Message response of ListView column width Change in delphi

Unit Unit1; Interface uses Windows, Messages, sysutils, variants, Classes, Graphics, Controls, Forms, Dialogs, Stdctrls, comctr　
　
Ls,commctrl;　
　Type phd_notify=^hd_notify;　
　　TForm1 = Class (Tform) Listview1:tlistview;　
　　Button1:tbutton;　
　　Procedure Formdestroy (Sender:tobject);　
　Procedure Button1Click (Sender:tobject);　
　　Private {private declarations} Oldproc:twndmethod;　
　Procedure Newproc (var message:tmessage);　
　
Public {public declarations} end;　
　
var Form1:tform1;　
Implementation {$R *.DFM} procedure Tform1.newproc (Var message:tmessage);　
var hn:phd_notify; Begin IF message.　
　　Msg=wm_notify then BEGIN Hn:=phd_notify (Message.lparam); if (hn^.　　 Hdr.code=hdn_begintracka) or (HN^.HDR.CODE=HDN_BEGINTRACKW) THEN BEGIN//Message.result: = 1;　
　　　Join this line so that the column header can not change the width//If you want to handle after the drag is done, you can determine whether hn->hdr.code//equals Hdn_endtracka or HDN_ENDTRACKW, and then do the processing.　
　　ShowMessage (' hehe ');　
　End Else Listview1.dispatch (message);　End　
End　
Procedure Tform1.formdestroy (Sender:tobject);　
Begin Listview1.windowproc:=oldproc;　
　
End　
Procedure Tform1.button1click (Sender:tobject);　
　Begin oldproc:= Listview1.windowproc;　
Listview1.windowproc:= Newproc;　
　
End End.