Row Command Get controls in Gridview asp.net C#

How we use row command in C# of Gridview.

protected void GridView1_RowCommand(Object sender, GridViewCommandEventArgs e)
{            
    if (e.CommandName == "Yes")
    {           
        GridViewRow gvRow = (GridViewRow)(((LinkButton)e.CommandSource).NamingContainer);
        int RowIndex = gvRow.RowIndex;            
        Int32 iAppID = Convert.ToInt32(GridView1.DataKeys[gvRow.RowIndex].Value.ToString()); 

}