Using DropDown_SelectedIndexChanged to bind gridview, but paging is not working - asp.net

Question

I have a DropDownList which is having few list items. Every time I select any item, based on it I am binding a gridview, hence resulting gridview depends on my selection. Some results are exceeding the pagesize hence I need to navigate on 2nd page in GridView, however the GridView is disappeating when I am selecting 2nd page.
protected void DDL_SelectedIndexChanged(object sender, EventArgs e)
{
string constr = ConfigurationSettings.AppSettings["ConnectionInfo"];
SqlConnection con = new SqlConnection(constr);
con.Open();
string str = string.Empty;
str = "SELECT * FROM Table1";
SqlDataAdapter adp = new SqlDataAdapter(str, con);
DataSet ds = new DataSet();
adp.Fill(ds, "myds");
BusinessKPIGrid.DataSource = ds;
BusinessKPIGrid.DataBind();
}
protected void OnGridViewPaging(object sender, GridViewPageEventArgs e)
{
//I know I need to bind the gridview here, but how ?
BusinessKPIGrid.PageIndex = e.NewPageIndex;
BusinessKPIGrid.DataBind();
}
I don't know how to bind the gridview in paging event, since I do not have any separate binding function.

Answer 1

there is a separate function for page event for grid view..create separate method for binding grid & call that method on pageindexchange event..
protected void BusinessKPIGrid_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
BusinessKPIGrid.PageIndex = e.NewPageIndex;
bindyourgrid();
}

Answer 2

try this
protected void DDL_SelectedIndexChanged(object sender, EventArgs e)
{
string constr = ConfigurationSettings.AppSettings["ConnectionInfo"];
SqlConnection con = new SqlConnection(constr);
con.Open();
string str = string.Empty;
str = "SELECT * FROM Table1";
SqlDataAdapter adp = new SqlDataAdapter(str, con);
DataSet ds = new DataSet();
adp.Fill(ds, "myds");
ViewState["ds"]=ds;
BusinessKPIGrid.DataSource = ds;
BusinessKPIGrid.DataBind();
}
protected void OnGridViewPaging(object sender, GridViewPageEventArgs e)
{
//I know I need to bind the gridview here, but how ?
BusinessKPIGrid.PageIndex = e.NewPageIndex;
BusinessKPIGrid.DataSource = (DataSet)ViewState["ds"];
BusinessKPIGrid.DataBind();
}

Answer 3

From DDL_SelectedIndexChanged if you are searching some thing then use 'PageIndexChanging' and set the page size for it
protected void gvworker_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
gvworker.PageIndex = e.NewPageIndex;
//result got from ddl list i.e bind your data set
}