Question

我试图通过QGeoServiceProvider和QGeoCodingManager使用osm api从给定的物理地址导出纬度和经度。因此我偶然发现了Question，这似乎完全符合我的需要。

但是我想在qt gui应用程序中将其作为一个单独的函数来实现，而且我不会这样做。了解连接中发生了什么。有人可以解释或我如何修改它以使其在函数中工作？

    cout << "Try service: " << "osm" << endl;
    // choose provider
    QGeoServiceProvider qGeoService("osm");
    QGeoCodingManager *pQGeoCoder = qGeoService.geocodingManager();
    if (!pQGeoCoder) {
      cerr
        << "GeoCodingManager '" << "osm"
        << "' not available!" << endl;

    }
    QLocale qLocaleC(QLocale::C, QLocale::AnyCountry);
    pQGeoCoder->setLocale(qLocaleC);
    // build address
    QGeoAddress qGeoAddr;
    qGeoAddr.setCountry(QString::fromUtf8("Germany"));
    qGeoAddr.setPostalCode(QString::fromUtf8("88250"));
    qGeoAddr.setCity(QString::fromUtf8("Weingarten"));
    qGeoAddr.setStreet(QString::fromUtf8("Heinrich-Hertz-Str. 6"));
    QGeoCodeReply *pQGeoCode = pQGeoCoder->geocode(qGeoAddr);
    if (!pQGeoCode) {
      cerr << "GeoCoding totally failed!" << endl;

    }
    cout << "Searching..." << endl;
    QObject::connect(pQGeoCode, &QGeoCodeReply::finished,
      [&qGeoAddr, pQGeoCode](){
        cout << "Reply: " << pQGeoCode->errorString().toStdString() << endl;
        switch (pQGeoCode->error()) {
#define CASE(ERROR) \
case QGeoCodeReply::ERROR: cerr << #ERROR << endl; break
          CASE(NoError);
          CASE(EngineNotSetError);
          CASE(CommunicationError);
          CASE(ParseError);
          CASE(UnsupportedOptionError);
          CASE(CombinationError);
          CASE(UnknownError);
#undef CASE
          default: cerr << "Undocumented error!" << endl;
        }
        if (pQGeoCode->error() != QGeoCodeReply::NoError) return;
        // eval. result
        QList<QGeoLocation> qGeoLocs = pQGeoCode->locations();
        cout << qGeoLocs.size() << " location(s) returned." << endl;
        for (QGeoLocation &qGeoLoc : qGeoLocs) {
          qGeoLoc.setAddress(qGeoAddr);
          QGeoCoordinate qGeoCoord = qGeoLoc.coordinate();
          cout
            << "Lat.:  " << qGeoCoord.latitude() << endl
            << "Long.: " << qGeoCoord.longitude() << endl
            << "Alt.:  " << qGeoCoord.altitude() << endl;
        }
      });

所以我刚删除了QApplication部分，因为我在函数中没有这个引用。结果我得到：

Qt Version: 5.10.0
Try service: osm
Searching...

但没有坐标。我假设与获取lat和lon数据的位置的连接失败。但正如我所提到的，我不明白这里的联系。任何帮助表示赞赏

修改所以我尝试建立一个连接来捕获完成的信号，如建议的那样。代码现在看起来像这样：

QGeoServiceProvider qGeoService("osm");
  QGeoCodingManager *pQGeoCoder = qGeoService.geocodingManager();
  if (!pQGeoCoder) {
    cerr
      << "GeoCodingManager '" << "osm"
      << "' not available!" << endl;

  }
  QLocale qLocaleC(QLocale::C, QLocale::AnyCountry);
  pQGeoCoder->setLocale(qLocaleC);
  // build address
  //QGeoAddress qGeoAddr;
  qGeoAddr.setCountry(QString::fromUtf8("Germany"));
  qGeoAddr.setPostalCode(QString::fromUtf8("88250"));
  qGeoAddr.setCity(QString::fromUtf8("Weingarten"));
  qGeoAddr.setStreet(QString::fromUtf8("Heinrich-Hertz-Str. 6"));
  this->pQGeoCode = pQGeoCoder->geocode(qGeoAddr);
  if (!pQGeoCode) {
    cerr << "GeoCoding totally failed!" << endl;

