1、vb.net 完全符合面向对象的编程语言抽象、封装、继承的四大特性，而vb不支持继承。
让客户满意是我们工作的目标，不断超越客户的期望值来自于我们对这个行业的热爱。我们立志把好的技术通过有效、简单的方式提供给客户，将通过不懈努力成为客户在信息化领域值得信任、有价值的长期合作伙伴，公司提供的服务项目有：域名注册、网页空间、营销软件、网站建设、会昌网站维护、网站推广。
2、错误处理不同。
vb中只是On Error.....goto和On Errer Resume Next ，这些错误称为非结构化异常处理。而在vb.net中采用的结构化异常处理机制，try...catch....finally控制。
3、两者产生的窗体不同。
vb.net 允许创建不同类型的应用程序，例如，创建ASP.NET和ASP.NET Web 服务应用程序，还允许创建控制台应用程序和作为桌面服务运行的应用程序。但是vb 只能创建Windows窗体。
4、数据库访问的差别。
vb6.0是通过ADO（Active X Data Objext）来实现对数据库访问。而vb.net 是通过ADO.NET来访问数据库。
扩展资料
Visual Basic（简称VB）是Microsoft公司开发的一种通用的基于对象的程序设计语言，为结构化的、模块化的、面向对象的、包含协助开发环境的事件驱动为机制的可视化程序设计语言。是一种可用于微软自家产品开发的语言。
“Visual” 指的是开发图形用户界面 (GUI) 的方法——不需编写大量代码去描述界面元素的外观和位置，而只要把预先建立的对象add到屏幕上的一点即可。
“Basic”指的是 BASIC (Beginners All-Purpose Symbolic Instruction Code) 语言，是一种在计算技术发展历史上应用得最为广泛的语言。
Visual Basic源自于BASIC编程语言。VB拥有图形用户界面（GUI）和快速应用程序开发（RAD）系统，可以轻易的使用DAO、RDO、ADO连接数据库，或者轻松的创建Active X控件，用于高效生成类型安全和面向对象的应用程序 。
参考资料：百度百科-Visual Basic
参考一下下面这段代码就可以了。
Imports System.Data
'引入数据库操作类命名空间
Imports System.Data.OleDb
'引入ADO.NET操作命名空间
Public Class FrmModifystInfo
Inherits System.Windows.Forms.Form
Public ADOcmd As OleDbDataAdapter
Public ds As DataSet = New DataSet()
'建立DataSet对象
Public mytable As Data.DataTable
'建立表单对象
Public myrow As Data.DataRow
'建立数据行对象
Public rownumber As Integer
'定义一个整型变量来存放当前行数
Public SearchSQL As String
Public cmd As OleDbCommandBuilder
'======================================================
#Region " Windows 窗体设计器生成的代码 "
#End Region
'======================================================
Private Sub FrmModifystInfo_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
'窗体的载入
TxtSID.Enabled = False
TxtName.Enabled = False
ComboSex.Enabled = False
TxtBornDate.Enabled = False
TxtClassno.Enabled = False
TxtRuDate.Enabled = False
TxtTel.Enabled = False
TxtAddress.Enabled = False
TxtComment.Enabled = False '设置信息为只读
Dim tablename As String = "student_Info "
SearchSQL = "select * from student_Info "
ExecuteSQL(SearchSQL, tablename) '打开数据库
ShowData() '显示记录
End Sub
Private Sub ShowData()
'在窗口中的textbox中显示数据
myrow = mytable.Rows.Item(rownumber)
TxtSID.Text = myrow.Item(0).ToString
TxtName.Text = myrow.Item(1).ToString
ComboSex.Text = myrow.Item(2).ToString
TxtBornDate.Text = Format(myrow.Item(3), "yyyy-MM-dd ")
TxtClassno.Text = myrow.Item(4).ToString
TxtTel.Text = myrow.Item(5).ToString
TxtRuDate.Text = Format(CDate(myrow.Item(6)), "yyyy-MM-dd ")
TxtAddress.Text = myrow.Item(7).ToString
TxtComment.Text = myrow.Item(8).ToString
End Sub
Private Sub BtFirst_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtFirst.Click
'指向第一条数据
rownumber = 0
ShowData()
End Sub
Private Sub BtPrev_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtPrev.Click
'指向上一条数据
BtNext.Enabled = True
