How to findcontrols on gridview RowCreated,RowDataBound,RowUpdating,RowDeleting,RowEditing and RowCommand?

protected void Gridview1_RowCreated(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                LinkButton lnkFile = (LinkButton)e.Row.FindControl("lnkFilePath");
                if (lnkFile != null)
                    ScriptManager.GetCurrent(this.Page).RegisterPostBackControl(lnkFile);
            }
        }

protected void Gridview1_RowDataBound(object sender, GridViewRowEventArgs e)
        {            
                if (e.Row.RowType == DataControlRowType.DataRow)
                {
                    ImageButton btnDelete = (ImageButton)e.Row.FindControl("btnDelete");
                    if (btnDelete != null)
                        btnDelete.Attributes.Add("onclick", "javascript:return  confirm('Are you sure you want to delete this record?');");
  }
 }

protected void Gridview1_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {            
                GridViewRow row = Gridview1.Rows[e.RowIndex];             
                TextBox txtDesc = (TextBox)row.Cells[0].FindControl("txtListValue");              
 }

protected void Gridview1_RowDeleting(object sender, GridViewDeleteEventArgs e)
        {
         Label lblListDesc = (Label)Gridview1.Rows[e.RowIndex].FindControl("lblListValue");
 }

protected void Gridview1_RowEditing(object sender, GridViewEditEventArgs e)
        {            
                Label lblIsActive = (Label)(Gridview1.Rows[Gridview1.EditIndex].FindControl("lblStatus"));
 }

protected void Gridview1_RowCommand(object sender, GridViewCommandEventArgs e)
        {            
                GridViewRow grow = (GridViewRow)((Control)e.CommandSource).NamingContainer;                   
  Label lblTemp = (Label)grow.FindControl("lblDatatype");
 }