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scq2099yt 2008-03-25
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WM_COMMAND 一般都是菜单上面的命令消息
The WM_COMMAND message is sent when the user selects a command item from a menu, when a control sends a notification message to its parent window, or when an accelerator keystroke is translated.
A window receives this message through its WindowProc function.
LRESULT CALLBACK WindowProc(
HWND hwnd, // handle to window
WM_COMMAND, // the message to send
WPARAM wParam, // notification code and identifier
LPARAM lParam // handle to control (HWND)
);
Parameters
wParam
The high-order word specifies the notification code if the message is from a control. If the message is from an accelerator, this value is 1. If the message is from a menu, this value is zero.
The low-order word specifies the identifier of the menu item, control, or accelerator.
lParam
Handle to the control sending the message if the message is from a control. Otherwise, this parameter is NULL.
Return Values
If an application processes this message, it should return zero.
wm_notify一般用于自定义的复杂消息，可以传送的信息比wm_command多，一般不会用到wm_notify.
WM_NOTIFY Message
--------------------------------------------------------------------------------
The WM_NOTIFY message is sent by a common control to its parent window when an event has occurred or the control requires some information.
Syntax
To send this message, call the SendMessage function as follows.
lResult = SendMessage( // returns LRESULT in lResult (HWND) hWndControl, // handle to destination control (UINT) WM_NOTIFY, // message ID (WPARAM) wParam, // = (WPARAM) (int) idCtrl; (LPARAM) lParam // = (LPARAM) (LPNMHDR) pnmh; );
Parameters
idCtrl
Identifier of the common control sending the message. This identifier is not guaranteed to be unique. An application should use the hwndFrom or idFrom member of the NMHDR structure (passed as the lParam parameter) to identify the control.
pnmh
Pointer to an NMHDR structure that contains the notification code and additional information. For some notification messages, this parameter points to a larger structure that has the NMHDR structure as its first member.
Return Value
The return value is ignored except for notification messages that specify otherwise.
Remarks
If the message handler is in a dialog box procedure, you must use the SetWindowLong function with DWL_MSGRESULT to set a return value.
The standard Microsoft® Windows® controls (edit controls, combo boxes, list boxes, buttons, scroll bars, and static controls) do not send WM_NOTIFY messages. To determine if a common control will send a WM_NOTIFY message and, if it will, which notification codes it will send, see the documentation for the control.
For Windows 2000 and later systems, the WM_NOTIFY message cannot be sent between processes.
The WM_COMMAND message is sent when the user selects a command item from a menu, when a control sends a notification message to its parent window, or when an accelerator keystroke is translated.
A window receives this message through its WindowProc function.
LRESULT CALLBACK WindowProc(
HWND hwnd, // handle to window
WM_COMMAND, // the message to send
WPARAM wParam, // notification code and identifier
LPARAM lParam // handle to control (HWND)
);
Parameters
wParam
The high-order word specifies the notification code if the message is from a control. If the message is from an accelerator, this value is 1. If the message is from a menu, this value is zero.
The low-order word specifies the identifier of the menu item, control, or accelerator.
lParam
Handle to the control sending the message if the message is from a control. Otherwise, this parameter is NULL.
Return Values
If an application processes this message, it should return zero.
wm_notify一般用于自定义的复杂消息，可以传送的信息比wm_command多，一般不会用到wm_notify.
WM_NOTIFY Message
--------------------------------------------------------------------------------
The WM_NOTIFY message is sent by a common control to its parent window when an event has occurred or the control requires some information.
Syntax
To send this message, call the SendMessage function as follows.
lResult = SendMessage( // returns LRESULT in lResult (HWND) hWndControl, // handle to destination control (UINT) WM_NOTIFY, // message ID (WPARAM) wParam, // = (WPARAM) (int) idCtrl; (LPARAM) lParam // = (LPARAM) (LPNMHDR) pnmh; );
Parameters
idCtrl
Identifier of the common control sending the message. This identifier is not guaranteed to be unique. An application should use the hwndFrom or idFrom member of the NMHDR structure (passed as the lParam parameter) to identify the control.
pnmh
Pointer to an NMHDR structure that contains the notification code and additional information. For some notification messages, this parameter points to a larger structure that has the NMHDR structure as its first member.
Return Value
The return value is ignored except for notification messages that specify otherwise.
Remarks
If the message handler is in a dialog box procedure, you must use the SetWindowLong function with DWL_MSGRESULT to set a return value.