rownumber = rownumber - 1
If rownumber 0 Then
rownumber = 0 '如果到达记录的首部，行号设为零
BtPrev.Enabled = False
End If
ShowData()
End Sub
Private Sub BtNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtNext.Click
'指向上一条数据
BtPrev.Enabled = True
rownumber = rownumber + 1
If rownumber mytable.Rows.Count - 1 Then
rownumber = mytable.Rows.Count - 1 '判断是否到达最后一条数据
BtNext.Enabled = False
End If
ShowData()
End Sub
Private Sub BtLast_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtLast.Click
'指向最后一条数据
rownumber = mytable.Rows.Count - 1
ShowData()
End Sub
Private Sub BtDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtDelete.Click
mytable.Rows.Item(rownumber).Delete() '删除记录
If MsgBox( "确定要删除改记录吗？ ", MsgBoxStyle.OKCancel + vbExclamation, "警告 ") = MsgBoxResult.OK Then
cmd = New OleDbCommandBuilder(ADOcmd)
'使用自动生成的SQL语句
ADOcmd.Update(ds, "student_Info ")
BtNext.PerformClick()
End If
End Sub
Private Sub BtModify_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtModify.Click
TxtSID.Enabled = False '关键字段只读
TxtName.Enabled = True '可读写
ComboSex.Enabled = True
TxtBornDate.Enabled = True
TxtClassno.Enabled = True
TxtRuDate.Enabled = True
TxtTel.Enabled = True
TxtAddress.Enabled = True
TxtComment.Enabled = True
End Sub
Private Sub BtUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtUpdate.Click
If Not Testtxt(TxtName.Text) Then
MsgBox( "请输入姓名！ ", vbOKOnly + vbExclamation, "警告 ")
TxtName.Focus()
Exit Sub
End If
If Not Testtxt(ComboSex.Text) Then
MsgBox( "请选择性别！ ", vbOKOnly + vbExclamation, "警告 ")
ComboSex.Focus()
Exit Sub
End If
If Not Testtxt(TxtClassno.Text) Then
MsgBox( "请选择班号！ ", vbOKOnly + vbExclamation, "警告 ")
TxtClassno.Focus()
Exit Sub
End If
If Not Testtxt(TxtTel.Text) Then
MsgBox( "请输入联系电话！ ", vbOKOnly + vbExclamation, "警告 ")
TxtTel.Focus()
Exit Sub
End If
If Not Testtxt(TxtAddress.Text) Then
MsgBox( "请输入家庭住址！ ", vbOKOnly + vbExclamation, "警告 ")
TxtAddress.Focus()
Exit Sub
End If
If Not IsNumeric(Trim(TxtSID.Text)) Then
MsgBox( "请输入数字学号！ ", vbOKOnly + vbExclamation, "警告 ")
Exit Sub
TxtSID.Focus()
End If
If Not IsDate(TxtBornDate.Text) Then
MsgBox( "出生时间应输入日期格式（yyyy-mm-dd）！ ", vbOKOnly + vbExclamation, "警告 ")
Exit Sub
TxtBornDate.Focus()
End If
If Not IsDate(TxtRuDate.Text) Then
MsgBox( "入校时间应输入日期格式（yyyy-mm-dd）！ ", vbOKOnly + vbExclamation, "警告 ")
TxtRuDate.Focus()
Exit Sub
End If
myrow.Item(0) = Trim(TxtSID.Text)
myrow.Item(1) = Trim(TxtName.Text)
myrow.Item(2) = Trim(ComboSex.Text)
myrow.Item(3) = Trim(TxtBornDate.Text)
myrow.Item(4) = Trim(TxtClassno.Text)
myrow.Item(5) = Trim(TxtTel.Text)
myrow.Item(6) = Trim(TxtRuDate.Text)
myrow.Item(7) = Trim(TxtAddress.Text)
myrow.Item(8) = Trim(TxtComment.Text)
mytable.GetChanges()
cmd = New OleDbCommandBuilder(ADOcmd)
'使用自动生成的SQL语句
