vb.net中如何更改datagridview的数据源？

自己在学vb，做一个窗口，完成查询功能，代码如下
Private Sub Frm查询课程信息_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.LessonTableTableAdapter1.Fill(学生管理DataSet.LessonTable)
        ComboBox1.SelectedIndex = 3
    End Sub
有四列分别是课程号，课程名，院系号，备注

下面的是确定的click事件代码
Dim stritem As String
        If (ComboBox1.Text = "" Or TextBox1.Text = "") And (ComboBox1.Text <> "全部课程") Then
            MessageBox.Show("请输入查询条件！", "课程管理系统", MessageBoxButtons.OK, MessageBoxIcon.Information)
            Exit Sub
        End If
        If ComboBox1.Text = "课程号" Then
            stritem = "select 课程号,课程名,院系名 from lessontable, departmenttable where 课程号 like '" & TextBox1.Text & "' and lessontable.院系号=departmenttable.院系号"
        ElseIf ComboBox1.Text = "课程名" Then
            stritem = "select 课程号,课程名,院系名 from lessontable, departmenttable where 课程名 like '%" & TextBox1.Text & "%' and lessontable.院系号=departmenttable.院系号"
        ElseIf ComboBox1.Text = "院系号" Then
            stritem = "select 课程号,课程名,院系名 from lessontable, departmenttable where lessontable.院系号 =" & TextBox1.Text & " and lessontable.院系号=departmenttable.院系号"
        Else
            stritem = "select 课程号,课程名,院系名 from lessontable, departmenttable where lessontable.院系号=departmenttable.院系号"
        End If
        Dim conn As SqlClient.SqlConnection = New SqlClient.SqlConnection("Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\学生管理.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True")
        Dim Cmd As New SqlClient.SqlCommand
        Cmd.Connection = conn
        Cmd.CommandText = stritem
        Dim adapter As SqlClient.SqlDataAdapter = New SqlClient.SqlDataAdapter(Cmd)
        Dim 结果 As New DataTable()
        adapter.Fill(结果)
        Me.DataGridView1.DataSource = 结果
        DataGridView2.DataSource = 结果
        conn.Close()
        conn.Dispose()
    End Sub

可是没有成功，datagridview显示的还是那四列，只不过院系号变为了空，我不知道这是怎么回事，想了很久也没有解决，还请好心的大侠帮我解决啊，先谢了！ --------------------编程问答-------------------- Dim MyCommandBuilder As New SqlCommandBuilder
MyCommandBuilder = New SqlCommandBuilder(sqldataadapter1)
sqldataadapter1.Update(dataset1, "tableA")
dataset1.AcceptChanges()
DataGridView1.Update() --------------------编程问答--------------------

引用 1 楼 wuyq11 的回复:

Dim MyCommandBuilder As New SqlCommandBuilder
MyCommandBuilder = New SqlCommandBuilder(sqldataadapter1)
sqldataadapter1.Update(dataset1, "tableA")
dataset1.AcceptChanges()
DataGridView1.U……

您好，您回我的方法我试了，还是没有用，能加qq，或者邮箱吗，我想仔细解决这个问题，csdn里不能发图，有图的话会更好解释

补充：.NET技术 ,  VB.NET