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Windows Qt打开外部程序

news 2025/11/7 12:25:16

前言

使用QProcess可以在Qt程序中打开外部第三方程序，但是每次执行都会重复运行多次，所以在打开之前要先判断该进程是否已经启动过，如果已经打开过，则使用Window API将该程序窗口置顶展示。
在这里插入图片描述

代码

注意，使用了Windows 接口，只能在win平台使用。


#ifdef Q_OS_WIN
#include <windows.h>
#include <tlhelp32.h>
#endif
bool openExternalProgram(const QString &filePath)
{auto path = filePath.trimmed();qDebug() << __FUNCTION__ << "path" << path;if(!QFile::exists(path))return false;#ifdef Q_OS_WIN// 1) Windows: 如果进程已运行，则置顶其窗口并返回QString exeName = QFileInfo(path).fileName();// 查找目标进程PID（按可执行文件名匹配）DWORD foundPid = 0;HANDLE snap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);if (snap != INVALID_HANDLE_VALUE) {PROCESSENTRY32W pe;pe.dwSize = sizeof(pe);if (Process32FirstW(snap, &pe)) {do {QString name = QString::fromWCharArray(pe.szExeFile);if (name.compare(exeName, Qt::CaseInsensitive) == 0) {foundPid = pe.th32ProcessID;break;}} while (Process32NextW(snap, &pe));}CloseHandle(snap);}if (foundPid != 0) {// 根据PID枚举窗口并置顶第一个可见的顶层窗口struct WinEnumData { DWORD pid; HWND hwnd; } data{foundPid, nullptr};auto enumProc = [](HWND hwnd, LPARAM lParam) -> BOOL {WinEnumData* d = reinterpret_cast<WinEnumData*>(lParam);DWORD wpid = 0;GetWindowThreadProcessId(hwnd, &wpid);// 顶层窗口且可见if (wpid == d->pid && IsWindowVisible(hwnd) && GetWindow(hwnd, GW_OWNER) == nullptr) {d->hwnd = hwnd;return FALSE; // 找到后停止枚举}return TRUE;};EnumWindows(enumProc, reinterpret_cast<LPARAM>(&data));if (data.hwnd) {// 若窗口最小化，先恢复if (IsIconic(data.hwnd)) {ShowWindow(data.hwnd, SW_RESTORE);}// 置顶并激活SetForegroundWindow(data.hwnd);SetActiveWindow(data.hwnd);SetWindowPos(data.hwnd, HWND_TOP, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);qDebug() << "Process already running. Brought window to front.";return true;}}
#endif// 2) 未运行或未找到窗口，则启动新进程QStringList arguments; // 如有参数再添加QString workingDir = QFileInfo(path).absolutePath(); // 常见做法：以exe所在目录为工作目录bool ok = QProcess::startDetached(path, arguments, workingDir);if (!ok) {qDebug() << "startDetached failed. Check:"<< "\n  - File exists:" << QFileInfo(path).exists()<< "\n  - Executable:" << QFileInfo(path).isExecutable()<< "\n  - Working dir accessible:" << QDir(workingDir).exists()<< "\n  - Try quoting the path or using the overload with arguments.";} else {qDebug() << "Started successfully.";}return ok;
}