SetWindowLong和GetWindowLong的用法，哪位大侠帮一下呀！！！－－100分 ( 积分: 100 )

unit Unit1;<br><br>interface<br><br>uses<br> &nbsp;Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,<br> &nbsp;Dialogs, StdCtrls;<br><br>type<br> &nbsp;TForm1 = class(TForm)<br> &nbsp; &nbsp;Memo1: TMemo;<br> &nbsp; &nbsp;procedure FormCreate(Sender: TObject);<br> &nbsp;private<br> &nbsp;<br> &nbsp;public<br> &nbsp; &nbsp;{ Public declarations }<br> &nbsp;end;<br> &nbsp;Function ClientWindowProc( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br> &nbsp;Function ClientWindowProc11( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>var<br> &nbsp;Form1: TForm1;<br><br>implementation<br><br>{$R *.dfm}<br><br>Function ClientWindowProc( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>Var<br> &nbsp;pUserdata: Pointer;<br>Begin<br> &nbsp;pUserdata:= Pointer( GetWindowLong( wnd, GWL_USERDATA ));<br> &nbsp;Case msg of<br> &nbsp; &nbsp;WM_MOUSEWHEEL:<br> &nbsp; &nbsp; &nbsp; &nbsp;begin<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;ShowMessage('WM_MOUSEWHEEL');<br> &nbsp; &nbsp; &nbsp; &nbsp;End;<br> &nbsp;Result := CallWindowProc(pUserdata, wnd, msg, wparam, lparam );<br>end;<br><br>Function ClientWindowProc11( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>Var<br> &nbsp;pUserdata: Pointer;<br>Begin<br> &nbsp;pUserdata:= Pointer( GetWindowLong( wnd, GWL_USERDATA ));<br> &nbsp;Case msg of<br> &nbsp; &nbsp;WM_RBUTTONDOWN:begin<br> &nbsp; &nbsp; &nbsp;showmessage('WM_RBUTTONDOWN');<br> &nbsp; &nbsp;end;<br> &nbsp;End;<br> &nbsp;Result := CallWindowProc(pUserdata, wnd, msg, wparam, lparam );<br>end;<br><br>procedure TForm1.FormCreate(Sender: TObject);<br>begin<br>　//为什么同一个控件不能用两次？<br> &nbsp;SetWindowLong(Memo1.Handle, GWL_USERDATA, SetWindowLong(Memo1.Handle, GWL_WNDPROC, integer( @ClientWindowProc)));<br> &nbsp;SetWindowLong(Memo1.Handle, GWL_USERDATA, SetWindowLong(Memo1.Handle, GWL_WNDPROC, integer( @ClientWindowProc11)));<br>end;<br><br>end.

unit Unit1;<br><br>interface<br><br>uses<br> &nbsp;Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,<br> &nbsp;Dialogs, StdCtrls;<br><br>type<br> &nbsp;TForm1 = class(TForm)<br> &nbsp; &nbsp;Memo1: TMemo;<br> &nbsp; &nbsp;procedure FormCreate(Sender: TObject);<br> &nbsp;private<br> &nbsp;<br> &nbsp;public<br> &nbsp; &nbsp;{ Public declarations }<br> &nbsp;end;<br> &nbsp;Function ClientWindowProc( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br> &nbsp;Function ClientWindowProc11( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>var<br> &nbsp;Form1: TForm1;<br><br>implementation<br><br>{$R *.dfm}<br><br>Function ClientWindowProc( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>Var<br> &nbsp;pUserdata: Pointer;<br>Begin<br> &nbsp;pUserdata:= Pointer( GetWindowLong( wnd, GWL_USERDATA ));<br> &nbsp;Case msg of<br> &nbsp; &nbsp;WM_MOUSEWHEEL:<br> &nbsp; &nbsp; &nbsp; &nbsp;begin<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;ShowMessage('WM_MOUSEWHEEL');<br> &nbsp; &nbsp; &nbsp; &nbsp;End;<br> &nbsp;Result := CallWindowProc(pUserdata, wnd, msg, wparam, lparam );<br>end;<br><br>Function ClientWindowProc11( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>Var<br> &nbsp;pUserdata: Pointer;<br>Begin<br> &nbsp;pUserdata:= Pointer( GetWindowLong( wnd, GWL_USERDATA ));<br> &nbsp;Case msg of<br> &nbsp; &nbsp;WM_RBUTTONDOWN:begin<br> &nbsp; &nbsp; &nbsp;showmessage('WM_RBUTTONDOWN');<br> &nbsp; &nbsp;end;<br> &nbsp;End;<br> &nbsp;Result := CallWindowProc(pUserdata, wnd, msg, wparam, lparam );<br>end;<br><br>procedure TForm1.FormCreate(Sender: TObject);<br>begin<br>　//为什么同一个控件不能用两次？<br> &nbsp;SetWindowLong(Memo1.Handle, GWL_USERDATA, SetWindowLong(Memo1.Handle, GWL_WNDPROC, integer( @ClientWindowProc)));<br> &nbsp;SetWindowLong(Memo1.Handle, GWL_USERDATA, SetWindowLong(Memo1.Handle, GWL_WNDPROC, integer( @ClientWindowProc11)));<br>end;<br><br>end.

