如何得到窗口最小化或最大化时的消息！

[傻乐tao]

如：当单击最小化按钮或关闭按钮时可以让窗口隐长缩在托盘中，而并非最小化或关闭，如何去做！

[「已注销」]

在窗体的OnResize事件中判断WindowState就可以了

@_@

[傻乐tao]

如果是关闭窗口呢！

[wjzhuang]

Form::OnClose()

[傻乐tao]

我的意思是说可以拦截窗口被关闭时的消息吗？
比如说当点击了关闭窗口的 × 以后，我不让程序关闭，而让他在托盘中！
拜托了！

[傻乐tao]

猪兄，在吗？

[Chxis]

在Form::OnCloseQuery()中,把CanClose设为false;

[wjzhuang]

自己做消息处理,贴一篇文章你看看
Q: Customize the system menu of a form

Answer
Before you attempt to modify the system menu of your program, you might want to ask yourself why you want to do this. Modifying the system menu of a program is not a standard practice. While testing the code for this FAQ, I ran various programs on my computer to see which programs customize their system menus. None of the following programs modify their system menus: RegEdit, Explorer, Word, Excel, Outlook, MS Dev Studio, Internet Explorer, Netscape 4.0, the Windows Calc program, BC++ 5, C++Builder, Delphi, MS Paint, Notepad, MS Hearts, Laplink, MSDN InfoViewer, and InstallShield. In fact, I could only find two programs that did modify the system menu: the character map utility, and the window that surrounds a DOS box. If you feel that modifying the system menu makes sense in your program, then read through the following set of steps.

Step 1: Modifying the system menu requires that you use direct API calls. The VCL does not encapsulate the system menu (although you might be able to find a freeware control for the system menu). Use the GetSystemMenu API function to obtain a menu handle to the system menu. Then use the API functions to add or delete your menu items. This code modifies the system menu of the main form at startup.

#define IDS_CUSTOMID 0x1000 // menu ID

__fastcall TForm1::TForm1(TComponent* Owner)
: TForm(Owner)
{
const AnsiString MenuString = "Custom Menu";
MENUITEMINFO info = { sizeof(MENUITEMINFO),
MIIM_TYPE | MIIM_STATE | MIIM_ID ,
MFT_STRING, // menu type is string
MFS_ENABLED, // menu item is enabled
IDS_CUSTOMID, // id of menu item
NULL, // no sub menu
NULL, // no check bitmap
NULL, // no uncheck bitmap
0, // no item data
MenuString.c_str(), // string of menu item
0}; // last item not used


// obtain the menu handle for the system menu
HMENU SysMenu = GetSystemMenu(Handle, FALSE);

// Insert the new menu item just after the close menu item. If the TRUE
InsertMenuItem (SysMenu, SC_CLOSE, TRUE, &info);
}

Step 2: Now you need to add code that will respond to the message that is sent when the user selects the new menu item from the system menu. Add a message map and a function prototype to the include file of your form. Then code the function body in the source file.

//-------------------------------------------------------------
// Inside the header file
//
class TForm1 : public TForm
{
__published: // IDE-managed Components
private: // User declarations
void __fastcall WMSysCommand(TWMSysCommand &Msg);
public: // User declarations
__fastcall TForm1(TComponent* Owner);

BEGIN_MESSAGE_MAP
MESSAGE_HANDLER(WM_SYSCOMMAND,TWMSysCommand,WMSysCommand)
END_MESSAGE_MAP(TForm)
};
//-------------------------------------------------------------


//-------------------------------------------------------------
// Inside the CPP file
//
void __fastcall TForm1::WMSysCommand(TWMSysCommand &Msg)
{
if( Msg.CmdType == IDS_CUSTOMID)
{
Width -=5;
Height -=5;
Msg.Result = true;
}
else
TForm::Dispatch(&Msg);
}

Note: When you add menu items to the system menu, use menu IDs that are lower than 0xF000 to avoid conflicting with the IDs of the default system menu items.

Note: Once you obtain the HMENU handle to the system menu, you can use that handle to call any of the API menu functions. These include DeleteMenu, SetMenuItemInfo, and the functions that check, highlight, and put bitmaps on menu items.

Note: Menu items from the main menu of your program send WM_COMMAND messages to your window when the user selects an item. The system menu sends WM_SYSCOMMAND messages.

Note: The wParam parameter of the WM_SYSCOMMAND message contains the menu ID for the item that was clicked. The TWMSysCommand message structure maps wParam to the CmdType structure item.

Note: The system menu will initially contain the default system menu items for a form. These include minimize and close commands. These commands have built in IDs (SC_CLOSE, SC_MINIMIZE, etc). Normally, you will want to pass messages for the default system menu items on to the default handler. The default items will not function if you forget to pass the message on. If you want to intercept on of the default menu handlers, you will need to mask off the lower for bits of the CmdType parameter. According to the MSDN documentation, the last 4 bits in the wParam parameter in a WM_SYSCOMMAND message are reserved for internal use. This applies only to the default system menu items that are created by windows. You don't need to mask CmdType when handling commands sent by items that you have added to the menu. Here is a modified version of the handler to show what I mean:

void __fastcall TForm1::WMSysCommand(TWMSysCommand &Msg)
{
if( Msg.CmdType == IDS_CUSTOMID)
{
Width -=5;
Height -=5;
Msg.Result = true;
}
else if ( (Msg.CmdType & 0xFFF0) == SC_CLOSE)
Application->MessageBox("I don't want to close.","test",MB_OK);
else
TForm::Dispatch(&Msg);
}

Note: The technique above works, but keep in mind that the minimize, restore, and close push buttons on the title bar of a program also send WM_SYSCOMMAND messages. Intercepting the SC_CLOSE command from the system menu also prevents the user from closing the program via the close button.

Note: The system menu for the hidden application window is different from the system menu for a form. This plays a role when the user activates the system menu of the application while the application is minimzed. When the user brings up the system menu by right clicking on the program's taskbar icon, the system menu of the application window will appear, which differs from the system menu of a form.

[傻乐tao]

倒！
E文好痛苦！
叶秋枫 说的ＯnSize 事件，当窗口最小化时，不能激发此事件！