GridView paging not working proper

Question

I'm trying to make paging with GridView,
and I have already added GridView's PageIndexChanging method,
but the second page returns an empty page.
What I'm doing wrong with this code ?

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    GridView1.DataBind();
}

Answer 1

This problem has solved when I added this

private void FillGrid()
{
    GridView1.DataSource = "Query..."
    GridView1.DataBind();
}

And changed :

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    FillGrid();
}