#include <wx/snglinst.h>
To do it, you should create an object of this class. As long as this object is alive, calls to wxSingleInstanceChecker::IsAnotherRunning from other processes will return true.
As the object should have the life span as big as possible, it makes sense to create it either as a global or in wxApp::OnInit. For example:
bool MyApp::OnInit() { const wxString name = wxString::Format("MyApp-%s", wxGetUserId().c_str()); m_checker = new wxSingleInstanceChecker(name); if ( m_checker-IsAnotherRunning() ) { wxLogError(_("Another program instance is already running, aborting.")); delete m_checker; // OnExit() won't be called if we return false m_checker = NULL; return false; } ... more initializations ... return true; } int MyApp::OnExit() { delete m_checker; return 0; }
Note using wxGetUserId() to construct the name: this allows different user to run the application concurrently which is usually the intended goal. If you don't use the user name in the wxSingleInstanceChecker name, only one user would be able to run the application at a time.
This class is implemented for Win32 and Unix platforms (supporting fcntl()
system call, but almost all of modern Unix systems do) only.
Public Member Functions | |
wxSingleInstanceChecker () | |
Default ctor, use Create() after it. | |
wxSingleInstanceChecker (const wxString &name, const wxString &path=wxEmptyString) | |
Like Create() but without error checking. | |
~wxSingleInstanceChecker () | |
Destructor frees the associated resources. | |
bool | Create (const wxString &name, const wxString &path=wxEmptyString) |
Initialize the object if it had been created using the default constructor. | |
bool | IsAnotherRunning () const |
Returns true if another copy of this program is already running, false otherwise. |
wxSingleInstanceChecker::wxSingleInstanceChecker | ( | ) |
Default ctor, use Create() after it.
wxSingleInstanceChecker::wxSingleInstanceChecker | ( | const wxString & | name, | |
const wxString & | path = wxEmptyString | |||
) |
Like Create() but without error checking.
wxSingleInstanceChecker::~wxSingleInstanceChecker | ( | ) |
Destructor frees the associated resources.
Note that it is not virtual, this class is not meant to be used polymorphically.
bool wxSingleInstanceChecker::Create | ( | const wxString & | name, | |
const wxString & | path = wxEmptyString | |||
) |
Initialize the object if it had been created using the default constructor.
Note that you can't call Create() more than once, so calling it if the non default ctor had been used is an error.
name | Must be given and be as unique as possible. It is used as the mutex name under Win32 and the lock file name under Unix. GetAppName() and wxGetUserId() are commonly used to construct this parameter. | |
path | The path is optional and is ignored under Win32 and used as the directory to create the lock file in under Unix (default is wxGetHomeDir()). |
bool wxSingleInstanceChecker::IsAnotherRunning | ( | ) | const |
Returns true if another copy of this program is already running, false otherwise.
![]() |
[ top ] |