The standard Microsoft® Windows® controls (edit controls, combo boxes, list boxes, buttons, scroll bars, and static controls) do not send WM_NOTIFY messages. To determine if a common control will send a WM_NOTIFY message and, if it will, which notification codes it will send, see the documentation for the control.
For Windows 2000 and later systems, the WM_NOTIFY message cannot be sent between processes.
dianhui 2008-03-25
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对这几个消息的理解要先了解一下Window消息的背景。
在Windows3.1里，控件会将mouse, keybord等等的消息通知它的父窗口， 使用的消息就只有WM_COMMAND, 事件种类和控件ID被包含在wParam中， 控件的句柄包含在lParam中。由于wParam和 lParam已经满了，当控件要向父窗口发送其它特殊消息同时附带很多信息的时候就没有地方可以存放它们了。所以Windows3.1中定义了许多其它的消息种类，比如WM_VSCROLL, WM_CTLCOLOR等等，每种消息wParam,lParam中附带的信息是不同的。
当到了Win32后，控件的种类越来越多，当然不可以为每一个控件都定义一套消息，这样也不利于系统的扩充。所以在Win32中定义了唯一一个强大的消息WM_NOTIFY。当然WM_NOTIFY也遵守原来的消息规则，既只带参数wParam和lParam。唯一不同处在于，此时的lParam中传送的是一个NMHDR指针。不同的控件可以按照规则对NMHDR进行扩充，因此WM_NOTIFY消息传送的信息量可以相当的大，这个可以看看MSDN中的相关说明，TreeControl中就有很多这种消息。
现在就可以知道为什么有ON_MESSAGE ，ON_COMMAND, , ON_NOTIFY了。
ON_MESSAGE是处理所有的Windows的消息的，因为所有的消息都以相同的格式传送，也就是ID, WPARAM, LPARAM.
ON_COMMAND是专门处理WM_COMMAND消息的，这样我们就不用自己解开WM_COMMAND中wParam和lParam中传送的控件ID， 事件种类…，所有的都在MFC内部解决了：），当然方便了。
ON_NOTIFY更是不用说了，看看他的处理函数，是不是把NMHDR解出来了。
这样一样就一目了然了，ON_COMMAND和ON_NOTIFY都可以用ON_MESSAGE来处理，只不过自己要多做很多事情。ON_COMMAND和ON_NOTIFY最好就不要互换了！
在Windows3.1里，控件会将mouse, keybord等等的消息通知它的父窗口， 使用的消息就只有WM_COMMAND, 事件种类和控件ID被包含在wParam中， 控件的句柄包含在lParam中。由于wParam和 lParam已经满了，当控件要向父窗口发送其它特殊消息同时附带很多信息的时候就没有地方可以存放它们了。所以Windows3.1中定义了许多其它的消息种类，比如WM_VSCROLL, WM_CTLCOLOR等等，每种消息wParam,lParam中附带的信息是不同的。
当到了Win32后，控件的种类越来越多，当然不可以为每一个控件都定义一套消息，这样也不利于系统的扩充。所以在Win32中定义了唯一一个强大的消息WM_NOTIFY。当然WM_NOTIFY也遵守原来的消息规则，既只带参数wParam和lParam。唯一不同处在于，此时的lParam中传送的是一个NMHDR指针。不同的控件可以按照规则对NMHDR进行扩充，因此WM_NOTIFY消息传送的信息量可以相当的大，这个可以看看MSDN中的相关说明，TreeControl中就有很多这种消息。
现在就可以知道为什么有ON_MESSAGE ，ON_COMMAND, , ON_NOTIFY了。
ON_MESSAGE是处理所有的Windows的消息的，因为所有的消息都以相同的格式传送，也就是ID, WPARAM, LPARAM.
ON_COMMAND是专门处理WM_COMMAND消息的，这样我们就不用自己解开WM_COMMAND中wParam和lParam中传送的控件ID， 事件种类…，所有的都在MFC内部解决了：），当然方便了。
ON_NOTIFY更是不用说了，看看他的处理函数，是不是把NMHDR解出来了。
这样一样就一目了然了，ON_COMMAND和ON_NOTIFY都可以用ON_MESSAGE来处理，只不过自己要多做很多事情。ON_COMMAND和ON_NOTIFY最好就不要互换了！
txk1452 2008-03-25
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WM_NOTIFY是win9x新控件发送给父窗口的消息，如树型视图、列表视图等
WM_COMMAND是老式控件发送给父窗口的消息，为了向前兼容(windows 3.1)，如Edit等
以上只是从控件方面来说
WM_COMMAND是老式控件发送给父窗口的消息，为了向前兼容(windows 3.1)，如Edit等
以上只是从控件方面来说
wangxipu 2008-03-25
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Contents Index Topic Contents
Previous Topic: Common Control Messages
Next Topic: WM_NOTIFYFORMAT
WM_NOTIFY
WM_NOTIFY
idCtrl = (int) wParam;
pnmh = (LPNMHDR) lParam;
Sent by a common control to its parent window when an event has occurred in the control or the control requires some kind of information.
