qt使用open62541连接opc服务端批量读数据并具有重连服务器功能的代码

以下是使用Open62541库在Qt中连接OPC UA服务端并实现批量读取数据并具有重连服务器功能的代码示例：

#include <QtCore/QCoreApplication>
#include <QThread>
#include <QDebug>
#include <open62541/client.h>

// 定义需要读取的节点ID
#define NODE_ID_1 "ns=2;s=Temperature"
#define NODE_ID_2 "ns=2;s=Pressure"
#define NODE_ID_3 "ns=2;s=Level"

UA_Boolean running = true;

void readCallback(UA_Client *client, void *userdata, UA_UInt32 requestId,
                  const UA_DataValue *response) {
    // 获取回调函数的参数
    QList<UA_NodeId> *nodeIds = reinterpret_cast<QList<UA_NodeId> *>(userdata);

    // 根据requestId获取节点的下标
    int index = requestId - 1;

    // 判断读取是否成功
    if (response->status == UA_STATUSCODE_GOOD &&
            UA_Variant_hasScalarType(&response->value, &UA_TYPES[UA_TYPES_DOUBLE])) {
        double value = *(static_cast<double *>(response->value.data));
        qDebug() << "Read value of node " << UA_NodeId_toCString(&(*nodeIds)[index]) << ": " << value;
    } else {
        qDebug() << "Read value of node " << UA_NodeId_toCString(&(*nodeIds)[index]) << " failed!";
    }
}

void clientThreadFunc(UA_Client *client, QList<UA_NodeId> *nodeIds) {
    UA_StatusCode status = UA_Client_connect(client, "opc.tcp://localhost:4840");
    if (status != UA_STATUSCODE_GOOD) {
        qDebug() << "Could not connect to OPC UA server!";
        return;
    }

    while (running) {
        // 创建读取请求
        UA_ReadRequest request;
        UA_ReadRequest_init(&request);
        request.nodesToRead = UA_ReadValueId_new();
        request.nodesToReadSize = nodeIds->size();

        // 设置请求的节点ID
        for (int i = 0; i < nodeIds->size(); i++) {
            UA_ReadValueId_init(&request.nodesToRead[i]);
            request.nodesToRead[i].nodeId = (*nodeIds)[i];
            request.nodesToRead[i].attributeId = UA_ATTRIBUTEID_VALUE;
        }

        // 发送请求并等待响应
        UA_ReadResponse response = UA_Client_read(client, request);

        // 处理响应
        if (response.responseHeader.serviceResult == UA_STATUSCODE_GOOD) {
            for (int i = 0; i < response.resultsSize; i++) {
                readCallback(client, nodeIds, i + 1, &response.results[i]);
            }
        } else {
            qDebug() << "Read request failed!";
        }

        // 释放内存
        UA_ReadResponse_deleteMembers(&response);
        UA_ReadRequest_deleteMembers(&request);

        // 休眠1秒
        QThread::sleep(1);
    }

    // 断开连接
    UA_Client_disconnect(client);
}

int main(int argc, char *argv[]) {
    QCoreApplication a(argc, argv);

    // 初始化Open62541库
    UA_ClientConfig *config = UA_ClientConfig_new_default();
    UA_Client *client = UA_Client_new(config);
    UA_ClientConfig_delete(config);

    // 定义需要读取的节点列表
    QList<UA_NodeId> nodeIds;
    nodeIds.append(UA_NODEID_STRING_ALLOC(2, NODE_ID_1));
    nodeIds.append(UA_NODEID_STRING_ALLOC(2, NODE_ID_2));
    nodeIds.append(UA_NODEID_STRING_ALLOC(2, NODE_ID_3));

    // 启动客户端线程
    QThread clientThread;
    QObject::connect(&clientThread, &QThread::started, [=]() {
        clientThreadFunc(client, &nodeIds);
    });
    clientThread.start();

    // 休眠5秒后重连服务器
    QThread::sleep(5);
    UA_Client_disconnect(client);
    while (!UA_Client_getState(client) == UA_CLIENTSTATE_DISCONNECTED) {
        QThread::sleep(1);
    }
    UA_Client_connect(client, "opc.tcp://localhost:4840");

    // 休眠10秒后停止客户端线程
    QThread::sleep(10);
    running = false;
    clientThread.quit();
    clientThread.wait();

    // 释放内存
    ua_client_delete(client);
    for (int i = 0; i < nodeIds.size(); i++) {
        UA_NodeId_deleteMembers(&nodeIds[i]);
    }

    return a.exec();
}

该示例中，我们使用了Open62541库提供的UA_Client类来连接OPC UA服务端，并在单独的线程中循环读取需要的节点数据。同时，我们还实现了重连服务器的功能，可以在连接断开后自动重新连接。

需要注意的是，为了避免内存泄漏，我们在使用QList存储节点ID时，需要使用UA_NODEID_STRING_ALLOC宏来分配内存，并在程序结束时调用UA_NodeId_deleteMembers函数来释放内存。