QDBusServiceWatcher 类允许用户看守总线服务改变。 更多...
| 头： | #include <QDBusServiceWatcher> |
| CMake: |
find_package(Qt6 COMPONENTS Dbus REQUIRED)
target_link_libraries(mytarget PRIVATE Qt6::Dbus) |
| qmake: | QT += dbus |
| 继承： | QObject |
| flags | WatchMode |
| enum | WatchModeFlag { WatchForRegistration, WatchForUnregistration, WatchForOwnerChange } |
| QDBusServiceWatcher (const QString & service , const QDBusConnection & connection , QDBusServiceWatcher::WatchMode watchMode = WatchForOwnerChange, QObject * parent = nullptr) | |
| QDBusServiceWatcher (QObject * parent = nullptr) | |
| virtual | ~QDBusServiceWatcher () |
| void | addWatchedService (const QString & newService ) |
| QDBusConnection | connection () const |
| bool | removeWatchedService (const QString & service ) |
| void | setConnection (const QDBusConnection & connection ) |
| void | setWatchMode (QDBusServiceWatcher::WatchMode mode ) |
| void | setWatchedServices (const QStringList & services ) |
| QDBusServiceWatcher::WatchMode | watchMode () const |
| QStringList | watchedServices () const |
| void | serviceOwnerChanged (const QString & serviceName , const QString & oldOwner , const QString & newOwner ) |
| void | serviceRegistered (const QString & serviceName ) |
| void | serviceUnregistered (const QString & serviceName ) |
A QDBusServiceWatcher object can be used to notify the application about an ownership change of a service name on the bus. It has three watch modes:
Besides being created or deleted, services may change owners without a unregister/register operation happening. So the serviceRegistered () 和 serviceUnregistered () signals may not be emitted if that happens.
This class is more efficient than using the QDBusConnectionInterface::serviceOwnerChanged() signal because it allows one to receive only the signals for which the class is interested in.
Ending a service name with the character '*' will match all service names within the specified namespace.
For example "com.example.backend1*" will match
Substrings in the same domain will not be matched, i.e "com.example.backend12".
另请参阅 QDBusConnection .
QDBusServiceWatcher supports three different watch modes, which are configured by this flag:
| 常量 | 值 | 描述 |
|---|---|---|
QDBusServiceWatcher::WatchForRegistration
|
0x01
|
watch for service registration only, ignoring any signals related to other service ownership change. |
QDBusServiceWatcher::WatchForUnregistration
|
0x02
|
watch for service unregistration only, ignoring any signals related to other service ownership change. |
QDBusServiceWatcher::WatchForOwnerChange
|
0x03
|
watch for any kind of service ownership change. |
The WatchMode type is a typedef for QFlags <WatchModeFlag>. It stores an OR combination of WatchModeFlag values.
[bindable]
watchMode
:
WatchMode
注意： 此特性支持 QProperty 绑定。
This property holds the current watch mode for this QDBusServiceWatcher 对象。
The default value for this property is QDBusServiceWatcher::WatchForOwnershipChange.
[bindable]
watchedServices
:
QStringList
注意： 此特性支持 QProperty 绑定。
This property holds the list of services watched.
注意： Modifying this list with setServicesWatched() is an expensive operation. If you can, prefer to change it by way of addWatchedService () 和 removeWatchedService ().
Creates a QDBusServiceWatcher object and attaches it to the connection connection. Also, this function immediately starts watching for watchMode changes to service service .
parent 参数会被传递给 QObject to set the parent of this object.
Creates a QDBusServiceWatcher object. Note that until you set a connection with setConnection (), this object will not emit any signals.
parent 参数会被传递给 QObject to set the parent of this object.
[signal]
void
QDBusServiceWatcher::
serviceOwnerChanged
(const
QString
&
serviceName
, const
QString
&
oldOwner
, const
QString
&
newOwner
)
This signal is emitted whenever this object detects that there was a service ownership change relating to the serviceName service. The oldOwner parameter contains the old owner name and newOwner is the new owner. Both oldOwner and newOwner are unique connection names.
Note that this signal is also emitted whenever the serviceName service was registered or unregistered. If it was registered, oldOwner will contain an empty string, whereas if it was unregistered, newOwner will contain an empty string.
If you need only to find out if the service is registered or unregistered only, without being notified that the ownership changed, consider using the specific modes for those operations. This class is more efficient if you use the more specific modes.
另请参阅 serviceRegistered () 和 serviceUnregistered ().
[signal]
void
QDBusServiceWatcher::
serviceRegistered
(const
QString
&
serviceName
)
This signal is emitted whenever this object detects that the service serviceName became available on the bus.
另请参阅 serviceUnregistered () 和 serviceOwnerChanged ().
[signal]
void
QDBusServiceWatcher::
serviceUnregistered
(const
QString
&
serviceName
)
This signal is emitted whenever this object detects that the service serviceName was unregistered from the bus and is no longer available.
另请参阅 serviceRegistered () 和 serviceOwnerChanged ().
[虚拟]
QDBusServiceWatcher::
~QDBusServiceWatcher
()
销毁 QDBusServiceWatcher object and releases any resources associated with it.
添加 newService to the list of services to be watched by this object. This function is more efficient than setWatchedServices () and should be used whenever possible to add services.
Removes any existing binding of watchedServices .
返回 QDBusConnection that this object is attached to.
另请参阅 setConnection ().
移除 service from the list of services being watched by this object. Note that D-Bus notifications are asynchronous, so there may still be signals pending delivery about service . Those signals will still be emitted whenever the D-Bus messages are processed.
Removes any existing binding of watchedServices .
此函数返回
true
if any services were removed.
Sets the D-Bus connection that this object is attached to be connection . All services watched will be transferred to this connection.
注意， QDBusConnection objects are reference counted: QDBusServiceWatcher will keep a reference for this connection while it exists. The connection is not closed until the reference count drops to zero, so this will ensure that any notifications are received while this QDBusServiceWatcher object exists.
另请参阅 connection ().
Sets the list of D-Bus services being watched to be services .
Note that setting the entire list means removing all previous rules for watching services and adding new ones. This is an expensive operation and should be avoided, if possible. Instead, use addWatchedService () 和 removeWatchedService () if you can to manipulate entries in the list.
Removes any existing binding of watchedServices .
注意： setter 函数对于特性 watchedServices .
另请参阅 watchedServices ().
Returns the list of D-Bus services that are being watched.
注意： Getter function for property watchedServices.
另请参阅 setWatchedServices ().