  }
  cout << "Searching..." << endl;

  connect(pQGeoCode,SIGNAL(finished()),this,SLOT(getlonlat()));

使用Slot：

void MainWindow::getlonlat()
    {
      QList<QGeoLocation> qGeoLocs = pQGeoCode->locations();
                cout << qGeoLocs.size() << " location(s) returned." << endl;
                for (QGeoLocation &qGeoLoc : qGeoLocs) {
                  qGeoLoc.setAddress(qGeoAddr);
                  QGeoCoordinate qGeoCoord = qGeoLoc.coordinate();
                  cout
                    << "Lat.:  " << qGeoCoord.latitude() << endl
                    << "Long.: " << qGeoCoord.longitude() << endl
                    << "Alt.:  " << qGeoCoord.altitude() << endl;
                }
    }

然而，完成的信号没有被触发。因此结果是一样的。的修改

从您的Gui实施代码答案：

MainWindow.cpp：

#include "mainwindow.h"
#include "ui_mainwindow.h"

// standard C++ header:
#include <iostream>
#include <sstream>

// Qt header:
#include <QGeoAddress>
#include <QGeoCodingManager>
#include <QGeoCoordinate>
#include <QGeoLocation>
#include <QGeoServiceProvider>



MainWindow::MainWindow(QWidget *parent) :
  QMainWindow(parent),
  ui(new Ui::MainWindow)
{


  QGeoServiceProvider *pQGeoProvider = nullptr;

  ui->setupUi(this);


  qDebug() << "Qt Version:" << QT_VERSION_STR;
    // main application
    //QApplication app(argc, argv);

    // install signal handlers
    QObject::connect(this->ui->qBtnInit, &QPushButton::clicked,
      [&]() {
        if (pQGeoProvider) delete pQGeoProvider;
        std::ostringstream out;
        pQGeoProvider = init(out);
        log(out.str());
      });
    QObject::connect(this->ui->qBtnFind, &QPushButton::clicked,
      [&]() {
        // init geo coder if not yet done
        if (!pQGeoProvider) {
          std::ostringstream out;
          pQGeoProvider = init(out);
          log(out.str());
          if (!pQGeoProvider) return; // failed
        }
        // fill in request
        QGeoAddress *pQGeoAddr = new QGeoAddress;
        pQGeoAddr->setCountry(this->ui->qTxtCountry->text());
        pQGeoAddr->setPostalCode(this->ui->qTxtZipCode->text());
        pQGeoAddr->setCity(this->ui->qTxtCity->text());
        pQGeoAddr->setStreet(this->ui->qTxtStreet->text());
        QGeoCodeReply *pQGeoCode
          = pQGeoProvider->geocodingManager()->geocode(*pQGeoAddr);
        if (!pQGeoCode) {
          delete pQGeoAddr;
          log("GeoCoding totally failed!\n");
          return;
        }
        { std::ostringstream out;
          out << "Sending request for:\n"
            << pQGeoAddr->country().toUtf8().data() << "; "
            << pQGeoAddr->postalCode().toUtf8().data() << "; "
            << pQGeoAddr->city().toUtf8().data() << "; "
            << pQGeoAddr->street().toUtf8().data() << "...\n";
          log(out.str());
        }
        // install signal handler to process result later
        QObject::connect(pQGeoCode, &QGeoCodeReply::finished,
          [&,pQGeoAddr, pQGeoCode]() {
            // process reply
            std::ostringstream out;
            out << "Reply: " << pQGeoCode->errorString().toStdString() << '\n';
            switch (pQGeoCode->error()) {
              case QGeoCodeReply::NoError: {
                // eval result
                QList<QGeoLocation> qGeoLocs = pQGeoCode->locations();
                out << qGeoLocs.size() << " location(s) returned.\n";
                for (QGeoLocation &qGeoLoc : qGeoLocs) {
                  qGeoLoc.setAddress(*pQGeoAddr);
                  QGeoCoordinate qGeoCoord = qGeoLoc.coordinate();
                  out
                    << "Lat.:  " << qGeoCoord.latitude() << '\n'
                    << "Long.: " << qGeoCoord.longitude() << '\n'
                    << "Alt.:  " << qGeoCoord.altitude() << '\n';
                }
              } break;
  #define CASE(ERROR) \
  case QGeoCodeReply::ERROR: out << #ERROR << '\n'; break
              CASE(EngineNotSetError);
              CASE(CommunicationError);
              CASE(ParseError);
              CASE(UnsupportedOptionError);
              CASE(CombinationError);
              CASE(UnknownError);
  #undef CASE
              default: out << "Undocumented error!\n";
            }
            // log result
            log(out.str());
            // clean-up
            delete pQGeoAddr;
            /* delete sender in signal handler could be lethal
             * Hence, delete it later...
             */
            pQGeoCode->deleteLater();
          });
      });
    // fill in a sample request with a known address initially
    this->ui->qTxtCountry->setText(QString::fromUtf8("Germany"));
    this->ui->qTxtZipCode->setText(QString::fromUtf8("88250"));
    this->ui->qTxtCity->setText(QString::fromUtf8("Weingarten"));
    this->ui->qTxtStreet->setText(QString::fromUtf8("Danziger Str. 3"));


