[c++/mingw/winapi] zmiana tapety

   SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, "c:\\plik.bmp",
   SPIF_UPDATEINIFILE || SPIF_SENDWININICHANGE);

#define _WIN32_WINNT 0x0500
#define _WIN32_IE 0x600
#include <windows.h>

// next two are for ActiveDesktop and IE stuff
#include <winuser.h>
#include <WININET.H>
#include <shlobj.h>
#include "shlwapi.h"
#include <tchar.h>
#include <string>
#include <iostream>
using namespace std;


class CRegistry
{
private:
	static void DisplayErrorMessage(string cstrMethodName)
	{
		LPVOID lpMsgBuf;
		string cstrCaption;

		if (GetLastError() != 0)
		{
			char buf[255];
			sprintf(buf,"Utility Class Error in %s (%d)", cstrMethodName.c_str(), GetLastError());

			FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | 
				FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(), 
				MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf,
				0, NULL);

			MessageBox(NULL,(const char*)lpMsgBuf, cstrCaption.c_str(), MB_OK);
		}
	};

public:
	// Get a DWORD value from the registry
	static DWORD GetRegDWORD(string cstrKeyName, string cstrValueName, 
		DWORD dwDefault = 0, HKEY hBaseKey = HKEY_CURRENT_USER)
	{
		HKEY hKey;
        DWORD dwBufLen = sizeof(DWORD);
		DWORD dwReturn = dwDefault;
		BOOL bError = TRUE;

        if (RegOpenKeyEx(hBaseKey, cstrKeyName.c_str(), 0, KEY_QUERY_VALUE, &hKey) == ERROR_SUCCESS)
		{
			if (RegQueryValueEx(hKey, cstrValueName.c_str(), NULL, NULL, (LPBYTE) &dwReturn, &dwBufLen) == ERROR_SUCCESS) 
				bError = FALSE;

			RegCloseKey(hKey);
		}
	
		if (bError) DisplayErrorMessage("GetRegDWORD");

		return dwReturn;
	};

	// Set a DWORD value in the registry
	static void SetRegDWORD(string cstrKeyName, string cstrValueName, DWORD dwValue, 
		HKEY hBaseKey = HKEY_CURRENT_USER)
	{
		HKEY hKey;
		LONG lRet;
		BOOL bError = TRUE;

		lRet = RegOpenKeyEx(hBaseKey, cstrKeyName.c_str(), 0, KEY_SET_VALUE, &hKey);
        if (lRet != ERROR_SUCCESS)
			lRet = RegCreateKeyEx(hBaseKey, cstrKeyName.c_str(), 0, "", 0, KEY_READ | KEY_WRITE, NULL, &hKey, NULL); 
		
		if (lRet == ERROR_SUCCESS)
		{
			if (RegSetValueEx(hKey, cstrValueName.c_str(), NULL, REG_DWORD, (LPBYTE) &dwValue, sizeof(DWORD)) == ERROR_SUCCESS)
				bError = FALSE;

			RegCloseKey(hKey);
		}

		if (bError) DisplayErrorMessage("SetRegDWORD");
	};

	// Get a string value from the registry
	static string GetRegString(string cstrKeyName, string cstrValueName, 
		string cstrDefault = "", HKEY hBaseKey = HKEY_CURRENT_USER)
	{
		HKEY hKey;
        char szValue[MAX_PATH + 1];
		string cstrReturn = cstrDefault;
		DWORD dwBufLen = MAX_PATH + 1;
		BOOL bError = TRUE;

        if (RegOpenKeyEx(hBaseKey, cstrKeyName.c_str(), 0, KEY_QUERY_VALUE, &hKey) == ERROR_SUCCESS)
		{
			if (RegQueryValueEx(hKey, cstrValueName.c_str(), NULL, NULL, (LPBYTE) szValue, 
				&dwBufLen) == ERROR_SUCCESS)
			{
				cstrReturn = szValue;
				bError = FALSE;
			}

			RegCloseKey(hKey);
		}

		if (bError) DisplayErrorMessage("GetRegString");

		return cstrReturn;
	};

	// Set a string value in the registry
	static void SetRegString(string cstrKeyName, string cstrValueName, string cstrValue, HKEY hBaseKey = HKEY_CURRENT_USER)
	{
		HKEY hKey;
		LONG lRet;
		BOOL bError = TRUE;

		lRet = RegOpenKeyEx(hBaseKey, cstrKeyName.c_str(), 0, KEY_SET_VALUE, &hKey);
        if (lRet != ERROR_SUCCESS)
			lRet = RegCreateKeyEx(hBaseKey, cstrKeyName.c_str(), 0, "", 0, KEY_READ | KEY_WRITE, NULL, &hKey, NULL); 
		
		if (lRet == ERROR_SUCCESS)
		{
			if (RegSetValueEx(hKey, cstrValueName.c_str(), NULL, REG_SZ, 
					(const unsigned char*)cstrValue.c_str(), cstrValue.length()) != ERROR_SUCCESS)
				bError = FALSE;

