Advanced MFC Programming

Chapter 1. Tool Bar and Dialog Bar
{
}
TRACE0("Failed to create status bar\n");
return -1;
}
m_wndToolBar.SetBarStyle(m_wndToolBar.GetBarStyle() |
CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC);
m_wndToolBar.EnableDocking(CBRS_ALIGN_ANY);
m_wndColorButton.SetBarStyle(m_wndColorButton.GetBarStyle() |
CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC);
m_wndColorButton.EnableDocking(CBRS_ALIGN_ANY);
EnableDocking(CBRS_ALIGN_ANY);
DockControlBar(&m_wndToolBar);
DockControlBar(&m_wndColorButton);
return 0;
By compiling and executing the sample application at this point, we can see that the tool bar has been
created. The tool bar can be docked to one of the four borders of the mainframe window or be floated. If we
dock the tool bar to either left or right border, we will see that the tool bar will automatically have a vertical
layout. This feature is supported by class CToolBar, we don’t need to add any line of code in order to have
it.
Command Message Mapping
The new tool bar looks very disappointing. Although we made much effort to add it, none of its
buttons can be used to execute command. This is because we still haven’t implemented any message
handler for the new commands, therefore the buttons will be disabled all the time.
In Windows applications, commands are executed through sending WM_COMMAND message. As the user
clicks a menu command or a tool bar button, the system will send a WM_COMMAND message to the application.
All the Windows messages have two parameters, WPARAM and LPARAM (They are nothing but two integers,
as an application receives a message, it will also receive the message parameters). For WM_COMMAND
message, its WPARAM parameter is used to store the control ID (Command ID, such as ID_BUTTON_RED in
our samples), which can be examined by the application to make appropriate response.
In a general Windows application, message is received and processed by a callback function. When
an application is initialized, it stores the address of the callback function in the system. When a message is
generated, the system uses this address to call the callback function and pass the message as well as the
associated parameters to the application. Besides processing the message, the application can also choose to
pass the message to other applications in the system.
If an application has callback function, we can process message WM_COMMAND within it. A general
callback function for this purpose looks like the following:
……
……
LONG APIENTRY CallBackProc
(
HWND hwnd,
UINT message,
DWORD wParam,
LONG lParam)
{
switch (message)
{
case WM_CREATE:
{
break;
}
case WM_COMMAND:
{
switch(wParam)
{
case ID_BUTTON_RED:
{
}
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