QT管理网络状态和网络连接
参考：http://www.cleartechfei.com/2020/07/qt%E4%BD%BF%E7%94%A8http%E5%8D%8F%E8%AE%AE/
1. 用Qt框架进行应用开发的过程中，很多时候需要进行客户端与服务端的网络通信，需要Qt的internet模块。而网络通信中最常用的协议就是http协议，Qt对http协议的调用进行了封装，使用非常方便。在这总结一下常用的http请求。
使用internet模块时需要在pro文件中添加对应的模块。
QT += network
2. Qt中使用Http协议与服务端通信的请求主要分为GET和POST，GET是从指定的资源请求数据，而POST是向指定的资源提交要被处理的数据。
常用的请求类型包括五类:
2.1. 多个独立参数GET请求
2.2. 参数数组GET请求
2.3. 上传参数数据POST请求
2.4. 上传参数和文件POST请求
2.5. 下载文件GET请求
2.1 多个独立参数GET请求
1 int NormalGetRequest(QString paramer1, QString paramer2) 2 { 3 //生成对应的网络请求 4 QNetworkRequest request; 5 QString scheme = "http"; 6 QString serverAddr = "192.168.0.1"; 7 QString port = "80"; 8 QString requestHeader = scheme + QString("://") + serverAddr + QString(":") + port; 9 QString fullRequest = requestHeader + QString("/api/vi/user/getrequest?paramer1=%1¶mer2=%2").arg(paramer1).arg(paramer2); 10 request.setUrl(QUrl(fullRequest)); 11 12 //发送Get请求 13 QNetworkAccessManager manager; 14 QNetworkReply *reply = manager.get(request); 15 QEventLoop eventLoop; 16 QObject::connect(reply, SIGNAL(finished()),&eventLoop, SLOT(quit())); 17 eventLoop.exec(QEventLoop::ExcludeUserInputEvents); 18 19 //对请求的返回异常进行处理 20 if(reply->error() != QNetworkReply::NoError) 21 { 22 return reply->error(); 23 } 24 25 //解析返回的Json结果 26 QByteArray replyData = reply->readAll(); 27 QJsonParseError json_error; 28 QJsonDocument jsonDoc(QJsonDocument::fromJson(replyData, &json_error)); 29 if(json_error.error != QJsonParseError::NoError) 30 { 31 return -1; 32 } 33 QJsonObject rootObj = jsonDoc.object(); 34 QString codeStr = rootObj.value("code").toString(); 35 if (codeStr.compare("200") == 0) 36 { 37 //返回代码为200的时候证明请求成功对包含的结构数据进行处理 38 if(rootObj.contains("result")) 39 { 40 41 } 42 return 0; 43 } 44 else 45 { 46 //请求失败对对应的处理 47 return codeStr.toInt(); 48 } 49 }
2.2 参数数组GET请求
1 int GetRequestWithArray(QVector<QString> m_filePathVector) 2 { 3 QJsonArray array; 4 for(int index=0; index<m_filePathVector.size(); ++index) 5 { 6 QJsonObject object; 7 object.insert("index",QString::number(index)); 8 object.insert("path",m_filePathVector.at(index)); 9 array.append(object); 10 } 11 12 QJsonDocument document; 13 document.setArray(array); 14 QString arrayString = document.toJson(QJsonDocument::Compact); 15 16 //生成对应的网络请求 17 QNetworkRequest request; 18 QString scheme = "http"; 19 QString serverAddr = "192.168.0.1"; 20 QString port = "80"; 21 QString requestHeader = scheme + QString("://") + serverAddr + QString(":") + port; 22 QString fullRequest = requestHeader + QString("/api/vi/user/getarray?paramers=%1").arg(arrayString); 23 request.setUrl(QUrl(fullRequest)); 24 25 //获取错误 26 QNetworkAccessManager manager; 27 QNetworkReply *reply = manager.get(request); 28 QEventLoop eventLoop; 29 QObject::connect(reply, SIGNAL(finished()),&eventLoop, SLOT(quit())); 30 eventLoop.exec(QEventLoop::ExcludeUserInputEvents); 31 if(reply->error() != QNetworkReply::NoError) 32 { 33 return reply->error(); 34 } 35 36 //解析返回的Json结果 37 QByteArray replyData = reply->readAll(); 38 QJsonParseError json_error; 39 QJsonDocument jsonDoc(QJsonDocument::fromJson(replyData, &json_error)); 40 if(json_error.error != QJsonParseError::NoError) 41 { 42 return -1; 43 } 44 QJsonObject rootObj = jsonDoc.object(); 45 QString codeStr = rootObj.value("code").toString(); 46 if (codeStr.compare("200") == 0) 47 { 48 //返回代码为200的时候证明请求成功对包含的结构数据进行处理 49 if(rootObj.contains("result")) 50 { 51 52 } 53 return 0; 54 } 55 else 56 { 57 //请求失败对对应的处理 58 return codeStr.toInt(); 59 } 60 }
2.3 上传参数数据POST请求
1 int NormalPostRequest(QString paramer1, QString paramer2) 2 { 3 //生成对应的网址请求 4 QNetworkRequest request; 5 QString scheme = "http"; 6 QString serverAddr = "192.168.0.1"; 7 QString port = "80"; 8 QString requestHeader = scheme + QString("://") + serverAddr + QString(":") + port; 9 QString fullRequest = requestHeader + "/api/v1/user/postrequest"; 10 request.setUrl(QUrl(fullRequest)); 11 request.