Help from the Mouse - Win32 Programmer's Reference

Custom Search

Help from the Mouse

Windows provides user access to help information from the mouse by notifying the application whenever the user clicks the right mouse button or clicks a window, control, or menu after clicking the Question (?) button. The application responds by displaying help information associated with the given window, control, or menu.

The system sends a WM_CONTEXTMENU message when the user clicks the right mouse button. The window that was clicked receives the message. If the window is a child window, such as a control, the DefWindowProc function passes the message to the parent window. The WM_CONTEXTMENU message specifies the coordinates of the mouse cursor. The x-coordinate is in the low-order word of the lParam parameter, and the y-coordinate is in the high-order word. If the user clicked a control, the wParam parameter is the handle of the control that received the button click.

The system sends a WM_HELP message when the user clicks an item in a window after clicking the Question (?) button that appears in the title bar of the window. You can add a Question button to a title bar by specifying the WS_EX_CONTEXTHELP style in the CreateWindowEx function when creating the window. The lParam parameter of WM_HELP is a pointer to a HELPINFO structure that contains detailed information about the item for which help is requested, including the coordinates of the mouse cursor at the time the user clicked the mouse button.

The Question button is recommended for use in dialog boxes only. In the past, applications have provided user access to help information about a dialog box by providing a Help button in the dialog box. This method is no longer recommended. Use the Question button instead.

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network