Can't drag or resize custom frame window - c

Question

I'm programming an application that has a window that has custom frame.
I visited these sites and use them both to create my own app:
Winprog
And also:
Microsoft Docs: Custom frame window using dwm
I use TDM_GCC and c language to write this app.
This app compiled using some linkers successfully; but my custom frame window is undraggable and non-resizable.
Please help me to resolve my problem.
My codes are below:
#include <windows.h>
#include <windowsx.h>
#include <winuser.h>
#include <dwmapi.h>
#include <stdbool.h>
const char g_szClassName[] = "myWindowClass";
LRESULT HitTestNCA(HWND hWnd, WPARAM wParam, LPARAM lParam)
{
POINT ptMouse = { GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam)};
RECT rcWindow;
GetWindowRect(hWnd, &rcWindow);
RECT rcFrame = { 0 };
AdjustWindowRectEx(&rcFrame, WS_OVERLAPPEDWINDOW & ~WS_CAPTION, false, WS_EX_CLIENTEDGE);
USHORT uRow = 1;
USHORT uCol = 1;
bool fOnResizeBorder = false;
if (ptMouse.y >= rcWindow.top && ptMouse.y < rcWindow.top + 50)
{
fOnResizeBorder = (ptMouse.y < (rcWindow.top - rcFrame.top));
uRow = 0;
}
else if (ptMouse.y < rcWindow.bottom && ptMouse.y >= rcWindow.bottom - 50)
{
uRow = 2;
}
if (ptMouse.x >= rcWindow.left && ptMouse.x < rcWindow.left + 50)
{
uCol = 0; // left side
}
else if (ptMouse.x < rcWindow.right && ptMouse.x >= rcWindow.right - 50)
{
uCol = 2; // right side
}
LRESULT hitTests[3][3] =
{
{ HTTOPLEFT, fOnResizeBorder ? HTTOP : HTCAPTION, HTTOPRIGHT },
{ HTLEFT, HTNOWHERE, HTRIGHT },
{ HTBOTTOMLEFT, HTBOTTOM, HTBOTTOMRIGHT },
};
return hitTests[uRow][uCol];
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
MARGINS m = {50,50,50,50};
bool f = false;
LRESULT l = 0;
HRESULT hr = S_OK;
RECT rcClient;
if(msg == WM_ACTIVATE){
hr = DwmExtendFrameIntoClientArea(hwnd, &m);
f = true;
l = 0;
}
if(msg == WM_NCCALCSIZE){
wParam = true;
return 0;
}
if(msg == WM_CREATE){
GetWindowRect(hwnd, &rcClient);
SetWindowPos(hwnd,
NULL,
rcClient.left, rcClient.top,
800, 600,
SWP_FRAMECHANGED);
f = true;
l = 0;
}
if ((msg == WM_NCHITTEST) && (l == 0)){
l = HitTestNCA(hwnd, wParam, lParam);
if (l != HTNOWHERE)
f = false;
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(NULL_PEN);
wc.lpszMenuName = NULL;
wc.lpszClassName = g_szClassName;
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
if(!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
hwnd = CreateWindowEx(
WS_EX_CLIENTEDGE ,
g_szClassName,
"The title of my window",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT, 800, 600,
NULL, NULL, hInstance, NULL);
if(hwnd == NULL)
{
MessageBox(NULL, "Window Creation Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
// Step 3: The Message Loop
while(GetMessage(&Msg, NULL, 0, 0) > 0)
{
TranslateMessage(&Msg);
DispatchMessage(&Msg);
}
return Msg.wParam;
}
And my project is here in a zip file:
a.zip