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded"); 12 13 //获取对应的参数数据 14 QByteArray data; 15 data.append("paramer1="); 16 data.append(paramer1.toUtf8()); 17 data.append("¶mer2="); 18 data.append(paramer2.toUtf8()); 19 20 //发送请求 21 QNetworkAccessManager manager; 22 QNetworkReply *reply = manager.post(request,data); 23 QEventLoop eventLoop; 24 QObject::connect(reply, SIGNAL(finished()),&eventLoop, SLOT(quit())); 25 eventLoop.exec(QEventLoop::ExcludeUserInputEvents); 26 if(reply->error() != QNetworkReply::NoError) 27 { 28 return reply->error(); 29 } 30 31 32 //解析返回的Json结果 33 QByteArray replyData = reply->readAll(); 34 QJsonParseError json_error; 35 QJsonDocument jsonDoc(QJsonDocument::fromJson(replyData, &json_error)); 36 if(json_error.error != QJsonParseError::NoError) 37 { 38 return -1; 39 } 40 QJsonObject rootObj = jsonDoc.object(); 41 QString codeStr = rootObj.value("code").toString(); 42 if (codeStr.compare("200") == 0) 43 { 44 //返回代码为200的时候证明请求成功对包含的结构数据进行处理 45 if(rootObj.contains("result")) 46 { 47 48 } 49 return 0; 50 } 51 else 52 { 53 //请求失败对对应的处理 54 return codeStr.toInt(); 55 } 56 }
2.4 上传参数和文件POST请求
1 int PostRequestWithFile(QString paramer1, QString paramer2,QString filePath) 2 { 3 4 //生成对应的网址请求 5 QFileInfo fileInfo(filePath); 6 QString fileName =fileInfo.fileName(); 7 8 QFile* inputFile = new QFile(filePath); 9 inputFile->open(QIODevice::ReadOnly); 10 11 //multipart请求 12 QHttpMultiPart* multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType); 13 //文件块 14 QHttpPart filePart; 15 filePart.setHeader(QNetworkRequest::ContentDispositionHeader, 16 QVariant(QString("form-data; name="uploadfile";filename="%1"").arg(fileName))); 17 filePart.setBodyDevice(inputFile); 18 inputFile->setParent(multiPart); 19 multiPart->append(filePart); 20 21 QHttpPart paramer1Part; 22 paramer1Part.setHeader(QNetworkRequest::ContentDispositionHeader,QVariant("form-data; name="paramer1"")); 23 paramer1Part.setBody(paramer1.toUtf8()); 24 multiPart->append(paramer1Part); 25 26 QHttpPart paramer2Part; 27 paramer2Part.setHeader(QNetworkRequest::ContentDispositionHeader,QVariant("form-data; name="paramer2"")); 28 paramer2Part.setBody(paramer2.toUtf8()); 29 multiPart->append(paramer2Part); 30 31 32 //生成对应的网址请求 33 QNetworkRequest request; 34 QString scheme = "http"; 35 QString serverAddr = "192.168.0.1"; 36 QString port = "80"; 37 QString requestHeader = scheme + QString("://") + serverAddr + QString(":") + port; 38 QString fullRequest = requestHeader + "/api/v1/user/postrequestwithfile"; 39 request.setUrl(QUrl(fullRequest)); 40 41 //发送请求 42 QNetworkAccessManager manager; 43 QNetworkReply *reply = manager.post(request,multiPart); 44 multiPart->setParent(reply); 45 46 QEventLoop eventLoop; 47 QObject::connect(&manager, SIGNAL(finished(QNetworkReply*)),&eventLoop, SLOT(quit())); 48 eventLoop.exec(QEventLoop::ExcludeUserInputEvents); 49 50 if(reply->error() != QNetworkReply::NoError) 51 { 52 return reply->error(); 53 } 54 55 //解析返回的Json结果 56 QByteArray replyData = reply->readAll(); 57 QJsonParseError json_error; 58 QJsonDocument jsonDoc(QJsonDocument::fromJson(replyData, &json_error)); 59 if(json_error.error != QJsonParseError::NoError) 60 { 61 return -1; 62 } 63 QJsonObject rootObj = jsonDoc.object(); 64 QString codeStr = rootObj.value("code").toString(); 65 if (codeStr.compare("200") == 0) 66 { 67 //返回代码为200的时候证明请求成功对包含的结构数据进行处理 68 if(rootObj.contains("result")) 69 { 70 71 } 72 return 0; 73 } 74 else 75 { 76 //请求失败对对应的处理 77 return codeStr.toInt(); 78 } 79 }
2.5 下载文件GET请求
1 int DownloadFileFromWeb(QString fileUrl,QString&fileSavePath) 2 { 3 QNetworkRequest request; 4 QUrl url(fileUrl); 5 QFileInfo fileInfo(url.path()); 6 QString fileName = fileInfo.fileName(); 7 QNetworkAccessManager *accessManager=new QNetworkAccessManager(); 8 request.setUrl(url); 9 QNetworkReply *reply = accessManager->get(request); 10 QEventLoop loop; 11 QObject::connect(accessManager, SIGNAL(finished(QNetworkReply*)), &loop, SLOT(quit())); 12 //如果需要下载进度需要关联对应的信号 13 //connect(reply, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(LoadProgress(qint64, qint64))); 14 loop.exec(QEventLoop::ExcludeUserInputEvents); 15 16 //获取下载返回值 17 QVariant statusCode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute); 18 if (statusCode.toInt() != 200) 19 { 20 return -1; 21 } 22 23 //保存下载的文件 24 QFile file(fileSavePath); 25 if(!file.open(QIODevice::WriteOnly)) 26 { 27 return -2; 28 } 29 file.write(reply->readAll()); 30 file.close(); 31 return 0; 32 }