老兄， GWL_USERDATA标志只能保存一个32位变量吧 ？

To:刘麻子<br>　　谢谢指导，那请问刘兄，如果要实现上述功能应怎么做呀？

可以增加类额外空间或者窗口实例额外空间的大小，<br>把我们自己的数据写在最后面而不影响原类，<br>具体请看这本书里关于子类化/超类化相关章节，<br>http://www.2ccc.com/article.asp?articleid=2063

谢谢刘兄，先看看再说

执行两次造成的消息处理死循环

ClientWindowProc11调用ClientWindowProc-调用ClientWindowProc11造成死循环

To:ffhello<br> &nbsp;那如何对其进行改进呢

setwindowlong前先判断<br>pUserdata:= Pointer( GetWindowLong( wnd, GWL_USERDATA ));的值是不是&gt;0

To:刘麻子<br>　　大哥，具体是哪一章呀

To:ffhello<br> &nbsp;如果在SetWindowLong前判断一下，那就不能执行两次SetWindowLong了

pUserdata:= Pointer( GetWindowLong( dd, GWL_USERDATA ));<br>pwinlong:=GetWindowLong(dd, GWL_wndproc ));<br>if(puserdata&lt;&gt;pwinlong)then//判断是否已经setwindowlong了<br> SetWindowLong(dd.Handle, GWL_USERDATA, SetWindowLong(dd.Handle, GWL_WNDPROC, integer( @ClientWindowProc)));

To:ffhello<br> &nbsp;不行呀

应该没问题，你把代码贴上来看看

unit Unit1;<br><br>interface<br><br>uses<br> &nbsp;Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,<br> &nbsp;Dialogs, StdCtrls;<br><br>type<br> &nbsp;TForm1 = class(TForm)<br> &nbsp; &nbsp;Memo1: TMemo;<br> &nbsp; &nbsp;procedure FormCreate(Sender: TObject);<br> &nbsp;private<br> &nbsp;<br> &nbsp;public<br> &nbsp; &nbsp;{ Public declarations }<br> &nbsp;end;<br> &nbsp;Function ClientWindowProc( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br> &nbsp;Function ClientWindowProc11( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>var<br> &nbsp;Form1: TForm1;<br><br>implementation<br><br>{$R *.dfm}<br><br>Function ClientWindowProc( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>Var<br> &nbsp;pUserdata: Pointer;<br>Begin<br> &nbsp;pUserdata:= Pointer( GetWindowLong( wnd, GWL_USERDATA ));<br> &nbsp;Case msg of<br> &nbsp; &nbsp;WM_MOUSEWHEEL:<br> &nbsp; &nbsp; &nbsp; &nbsp;begin<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;ShowMessage('WM_MOUSEWHEEL');<br> &nbsp; &nbsp; &nbsp; &nbsp;End;<br> &nbsp;Result := CallWindowProc(pUserdata, wnd, msg, wparam, lparam );<br>end;<br><br>Function ClientWindowProc11( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;<br>Var<br> &nbsp;pUserdata: Pointer;<br>Begin<br> &nbsp;pUserdata:= Pointer( GetWindowLong( wnd, GWL_USERDATA ));<br> &nbsp;Case msg of<br> &nbsp; &nbsp;WM_RBUTTONDOWN:begin<br> &nbsp; &nbsp; &nbsp;showmessage('WM_RBUTTONDOWN');<br> &nbsp; &nbsp;end;<br> &nbsp;End;<br> &nbsp;Result := CallWindowProc(pUserdata, wnd, msg, wparam, lparam );<br>end;<br><br>procedure TForm1.FormCreate(Sender: TObject);<br>var<br> &nbsp;pUserdataointer;<br> &nbsp;pwinlong:integer;<br>begin<br> &nbsp;SetWindowLong(ScrollBox1.Handle, GWL_USERDATA, SetWindowLong(ScrollBox1.Handle, GWL_WNDPROC, integer( @ClientWindowProc)));<br> &nbsp;pUserdata:= Pointer( GetWindowLong( Memo1.Handle, GWL_USERDATA ));<br> &nbsp;pwinlong:=GetWindowLong(Memo1.Handle, GWL_wndproc );<br> &nbsp;if(integer(puserdata)&lt;&gt;pwinlong) then//判断是否已经setwindowlong了<br> &nbsp; SetWindowLong(Memo1.Handle, GWL_USERDATA, SetWindowLong(Memo1.Handle, GWL_WNDPROC, integer( @ClientWindowProc11)));<br><br>end;<br><br>end.

最简单的方法，分别用两个变量保存原函数地址。

To:刘兄<br>我还是想学学“可以增加类额外空间或者窗口实例额外空间的大小，<br>把我们自己的数据写在最后面而不影响原类，<br>”,能不能麻烦刘兄给小弟讲解一二呀，谢谢了！

请看“第５章 Window Subclassing 和 Window Superclassing”。