C语言服务器和Qt客户端通信：实时获取设备状态并发送建议

"#include <stdio.h>\n#include <stdlib.h>\n#include <string.h>\n#include <unistd.h>\n#include <sys/socket.h>\n#include <arpa/inet.h>\n#include <sqlite3.h>\n\n#define MAX_BUFFER_SIZE 1024\n\ntypedef struct {\n int uid;\n char device_name[10];\n char device_state[10];\n char value[10];\n char mode[10];\n} Status;\n\ntypedef struct {\n int sockfd;\n struct sockaddr_in client_addr;\n socklen_t client_addr_len;\n sqlite3 *db;\n} ServerContext;\n\nvoid handleClientRequest(ServerContext *context) {\n char buffer[MAX_BUFFER_SIZE];\n int userid;\n\n // 接收客户端发送的userid\n ssize_t recvSize = recv(context->sockfd, &userid, sizeof(int), 0);\n if (recvSize == -1) {\n perror("userid接受失败\nrecv");\n return;\n }\n\n // 查询数据库获取设备状态信息\n char sql[100];\n snprintf(sql, sizeof(sql), "SELECT * FROM Status WHERE uid = %d", userid);\n sqlite3_stmt *stmt;\n int rc = sqlite3_prepare_v2(context->db, sql, -1, &stmt, NULL);\n if (rc != SQLITE_OK) {\n fprintf(stderr, "无法执行的语句: %s\n", sqlite3_errmsg(context->db));\n return;\n }\n\n Status status;\n while (sqlite3_step(stmt) == SQLITE_ROW) {\n status.uid = sqlite3_column_int(stmt, 0);\n strncpy(status.device_name, sqlite3_column_text(stmt, 1), sizeof(status.device_name));\n strncpy(status.device_state, sqlite3_column_text(stmt, 2), sizeof(status.device_state));\n strncpy(status.value, sqlite3_column_text(stmt, 3), sizeof(status.value));\n strncpy(status.mode, sqlite3_column_text(stmt, 4), sizeof(status.mode));\n }\n sqlite3_finalize(stmt);\n\n // 分析设备状态并生成建议\n char suggestion[MAX_BUFFER_SIZE];\n if (strcmp(status.device_name, "空调") == 0) {\n int temperature = atoi(status.value);\n if (temperature < 24) {\n snprintf(suggestion, sizeof(suggestion), "空调温度过低，建议提高温度至26℃");\n } else {\n snprintf(suggestion, sizeof(suggestion), "空调温度正常");\n }\n } else if (strcmp(status.device_name, "加湿器") == 0) {\n int humidity = atoi(status.value);\n if (humidity < 40 || humidity > 70) {\n snprintf(suggestion, sizeof(suggestion), "加湿器湿度过高或过低，建议调整加湿器湿度");\n } else {\n snprintf(suggestion, sizeof(suggestion), "加湿器湿度正常");\n }\n } else {\n snprintf(suggestion, sizeof(suggestion), "设备状态未知");\n }\n\n // 向客户端发送建议\n ssize_t sendSize = send(context->sockfd, suggestion, strlen(suggestion), 0);\n if (sendSize == -1) {\n perror("发送失败\nsend");\n return;\n }\n}\n\nvoid handleClientConnection(ServerContext *context) {\n int clientSockfd = accept(context->sockfd, (struct sockaddr *)&context->client_addr, &context->client_addr_len);\n if (clientSockfd == -1) {\n perror("套接字接收失败\naccept");\n return;\n }\n\n ServerContext clientContext;\n clientContext.sockfd = clientSockfd;\n clientContext.client_addr_len = sizeof(clientContext.client_addr);\n clientContext.db = context->db;\n handleClientRequest(&clientContext);\n\n close(clientSockfd);\n}\n\nint main() {\n printf("正在连接中...");\n int sockfd = socket(AF_INET, SOCK_STREAM, 0);\n if (sockfd == -1) {\n perror("连接失败\nsocket");\n return 1;\n }\n\n struct sockaddr_in server_addr;\n server_addr.sin_family = AF_INET;\n server_addr.sin_addr.s_addr = INADDR_ANY;\n server_addr.sin_port = htons(12345);\n\n if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {\n perror("连接失败\nbind");\n close(sockfd);\n return 1;\n }\n\n if (listen(sockfd, 5) == -1) {\n perror("连接失败\nlisten");\n close(sockfd);\n return 1;\n }\n\n printf("客户端已连接");\n sqlite3 *db;\n int rc = sqlite3_open("/mnt/g/Qt/Client/Smarthome_Client/database/database.db", &db);\n if (rc != SQLITE_OK) {\n fprintf(stderr, "数据库打开失败: %s\n", sqlite3_errmsg(db));\n return 1;\n }\n\n ServerContext context;\n context.sockfd = sockfd;\n context.client_addr_len = sizeof(context.client_addr);\n context.db = db;\n\n\n while (1) {\n sleep(1);\n handleClientConnection(&context);\n }\n\n sqlite3_close(db);\n close(sockfd);\n printf("服务器已关闭");\n\n return 0;\n}\n\n\n#include "procession.h"\n#include "ui_procession.h"\n#include \n#include \n\nProcession::Procession(int userid,QWidget *parent) :\n QWidget(parent),\n ui(new Ui::Procession),\n userid(userid)\n{\n ui->setupUi(this);\n processionWidget();\n m_socket = new QTcpSocket(this);\n connect(ui->connectBtn, &QPushButton::clicked, this, &Procession::on_connectBtn_clicked);\n connect(m_socket, &QTcpSocket::readyRead, this, &Procession::readyRead);\n connect(m_socket, &QTcpSocket::connected, this, &Procession::connected);\n connect(m_socket, &QTcpSocket::disconnected,this,&Procession::disconnected);\n connect(m_socket, QOverloadQAbstractSocket::SocketError::of(&QTcpSocket::error), this, &Procession::displayError);\n}\n\nProcession::~Procession()\n{\n delete ui;\n}\n\nvoid Procession::processionWidget()\n{\n setWindowTitle("服务器通信");\n setAutoFillBackground(true);\n QPalette palette=this->palette();\n QPixmap pixmap(":/user/image/image/net.jpg");\n palette.setBrush(QPalette::Window, QBrush(pixmap));\n setPalette(palette);\n setFixedSize(600,400);\n}\nvoid Procession::on_connectBtn_clicked()\n{\n if (m_socket->state() == QAbstractSocket::ConnectedState) {\n ui->message->append("已经连接上服务器");\n return;\n }\n\n QString ip = ui->IP->text();\n QString port = ui->port->text();\n\n if (ip.isEmpty() || port.isEmpty()) {\n ui->message->clear();\n ui->message->append("请输入有效的IP地址和端口号");\n return;\n }\n\n ui->message->clear();\n ui->message->append("正在连接中...");\n m_socket->connectToHost(ip, static_cast(ui->port->text().toInt()));\n}\n\nvoid Procession::connected()\n{\n ui->message->append("连接成功");\n // 发送userid给服务器\n QByteArray block;\n QDataStream out(&block, QIODevice::WriteOnly);\n out << this->userid;\n if (m_socket->write(block) == -1) {\n ui->message->append("发送userid失败");\n m_socket->close();\n }\n}\n\nvoid Procession::disconnected()\n{\n ui->message->append("连接失败");\n m_socket->close();\n}\n\nvoid Procession::readyRead()\n{\n QByteArray data = m_socket->readAll();\n if (data.isEmpty()) {\n ui->message->append("读取的数据为空");\n return;\n }\n // 解析服务器返回的数据\n QDataStream in(&data, QIODevice::ReadOnly);\n QString suggestion;\n in >> suggestion; // 使用重载的 >> 运算符来读取数据\n if (in.status() != QDataStream::Ok) {\n ui->message->append("解析服务器返回的数据失败");\n return;\n }\n ui->message->append(suggestion);\n m_socket->close();\n}\n\nvoid Procession::displayError(QAbstractSocket::SocketError error)\n{\n QString errorMessage;\n switch (error) {\n case QAbstractSocket::ConnectionRefusedError:\n errorMessage = "连接被拒绝";\n break;\n case QAbstractSocket::RemoteHostClosedError:\n errorMessage = "远程主机关闭";\n break;\n case QAbstractSocket::HostNotFoundError:\n errorMessage = "未找到主机";\n break;\n case QAbstractSocket::SocketTimeoutError:\n errorMessage = "连接超时";\n break;\n case QAbstractSocket::NetworkError:\n errorMessage = "网络错误";\n break;\n default:\n errorMessage = "未知错误";\n break;\n }\n ui->message->append("连接失败：" + errorMessage);\n