禁止重复启动

.gitignore

@@ -68,4 +68,4 @@ Thumbs.db
 
 # Binaries
 # --------
-*.exe
+bin/*.exe

FmclientUi.pro

@@ -24,6 +24,7 @@ SOURCES += main.cpp\
 
 HEADERS  += widget.h \
     fmcrypt.h \
-    qfmclient.h
+    qfmclient.h \
+    app_single.h
 
 FORMS    += widget.ui

app_single.h

+#ifndef APP_SINGLE
+#define APP_SINGLE
+
+#if defined WIN32    //for win
+#include <windows.h>
+bool checkOnly()
+{
+    //  创建互斥量
+    HANDLE m_hMutex  =  CreateMutex(NULL, FALSE,  L"FmclientUi" );
+    //  检查错误代码
+    if  (GetLastError()  ==  ERROR_ALREADY_EXISTS)  {
+        //  如果已有互斥量存在则释放句柄并复位互斥量
+        CloseHandle(m_hMutex);
+        m_hMutex  =  NULL;
+        //  程序退出
+        return  false;
+    }
+    else
+        return true;
+}
+#endif
+#if defined  Q_OS_LINUX   //for linux
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+bool checkOnly()
+{
+    const char filename[]  = "/tmp/lockfile";
+    int fd = open (filename, O_WRONLY | O_CREAT , 0644);
+    int flock = lockf(fd, F_TLOCK, 0 );
+    if (fd == -1) {
+        perror("open lockfile/n");
+        return false;
+    }
+    //给文件加锁
+    if (flock == -1) {
+        perror("lock file error/n");
+        return false;
+    }
+    //程序退出后，文件自动解锁
+    return true;
+}
+#endif
+
+#endif // APP_SINGLE
+

main.cpp

 #include "widget.h"
 #include <QApplication>
 #include "qfmclient.h"
-
+#include "app_single.h"
 
 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
+    if(!checkOnly())
+    {
+        OutputDebugString(L"FmclientUi running.");
+        return 0;
+    }
     Widget w;
     QFmClient client;
     QObject::connect(&client,&QFmClient::HideUi, &w, &Widget::hide,Qt::QueuedConnection);