QOpcUaProvider Class

QOpcUaProvider creates an instance of QOpcUaClient . 更多...

头：	#include <QOpcUaProvider>
qmake:	QT += opcua
继承：	QObject

所有成员列表，包括继承成员

公共函数

	QOpcUaProvider (QObject * parent = nullptr)
QOpcUaClient *	createClient (const QString & backend , const QVariantMap & backendProperties = QVariantMap())

静态公共成员

QStringList

availableBackends ()

详细描述

QOpcUaProvider allows the user to create an instance of QOpcUaClient by loading a QOpcUaPlugin using the Qt plugin system.

For the available plugins and their capabilities please refer to the introduction .

范例

This code creates a client using the first available backend:

QOpcUaProvider provider;
QStringList available = provider.availableBackends();
if (!available.isEmpty()) {
    QOpcUaClient *client = provider.createClient(available[0]);
    if (client)
        qDebug() << "Client successfully created";
}

成员函数文档编制

QOpcUaProvider:: QOpcUaProvider ( QObject * parent = nullptr)

Creates a new OPC UA provider with a given parent .

`[static]` QStringList QOpcUaProvider:: availableBackends ()

返回 QStringList of available plugins.

`[invokable]` QOpcUaClient QOpcUaProvider:: createClient (const QString & backend* , const QVariantMap & backendProperties = QVariantMap())

返回指针指向 QOpcUaClient object by loading the selected backend as a plugin and creating a client object. If the plugin loading fails, nullptr 被返回取而代之。

The user is responsible for deleting the returned QOpcUaClient object when it is no longer needed.

The optional argument backendProperties can be used to pass custom backend specific settings as key value pairs. Those settings are specific to the backend being instantiated.

Available settings are

Setting string	Backend	描述
disableEncryptedPasswordCheck	Unified Automation	By default, the backend refuses to connect to endpoints without encryption to avoid sending passwords in clear text. This parameter allows to disable this feature.
enableVerboseDebugOutput	Unified Automation	Tells the backend to print additional output to the terminal. The backend specific logging level is set to `OPCUA_TRACE_OUTPUT_LEVEL_ALL` .
minimumClientIterateIntervalMs	open62541	This parameter is no longer evaluated by the backend and has been replaced by `clientIterateIntervalMs` .
clientIterateIntervalMs	open62541	Defines the client iterate interval for the backend. If the client is causing too much CPU load, setting this value higher than the default will reduce the CPU load at the price of an increased response time to service requests and value updates from subscriptions. The default value is 50ms.
asyncRequestTimeoutMs	open62541	Defines the timeout for asynchronous requests to an OPC UA server. If the server doesn't reply to a service request before the timeout occurs, the service call fails and the finished signal will contain a `bad` status code. The default value is 15000ms.

注意： 此函数可以被援引，通过元对象系统和从 QML。见 Q_INVOKABLE .

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