获取windows桌面所有可见窗口信息

窗口信息主要有：窗口句柄、标题、类名、区域，还有一个ZOrder，它表示窗口显示在桌面的上下层级，窗口是否被遮盖。

#include <qt_windows.h>
#include <QDebug>

int GetWindowZOrder(HWND hwnd);

struct WindowInfo {
	HWND hWnd;
	QRect rect;
	QString title;
	QString className;
	int zOrder()
	{
		return GetWindowZOrder(hWnd);
	}
	QString debugString()
	{
		return QString().sprintf("hWnd:0x%x, ", hWnd) +
			QString("order:%1, title:%2, class:%3, rect:%4,%5,%6,%7").arg(zOrder()).arg(title).arg(className).
				arg(rect.left()).arg(rect.top()).arg(rect.width()).arg(rect.height());
	}
};

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam) {
	std::vector<HWND>* window_list = reinterpret_cast<std::vector<HWND>*>(lParam);
	if (::IsWindow(hwnd) && ::IsWindowVisible(hwnd)) {
		window_list->push_back(hwnd);
	}
	return TRUE;
}

QVector<WindowInfo> getAllValidWindows()
{
	QVector<WindowInfo> result;
	std::vector<HWND> window_list;
	EnumWindows(EnumWindowsProc, reinterpret_cast<LPARAM>(&window_list));
	const int BUFFER_LEN = 1024;
	for (auto it = window_list.rbegin(); it != window_list.rend(); ++it) {
		TCHAR buf[BUFFER_LEN] = { 0 };
		::GetWindowText(*it, buf, BUFFER_LEN - 1);
		TCHAR buf2[BUFFER_LEN] = { 0 };
		::GetClassName(*it, buf2, BUFFER_LEN - 1);
		RECT rect = { 0 };
		::GetWindowRect(*it, &rect);
		QRect qrect(rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top);
		if (qrect.isValid()) {
			WindowInfo info;
			info.className = QString::fromStdWString(buf2);
			info.hWnd = *it;
			info.rect = qrect;
			info.title = QString::fromStdWString(buf);
			result.push_back(info);
		}
	}
	return result;
}

int GetWindowZOrder(HWND hwnd)
{
	int zorder = 0;
	HWND hwndPrev = NULL;

	for (HWND hwndNext = GetTopWindow(NULL); hwndNext != NULL; hwndNext = GetNextWindow(hwndNext, GW_HWNDNEXT))
	{
		if (hwndNext == hwnd)
			return zorder;

		if (IsWindowVisible(hwndNext))
		{
			hwndPrev = hwndNext;
			zorder++;
		}
	}

	if (hwndPrev)
		return zorder;

	return -1;
}