QDBusPendingCallWatcher Class

The QDBusPendingCallWatcher class provides a convenient way for waiting for asynchronous replies 更多...

头文件:	#include <QDBusPendingCallWatcher>
qmake:	QT += dbus
开始支持版本:	Qt 4.5
基类:	QObject and QDBusPendingCall

所有的成员列表, 包括继承的成员

公有函数

	QDBusPendingCallWatcher(const QDBusPendingCall &call, QObject *parent = Q_NULLPTR)
	~QDBusPendingCallWatcher()
bool	isFinished() const
void	waitForFinished()

32 个公有函数继承自 QObject
3 个公有函数继承自 QDBusPendingCall

信号

void	finished(QDBusPendingCallWatcher *self = Q_NULLPTR)

2 个信号继承自 QObject

其他继承的成员

1 个属性继承自 QObject
1 个公有槽函数继承自 QObject
1 个公有变量继承自 QObject
10 个静态公有成员继承自 QObject
2 个静态公有成员继承自 QDBusPendingCall
9 个受保护的函数继承自 QObject
2 个受保护的变量继承自 QObject

详细描述

The QDBusPendingCallWatcher class provides a convenient way for waiting for asynchronous replies

The QDBusPendingCallWatcher provides the finished() signal that will be emitted when a reply arrives.

It is usually used like the following example:


      QDBusPendingCall async = iface->asyncCall("RemoteMethod", value1, value2);
      QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(async, this);

      QObject::connect(watcher, SIGNAL(finished(QDBusPendingCallWatcher*)),
                       this, SLOT(callFinishedSlot(QDBusPendingCallWatcher*)));

Note that it is not necessary to keep the original QDBusPendingCall object around since QDBusPendingCallWatcher inherits from that class too.

The slot connected to by the above code could be something similar to the following:


  void MyClass::callFinishedSlot(QDBusPendingCallWatcher *call)
  {
      QDBusPendingReply<QString, QByteArray> reply = *call;
      if (reply.isError()) {
          showError();
      } else {
          QString text = reply.argumentAt<0>();
          QByteArray data = reply.argumentAt<1>();
          showReply(text, data);
      }
      call->deleteLater();
  }

Note the use of QDBusPendingReply to validate the argument types in the reply. If the reply did not contain exactly two arguments (one string and one QByteArray), QDBusPendingReply::isError() will return true.

参见 QDBusPendingReply and QDBusAbstractInterface::asyncCall().

成员函数

QDBusPendingCallWatcher::QDBusPendingCallWatcher(const QDBusPendingCall &call, QObject **parent* = Q_NULLPTR)

Creates a QDBusPendingCallWatcher object to watch for replies on the asynchronous pending call call and sets this object's parent to parent.

QDBusPendingCallWatcher::~QDBusPendingCallWatcher()

Destroys this object. If this QDBusPendingCallWatcher object was the last reference to the unfinished pending call, the call will be canceled.

`[signal]` void QDBusPendingCallWatcher::finished(QDBusPendingCallWatcher **self* = Q_NULLPTR)

This signal is emitted when the pending call has finished and its reply is available. The self parameter is a pointer to the object itself, passed for convenience so that the slot can access the properties and determine the contents of the reply.

bool QDBusPendingCallWatcher::isFinished() const

Returns true if the pending call has finished processing and the reply has been received.

Note that this function only changes state if you call waitForFinished() or if an external D-Bus event happens, which in general only happens if you return to the event loop execution.

参见 QDBusPendingReply::isFinished().

void QDBusPendingCallWatcher::waitForFinished()

Suspends the execution of the calling thread until the reply is received and processed. After this function returns, isFinished() should return true, indicating the reply's contents are ready to be processed.

参见 QDBusPendingReply::waitForFinished().

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