ADOcmd.Update(ds, "student_Info ")
'对数据库进行更新
MsgBox( "修改学籍信息成功！ ", vbOKOnly + vbExclamation, "警告 ")
TxtName.Enabled = False
ComboSex.Enabled = False
TxtBornDate.Enabled = False
TxtClassno.Enabled = False
TxtRuDate.Enabled = False
TxtTel.Enabled = False
TxtAddress.Enabled = False
TxtComment.Enabled = False '重新设置信息为只读
End Sub
Private Sub BtCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtCancel.Click
TxtSID.Enabled = False
TxtName.Enabled = False
ComboSex.Enabled = False
TxtBornDate.Enabled = False
TxtClassno.Enabled = False
TxtRuDate.Enabled = False
TxtTel.Enabled = False
TxtAddress.Enabled = False
TxtComment.Enabled = False
End Sub
Public Function ExecuteSQL(ByVal SQL As String, ByVal table As String)
Try
'建立ADODataSetCommand对象
'数据库查询函数
ADOcmd = New OleDbDataAdapter(SQL, "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\student.mdb ")
'建立ADODataSetCommand对象
ADOcmd.Fill(ds, table) '取得表单
mytable = ds.Tables.Item(0) '取得名为table的表
rownumber = 0 '设置为第一行
myrow = mytable.Rows.Item(rownumber)
'取得第一行数据
Catch
MsgBox(Err.Description)
End Try
End Function
End Class
如果楼主熟悉VB6，可以直接在项目中添加ADODB的Com引用，这样你就可以像VB6那样操作数据库了！
另外
.NET
Framework中连接数据库要用到ADO.NET。如果要操作Access数据库，要用到System.Data.OleDb命名空间下的许多类。
比如按楼主所说，“我想在textbox1中显示表一中【一些数据】字段下的第一个内容”：
'首先导入命名空间
Imports
System.Data
Imports
System.Data.OleDb
'然后在某一个事件处理程序中写：
Dim
conn
As
New
OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data
Source=数据库.accdb;Jet
OLEDB:Database
Password=MyDbPassword")
Dim
command
As
New
OleDbCommand("Select
*
From
数据表",
conn)
conn.Open()
'打开数据库连接
Dim
reader
As
OleDbDataReader
=
command.ExecuteReader()
'执行SQL语句，返回OleDbDataReader
对象
Do
While
reader.Read()
'读取一条数据
textbox1.Text
+=
reader("一些数据")
VbCrLf
Loop
reader.Close()
'关闭OleDbDataReader
conn.Close()
'关闭连接
1·绑定数据源来进行连接
2.用代码连接
先到数据库建立一个数据库和相应的表
连接数据库的代码：
Dim str As String = "Data Source=服务器名;Initial Catalog=数据库名;Persist Security Info=True;User ID=;Password="
dim conn As SqlClient.SqlConnection
try
conn = New SqlClient.SqlConnection
conn.ConnectionString = str
conn.Open()
Return True
Catch ex As Exception
MsgBox(ex.ToString)
Return False
End Try
登录代码：Dim str As String = "Data Source=服务器名;Initial Catalog=数据库名;Persist Security Info=True;User ID=;Password="
dim conn As SqlClient.SqlConnection
conn = New SqlClient.SqlConnection
conn.ConnectionString = str
conn.Open()
sqlstr = "Select * From Amd Where AmdName='" TextBox1.Text "' And AmdPwd = '" TextBox2.Text "'"
Dim sqlcmd As SqlClient.SqlCommand = New SqlClient.SqlCommand(sqlstr, conn)
Dim dr As SqlClient.SqlDataReader
dr = sqlcmd.ExecuteReader
If dr.Read = True Then '判断一条记录为真
kf.Show() '显示下个窗体
Me.Hide() ’隐藏当前窗体
Else
MessageBox.Show("输入信息有误！", "提示")
TextBox1.Text = ""
TextBox2.Text = ""
End If