The return value is ignored except for notification messages that specify otherwise.
idCtrl
Identifier of the common control sending the message. This identifier is not guaranteed to be unique. An application should use the hwndFrom or idFrom member of the NMHDR structure (passed as the lParam parameter) to identify the control.
pnmh
Address of an NMHDR structure that contains the notification code and additional information. For some notification messages, this parameter points to a larger structure that has the NMHDR structure as its first member.
Not all controls will send WM_NOTIFY messages. In particular, the standard Windows controls (edit controls, combo boxes, list boxes, buttons, scroll bars, and static controls) do not send WM_NOTIFY messages. Consult the documentation for the control to determine if it will send any WM_NOTIFY messages and, if it will, which notification codes it will send.
--------------------------------------------------------------------------------
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wangxipu 2008-03-25
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好吧，我查MSDN
WM_COMMAND
The WM_COMMAND message is sent when the user selects a command item from a menu, when a control sends a notification message to its parent window, or when an accelerator keystroke is translated.
WM_COMMAND
wNotifyCode = HIWORD(wParam); // notification code
wID = LOWORD(wParam); // item, control, or accelerator identifier
hwndCtl = (HWND) lParam; // handle of control
Parameters
wNotifyCode
Value of the high-order word of wParam. Specifies the notification code if the message is from a control. If the message is from an accelerator, this parameter is 1. If the message is from a menu, this parameter is 0.
wID
Value of the low-order word of wParam. Specifies the identifier of the menu item, control, or accelerator.
hwndCtl
Value of lParam. Handle to the control sending the message if the message is from a control. Otherwise, this parameter is NULL.
Return Values
If an application processes this message, it should return zero.
Remarks
Accelerator keystrokes that select items from the window menu are translated into WM_SYSCOMMAND messages.
If an accelerator keystroke occurs that corresponds to a menu item when the window that owns the menu is minimized, no WM_COMMAND message is sent. However, if an accelerator keystroke occurs that does not match any of the items in the window's menu or in the window menu, a WM_COMMAND message is sent, even if the window is minimized.
If an application enables a menu separator, the system sends a WM_COMMAND message with the low-word of the wParam parameter set to zero when the user selects the separator.
QuickInfo
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
See Also
Edit Controls Overview, Edit Control Messages, WM_SYSCOMMAND
WM_COMMAND
The WM_COMMAND message is sent when the user selects a command item from a menu, when a control sends a notification message to its parent window, or when an accelerator keystroke is translated.
WM_COMMAND
wNotifyCode = HIWORD(wParam); // notification code
wID = LOWORD(wParam); // item, control, or accelerator identifier
hwndCtl = (HWND) lParam; // handle of control
Parameters
wNotifyCode
Value of the high-order word of wParam. Specifies the notification code if the message is from a control. If the message is from an accelerator, this parameter is 1. If the message is from a menu, this parameter is 0.
wID
Value of the low-order word of wParam. Specifies the identifier of the menu item, control, or accelerator.
hwndCtl
Value of lParam. Handle to the control sending the message if the message is from a control. Otherwise, this parameter is NULL.
Return Values
If an application processes this message, it should return zero.
Remarks
Accelerator keystrokes that select items from the window menu are translated into WM_SYSCOMMAND messages.
If an accelerator keystroke occurs that corresponds to a menu item when the window that owns the menu is minimized, no WM_COMMAND message is sent. However, if an accelerator keystroke occurs that does not match any of the items in the window's menu or in the window menu, a WM_COMMAND message is sent, even if the window is minimized.
If an application enables a menu separator, the system sends a WM_COMMAND message with the low-word of the wParam parameter set to zero when the user selects the separator.
QuickInfo
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
See Also
Edit Controls Overview, Edit Control Messages, WM_SYSCOMMAND
