBox.Show(s(i))
'Next
End Function
Public Function Fun_sql_exec(Str_sql As String, V_调用来源 As String) '执行指定sql，反馈T|F
Try
'链接Access
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" db_path ";Persist Security Info=False")
cn.Open() 'sql语句执行前，必须打开连接
cm = New OleDbCommand(Str_sql, cn)
cm.ExecuteNonQuery()
cn.Close()
Fun_sql_exec = True
Catch ex As Exception
MessageBox.Show(V_调用来源 ":执行sql语句失败！" Str_sql)
Fun_sql_exec = False
End Try
End Function
解压密码：1299
假设路径为C:\abc
代码：
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim Files As ObjectModel.ReadOnlyCollection(Of String) = My.Computer.FileSystem.GetFiles("C:\abc")
Dim FileSize As Long, FileName As String = Nothing
Dim oFileSize As Long
For Each File As String In Files
oFileSize = My.Computer.FileSystem.GetFileInfo(File).Length
If oFileSize FileSize Then
FileSize = oFileSize
FileName = File
End If
Next
Dim ListN As ListViewItem = New ListViewItem(My.Computer.FileSystem.GetName(FileName))
ListN.SubItems.Add(oFileSize " byte")
ListN.SubItems.Add(My.Computer.FileSystem.GetFileInfo(FileName).Extension " 文件")
ListN.SubItems.Add(FileName)
ListView1.Items.Add(ListN)
End Sub
End Class
详见源代码！！
关闭窗体触发Disposed事件，你为啥要获取form1对象，然后再来个form1 = nothing？？你这是想要释放资源吗？而且你就算来个form1 = nothing，也不代表是释放资源啊，你只是将form1的引用改了，原来指向的实例化对象依然还在，还是要靠.NET的GC回收。.NET不是有GC吗？为啥要多此一举呢？当然你要获得实例化对象也可以，在FormClass1中添加静态变量，在实例化的同时，将实例化对象赋值给静态变量，然后，在你想使用该实例化对象的时候，直接FormClass1.静态变量 就行啦。