How to get rowindex, ControlsSelectedIndexChanging in Gridview Event

RowCommand Event:

 1.  GridViewRow grv = ((GridViewRow)((DataControlFieldCell)((LinkButton)e.CommandSource).Parent).Parent);

Using NaingContainer

2.  GridViewRow row = (GridViewRow)((LinkButton)e.CommandSource).NamingContainer;

int rowIndex = row .RowIndex;

RowDeleting, RowUpdating Event:

int UserID = Convert.ToInt32(GridUser.DataKeys[e.RowIndex].Values["txtUserID"]); //DataKey

TextBox txtUserName = (TextBox)GridUser.Rows[e.RowIndex].FindControl("txtUserName");

SelectedIndexChanging Event:

Label name = (Label)GridUser.Rows[e.NewSelectedIndex].FindControl("lblUserName");

OnRowDataBound:
if (e.Row.RowType == DataControlRowType.DataRow)
{
Label lblName = (Label)e.Row.FindControl("lblName");
}

DropDown Selected Index Changed, TextBox Changed Event:

 DropDownList ddl = (DropDownList)sender;
                GridViewRow row = (GridViewRow)ddl.Parent.Parent;
                int idx = row.RowIndex;

                DropDownList ddlCountry= (DropDownList)row.FindControl("ddlCountry");

Button Click Event:

TextBox txtuser = (TextBox)GridUser.FooterRow.FindControl("txtNewUserName");