C / C++ / MFC

{
  "city_data":[
     {
       "t":"m",
       "l":[12.0,10.3,0.0,1.0]
     },
     {
       "t":"l",
       "l":[10.1,20.37,0.0,1.0]
     },
     {
       "t":"l",
       "l":[47.82,4.63,0.0,1.0]
     },
     {
       "t":"m",
       "l":[67.66,43.33,0.0,1.0]
     }
   ],
   "map_data":"JZDKZTCaTyWQymUwmk8lkMplMJpPJZDKZTCaTyWQymUwmk/8/+n8AVAZ1WCxk8rYAAAAASUVORK5CYII="
}

std::ifstream f(file);
json data = json::parse(f);

json& cityInfo = data["city_data"];
for (unsigned int i = 0; i < cityInfo.size(); i++)
        {
            json& cityType = cityInfo[i];
            std::string ctyTyp = cityType["t"];
            json& cityLoc = cityType["l"];
            std::float_t x = cityLoc[0];
            std::float_t y = cityLoc[1];
            // do something with the retrieved values      
        }
//To retreive map data
ofstream outfile;
outfile.open(m_strFolderPath + m_strFileName + ".png", ofstream::binary);
std::string mapFrame = data["map_data"];
string temp = base64_decode(mapFrame );
outfile.write(temp.c_str(), temp.size());
outfile.close();
f.close();

/// Application arguments.
struct ApplicationArguments {};

/// <summary>
/// Application arguments.
/// </summary>
struct ApplicationArguments {};

int WINAPI WinMain(HINSTANCE hinstExe, HINSTANCE hinstPrev, LPSTR pszCmdLine, int nCmdShow)
{


DialogBox(hinstExe, MAKEINTRESOURCE(IDD_DIRWALK), NULL, Dlg_Proc);

return(0);
}

BOOL CALLBACK Dlg_Proc (HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	switch (uMsg)
	{
	chHANDLE_DLGMSG(hwnd, WM_INITDIALOG, Dlg_OnInitDialog);
	chHANDLE_DLGMSG(hwnd, WM_SIZE, Dlg_OnSize);

	}

	return(FALSE);
}

// Dialog
IDD_DIRWALK DIALOG DISCARDABLE 10, 18, 250, 250
STYLE WS_MINIMIZEBOX | WS_MAXIMIZEBOX | WS_POPUP|
              WS_VISIBLE| WS_CAPTION | WS_SYSMENU |WS_THICKFRAME
CAPTION "Directory Walk"
FONT 8, "System"
BEGIN
       LISTBOX     IDC_TREE,0,0,0,0,NOT LBS_NOTIFY |
	                      LBX_NOINTEGRAL_HEIGHT | NOT WS_BORDER |
			   WS_VSCROLL | WS_HSCROLL | WS_GROUP |
			   WS_TABSTOP
END

#define chHANDLE_DLGMSG(hWnd, message, fn)                                         \
	case (message):                                                                \
return (SetDlgMsgResult(hwnd, uMsg, HANDLE_##message((hwnd),  (wParam), (lParam), (fn))))