			RegCloseKey(hKey);
		}

		if (bError) DisplayErrorMessage("SetRegString");
	};

	// Delete a value or key from the registry
	static BOOL RegDelete(string cstrKeyName, string cstrValueName = "", string cstrSubKeyName = "", 
		HKEY hBaseKey = HKEY_CURRENT_USER)
	{
		HKEY hKey;
		BOOL bRetVal = FALSE;
		BOOL bError = TRUE;

		if (RegOpenKeyEx(hBaseKey, cstrKeyName.c_str(), 0, KEY_WRITE, &hKey) == ERROR_SUCCESS)
		{
			if (cstrValueName.length())
			{
				// delete a value
				if (RegDeleteValue(hKey, cstrValueName.c_str()) == ERROR_SUCCESS)
				{
					bRetVal = TRUE;
					bError = FALSE;
				}
			}
			else
			{
				if (cstrSubKeyName.length())
				{
					// delete an entire key
					if (SHDeleteKey(hKey, cstrSubKeyName.c_str()) == ERROR_SUCCESS)
					{
						bRetVal = TRUE;
						bError = FALSE;
					}
				}
			}

			RegCloseKey(hKey);
		}

		if (bError) DisplayErrorMessage("RegDelete");

		return bRetVal;
	}
};

//decleare this variable in the .h file//
IActiveDesktop* pIActiveDesktop;
//////////////////////////////////////////

enum { tiled = 0, centered, stretch };

int main()
{
	int iPosition = stretch;

	string cstrTileWallpaper = "C:\\WINDOWS\\Web\\Wallpaper\\ascent.jpg"; 
	string cstrWallpaperStyle;
	TCHAR szBuf[MAX_PATH];

	pIActiveDesktop = NULL;

	CoInitialize(NULL);

	HRESULT hr = CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_INPROC_SERVER, 
		IID_IActiveDesktop, (void**) &pIActiveDesktop);

	if (FAILED(hr))
		pIActiveDesktop = NULL;

	// If Active Desktop is not available, use the SystemParametersInfo function.
	if (pIActiveDesktop == NULL)
	{
			if (iPosition == 0)
			{
				// Tiled
				cstrTileWallpaper = "1";
				cstrWallpaperStyle = "1";
			}
			else if (iPosition == 1)
			{
				// Center
				cstrTileWallpaper = "0";
				cstrWallpaperStyle = "1";
			}
			else
			{
				// Stretch
				cstrTileWallpaper = "0";
				cstrWallpaperStyle = "2";
			}

			// Set registry values for the wallpaper position.
			CRegistry::SetRegString("Control Panel\\Desktop", "TileWallpaper", cstrTileWallpaper);
			CRegistry::SetRegString("Control Panel\\Desktop", "WallpaperStyle", cstrWallpaperStyle);

			// Change the wallpaper.
			SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, (void*)szBuf, 
				SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE);	
		}
		else
		{
			WALLPAPEROPT wpOptions;
			COMPONENTSOPT compOptions;

			compOptions.dwSize = sizeof(COMPONENTSOPT);
			compOptions.fActiveDesktop = TRUE;
			compOptions.fEnableComponents = TRUE;

			pIActiveDesktop->SetDesktopItemOptions(&compOptions, 0);

			// Set the wallpaper position.
			wpOptions.dwSize = sizeof(WALLPAPEROPT);
			if (iPosition == 0)
				wpOptions.dwStyle = WPSTYLE_TILE;
			else if (iPosition == 1)
				wpOptions.dwStyle = WPSTYLE_CENTER;
			else
				wpOptions.dwStyle = WPSTYLE_STRETCH;

			pIActiveDesktop->SetWallpaperOptions(&wpOptions, 0);

			// Set the wallpaper image.
			int len = cstrTileWallpaper.length()+1;
			wchar_t* tbuf = new wchar_t[len];
			mbstowcs(tbuf,cstrTileWallpaper.c_str(),len);
			pIActiveDesktop->SetWallpaper(tbuf, 0);
			delete[] tbuf;

			// Apply all changes.
			pIActiveDesktop->ApplyChanges(AD_APPLY_ALL);
		}
	CoUninitialize();
	return 0;
}