QRemoteObjectReplica 类

与远程对象网络 Qt API 交互 (但未实现) 的类。更多...

头：	#include <QRemoteObjectReplica>
qmake:	QT += remoteobjects
继承：	QObject
继承者：	QRemoteObjectDynamicReplica and QRemoteObjectRegistry

所有成员列表，包括继承成员

公共类型

enum	State { Uninitialized, Default, Valid, Suspect, SignatureMismatch }

特性

node : QRemoteObjectNode*
state : const State

公共函数

bool	isInitialized () const
bool	isReplicaValid () const
QRemoteObjectNode *	node () const
virtual void	setNode (QRemoteObjectNode * node )
QRemoteObjectReplica::State	state () const
bool	waitForSource (int timeout = 30000)

信号

void	initialized ()
void	notified ()
void	stateChanged (QRemoteObjectReplica::State state , QRemoteObjectReplica::State oldState )

详细描述

A Remote Object Replica is a QObject proxy for another QObject (called the 源 object). Once initialized, a replica can be considered a "latent copy" of the 源 object. That is, every change to a Q_PROPERTY 在源 , or signal emitted by the 源 will be updated/emitted by all 复本 objects. Latency is introduced by process scheduling by any OSes involved and network communication latency. As long as the replica has been initialized and the communication is not disrupted, receipt and order of changes is guaranteed.

The isInitialized and state properties (and corresponding initialized ()/ stateChanged () signals) allow the state of a 复本 to be determined.

While Qt Remote Objects (QtRO) handles the initialization and synchronization of 复本 objects, there are numerous steps happening behind the scenes which can fail and that aren't encountered in single process Qt applications. See 故障排除 for advice on how to handle such issues when using a remote objects network.

成员类型文档编制

enum QRemoteObjectReplica:: State

This enum type specifies the various state codes associated with QRemoteObjectReplica states:

常量	值	描述
`QRemoteObjectReplica::Uninitialized`	`0`	initial value of DynamicReplica, where nothing is known about the replica before connection to source.
`QRemoteObjectReplica::Default`	`1`	initial value of static replica, where any defaults set in the .rep file are available so it can be used if necessary.
`QRemoteObjectReplica::Valid`	`2`	indicates the replica is connected, has good property values and can be interacted with.
`QRemoteObjectReplica::Suspect`	`3`	error state that occurs if the connection to the source is lost after it is initialized.
`QRemoteObjectReplica::SignatureMismatch`	`4`	error state that occurs if a connection to the source is made, but the source and replica are not derived from the same .rep (only possible for static Replicas).

特性文档编制

node : QRemoteObjectNode *

This property holds a pointer to the node this object was acquired from.

访问函数：

QRemoteObjectNode *	node () const
virtual void	setNode (QRemoteObjectNode * node )

state : const State

Returns the replica state.

This property holds the replica QRemoteObjectReplica::State .

访问函数：

QRemoteObjectReplica::State

state () const

通知程序信号：

void	stateChanged (QRemoteObjectReplica::State state , QRemoteObjectReplica::State oldState )

成员函数文档编制

`[signal]` void QRemoteObjectReplica:: initialized ()

This signal is emitted once the replica is initialized. An intialized replica has all property values set, but has not yet emitted any property change notifications.

另请参阅 isInitialized () 和 stateChanged ().

`[signal]` void QRemoteObjectReplica:: notified ()

This signal is emitted once the replica is initialized and all property change notifications have been emitted.

It is sometimes useful to respond to property changes as events. For example, you might want to display a user notification when a certain property change occurs. However, this user notification would then also be triggered when a replica first became QRemoteObjectReplica::Valid , as all property change signals are emitted at that time. This isn't always desirable, and notified allows the developer to distinguish between these two cases.

`[signal]` void QRemoteObjectReplica:: stateChanged ( QRemoteObjectReplica::State state , QRemoteObjectReplica::State oldState )

This signal is emitted whenever a replica's state toggles between QRemoteObjectReplica::State .

The change in state is represented with state and oldState .

注意： 通知程序信号对于特性 state .

另请参阅 state () 和 initialized ().

bool QRemoteObjectReplica:: isInitialized () const

返回 true 若此复本已初始化采用数据来自源对象。返回 false 否则。

另请参阅 state ().

bool QRemoteObjectReplica:: isReplicaValid () const

返回 true if this replica has been initialized and has a valid connection with the node hosting the 源。返回 false 否则。

另请参阅 isInitialized ().

QRemoteObjectReplica::State QRemoteObjectReplica:: state () const