}

MainWindow::~MainWindow()
{
  delete ui;
}


void MainWindow::log(const QString &qString)
{
  this->ui->qTxtLog->setPlainText(this->ui->qTxtLog->toPlainText() + qString);
  this->ui->qTxtLog->moveCursor(QTextCursor::End);
}
void MainWindow::log(const char *text)
{
  log(QString::fromUtf8(text));
}
void MainWindow::log(const std::string &text)
{
  log(text.c_str());
}

QGeoServiceProvider* MainWindow::init(std::ostream &out)
{
  // check for available services
  QStringList qGeoSrvList
    = QGeoServiceProvider::availableServiceProviders();
  for (QString entry : qGeoSrvList) {
    out << "Try service: " << entry.toStdString() << '\n';
    // choose provider
    QGeoServiceProvider *pQGeoProvider = new QGeoServiceProvider(entry);
    if (!pQGeoProvider) {
      out
        << "ERROR: GeoServiceProvider '" << entry.toStdString()
        << "' not available!\n";
      continue;
    }
    QGeoCodingManager *pQGeoCoder = pQGeoProvider->geocodingManager();
    if (!pQGeoCoder) {
      out
        << "ERROR: GeoCodingManager '" << entry.toStdString()
        << "' not available!\n";
      delete pQGeoProvider;
      continue;
    }
    QLocale qLocaleC(QLocale::C, QLocale::AnyCountry);
    pQGeoCoder->setLocale(qLocaleC);
    out << "Using service " << entry.toStdString() << '\n';
    return pQGeoProvider; // success
  }
  out << "ERROR: No suitable GeoServiceProvider found!\n";
  return nullptr; // all attempts failed
}

main.cpp：

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
  QApplication a(argc, argv);
  MainWindow w;
  w.show();

  return a.exec();
}

这里是MainWindow的头文件：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
// standard C++ header:
#include <iostream>
#include <sstream>

// Qt header:

#include <QGeoAddress>
#include <QGeoCodingManager>
#include <QGeoCoordinate>
#include <QGeoLocation>
#include <QGeoServiceProvider>
namespace Ui {
  class MainWindow;
}

class MainWindow : public QMainWindow
{
  Q_OBJECT

public:
  explicit MainWindow(QWidget *parent = 0);
  virtual ~MainWindow();


  void log(const QString &qString);

  void log(const char *text);

  void log(const std::string &text);


