Bir Windows API programında kullanılan Button kontrolünü kendi belirlediğimiz görünümlere göre çizmek için Subclassing işlemi ile Button için oluşturduğumuz fonksiyon içinde WM_PAINT mesajını kullanabiliriz.
Programda yer alacak main.c, resource.rc ve manifest.xml dosyalarının içeriği aşağıdaki şekilde olacaktır:
main.c
#if defined(UNICODE) && !defined(_UNICODE)
#define _UNICODE
#elif defined(_UNICODE) && !defined(UNICODE)
#define UNICODE
#endif
#define _WIN32_WINNT 0x0501
#define _WIN32_IE 0x0501
#include <tchar.h>
#include <windows.h>
#include <commctrl.h>
#define IDC_BUTTON 1001
/* Declare Windows procedure */
LRESULT CALLBACK WindowProcedure(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK ButtonProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
/* Make the class name into a global variable */
TCHAR szClassName[ ] = _T("CodeBlocksWindowsApp");
HWND hwndButton;
int WINAPI WinMain(HINSTANCE hThisInstance,
HINSTANCE hPrevInstance,
LPSTR lpszArgument,
int nCmdShow)
{
HWND hwnd; /* This is the handle for our window */
MSG messages; /* Here messages to the application are saved */
WNDCLASSEX wincl; /* Data structure for the windowclass */
/* The Window structure */
wincl.hInstance = hThisInstance;
wincl.lpszClassName = szClassName;
wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */
wincl.style = CS_DBLCLKS; /* Catch double-clicks */
wincl.cbSize = sizeof (WNDCLASSEX);
/* Use default icon and mouse-pointer */
wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
wincl.lpszMenuName = NULL; /* No menu */
wincl.cbClsExtra = 0; /* No extra bytes after the window class */
wincl.cbWndExtra = 0; /* structure or the window instance */
/* Use Windows's default colour as the background of the window */
wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
/* Register the window class, and if it fails quit the program */
if (!RegisterClassEx (&wincl)) return 0;
/* The class is registered, let's create the program*/
hwnd = CreateWindowEx (
0, /* Extended possibilites for variation */
szClassName, /* Classname */
_T("Subclassing Button"), /* Title Text */
WS_OVERLAPPEDWINDOW, /* default window */
CW_USEDEFAULT, /* Windows decides the position */
CW_USEDEFAULT, /* where the window ends up on the screen */
400, /* The programs width */
300, /* and height in pixels */
HWND_DESKTOP, /* The window is a child-window to desktop */
NULL, /* No menu */
hThisInstance, /* Program Instance handler */
NULL /* No Window Creation data */
);
/* Make the window visible on the screen */
ShowWindow (hwnd, nCmdShow);
/* Run the message loop. It will run until GetMessage() returns 0 */
while (GetMessage (&messages, NULL, 0, 0))
{
/* Translate virtual-key messages into character messages */
TranslateMessage(&messages);
/* Send message to WindowProcedure */
DispatchMessage(&messages);
}
/* The program return-value is 0 - The value that PostQuitMessage() gave */
return messages.wParam;
}
/* This function is called by the Windows function DispatchMessage() */
LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message) /* handle the messages */
{
case WM_CREATE:
{
// Subclassed buton ve WM_PAINT yöntemi
hwndButton = CreateWindowEx(0, "BUTTON", "Button",
WS_CHILD | WS_VISIBLE, 20, 20, 120, 25,
hwnd, (HMENU) IDC_BUTTON, NULL, NULL);
SetWindowSubclass(hwndButton, ButtonProc, 0, 0);
}
break;
case WM_COMMAND:
{
if (HIWORD(wParam) == BN_CLICKED) {
switch(LOWORD(wParam)) {
case IDC_BUTTON:
MessageBox(NULL, "Button01 tıklandı.", "Buton tıklama", MB_OK);
break;
}
}
}
break;
case WM_DESTROY:
PostQuitMessage (0); /* send a WM_QUIT to the message queue */
break;
default: /* for messages that we don't deal with */
return DefWindowProc (hwnd, message, wParam, lParam);
}
return 0;
}
LRESULT CALLBACK ButtonProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
switch (message) {
case WM_PAINT:
{
if (hwnd==hwndButton) {
PAINTSTRUCT ps;
BeginPaint(hwnd, &ps);
SetTextColor(ps.hdc, RGB(236, 236, 236));
SetBkMode(ps.hdc, TRANSPARENT);
FillRect(ps.hdc, &ps.rcPaint, (HBRUSH)CreateSolidBrush(RGB(230, 30, 90)));
DrawText(ps.hdc, "Button01", -1, &ps.rcPaint, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
EndPaint(hwnd, &ps);
return 0; // Sistem Button sınıf penceresinin işlem yapmaması için
}
}
break;
}
return DefSubclassProc(hwnd, message, wParam, lParam);
}
resource.rc
1 24 "manifest.xml"
manifest.xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity version="1.0.0.0" processorArchitecture="*" name="CompanyName.ProductName.YourApplication" type="win32" />
<description>Your application description here.</description>
<dependency>
<dependentAssembly>
<assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*" />
</dependentAssembly>
</dependency>
</assembly>
Program derleyip çalıştırdığımızda aşağıdakine benzer bir ekran görüntüsü karşımıza gelecektir: