declaring gridview selectcommand

When the page loads, the GridView (located in an update panel) should be loaded with my first SQL SELECT statement.

On the button click, the same GridView will be loaded with new data.

What am i doing wrong? On startup, the GridView doesn't appear.

Public cmd As New SqlCommand()
    Public percentp As New SqlCommand()
    Public da As New SqlDataAdapter(cmd)
    Public conn As New SqlConnection("Data Source=TEST-TEST-TEST01;Initial Catalog=TEST;Integrated Security=True")

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    cmd.Connection = conn
    conn.Open()
    Dim ds As New DataSet
    cmd.CommandText = "Select * from test1"
    da.Fill(ds)
    GridView1.DataSource = ds.Tables(0)
    da.FillSchema(ds, SchemaType.Mapped)
    conn.Close()        
End Sub   

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
    cmd.Connection = conn
    conn.Open()
    Dim ds As New DataSet
    cmd.CommandText = "SELECT * from test"
    da.Fill(ds)
    GridView1.DataSource = ds.Tables(0)
    da.FillSchema(ds, SchemaType.Mapped)
    conn.Close()        
    TextBox1.Text="aaaaaaaaaaa"
End Sub
End Class

I tried GridView1.DataS开发者_如何学Goource = ds.Tables(0) GridView1.DataBind

You need to call

GridView1.DataSource = ds.Tables(0)
GridView1.DataBind() // this is needed to bind the datasource to GridView

You need to call GridView1.DataBind(); after setting the data source.

You have forgotten to include the GridView1.Databind() command after you retrieve your data from the database. You typically set your data source after you retrieve your data, so your Page_Load method would work better like this:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    cmd.Connection = conn
    conn.Open()
    Dim ds As New DataSet
    cmd.CommandText = "Select * from test1"
    da.Fill(ds)
    conn.Close()        
    GridView1.DataSource = ds.Tables(0)
    GridView1.DataBind()        
End Sub