  QGeoServiceProvider* init(std::ostream &out);

private:
  Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

Answer 1

我使用GUI将my older sample转换为最小的应用程序：

// standard C++ header:
#include <iostream>
#include <sstream>

// Qt header:
#include <QtWidgets>
#include <QGeoAddress>
#include <QGeoCodingManager>
#include <QGeoCoordinate>
#include <QGeoLocation>
#include <QGeoServiceProvider>

void log(QTextEdit &qTxtLog, const QString &qString)
{
  qTxtLog.setPlainText(qTxtLog.toPlainText() + qString);
  qTxtLog.moveCursor(QTextCursor::End);
}
void log(QTextEdit &qTxtLog, const char *text)
{
  log(qTxtLog, QString::fromUtf8(text));
}
void log(QTextEdit &qTxtLog, const std::string &text)
{
  log(qTxtLog, text.c_str());
}

int main(int argc, char **argv)
{
  qDebug() << "Qt Version:" << QT_VERSION_STR;
  // main application
  QApplication app(argc, argv);
  // setup GUI
  QWidget qWin;
  QVBoxLayout qBox;
  QFormLayout qForm;
  QLabel qLblCountry(QString::fromUtf8("Country:"));
  QLineEdit qTxtCountry;
  qForm.addRow(&qLblCountry, &qTxtCountry);
  QLabel qLblZipCode(QString::fromUtf8("Postal Code:"));
  QLineEdit qTxtZipCode;
  qForm.addRow(&qLblZipCode, &qTxtZipCode);
  QLabel qLblCity(QString::fromUtf8("City:"));
  QLineEdit qTxtCity;
  qForm.addRow(&qLblCity, &qTxtCity);
  QLabel qLblStreet(QString::fromUtf8("Street:"));
  QLineEdit qTxtStreet;
  qForm.addRow(&qLblStreet, &qTxtStreet);
  QLabel qLblProvider(QString::fromUtf8("Provider:"));
  QComboBox qLstProviders;
  qForm.addRow(&qLblProvider, &qLstProviders);
  qBox.addLayout(&qForm);
  QPushButton qBtnFind(QString::fromUtf8("Find Coordinates"));
  qBox.addWidget(&qBtnFind);
  QLabel qLblLog(QString::fromUtf8("Log:"));
  qBox.addWidget(&qLblLog);
  QTextEdit qTxtLog;
  qTxtLog.setReadOnly(true);
  qBox.addWidget(&qTxtLog);
  qWin.setLayout(&qBox);
  qWin.show();
  // initialize Geo Service Providers
  std::vector<QGeoServiceProvider*> pQGeoProviders;
  { std::ostringstream out;
    QStringList qGeoSrvList
      = QGeoServiceProvider::availableServiceProviders();
    for (QString entry : qGeoSrvList) {
      out << "Try service: " << entry.toStdString() << '\n';
      // choose provider
      QGeoServiceProvider *pQGeoProvider = new QGeoServiceProvider(entry);
      if (!pQGeoProvider) {
        out
          << "ERROR: GeoServiceProvider '" << entry.toStdString()
          << "' not available!\n";
        continue;
      }
      QGeoCodingManager *pQGeoCoder = pQGeoProvider->geocodingManager();
      if (!pQGeoCoder) {
        out
          << "ERROR: GeoCodingManager '" << entry.toStdString()
          << "' not available!\n";
        delete pQGeoProvider;
        continue;
      }
      QLocale qLocaleC(QLocale::C, QLocale::AnyCountry);
      pQGeoCoder->setLocale(qLocaleC);
      qLstProviders.addItem(entry);
      pQGeoProviders.push_back(pQGeoProvider);
      out << "Service " << entry.toStdString() << " available.\n";
    }
    log(qTxtLog, out.str());
  }
  if (pQGeoProviders.empty()) qBtnFind.setEnabled(false);
  // install signal handlers
  QObject::connect(&qBtnFind, QPushButton::clicked,
    [&]() {
      // get current geo service provider
      QGeoServiceProvider *pQGeoProvider
        = pQGeoProviders[qLstProviders.currentIndex()];
      // fill in request
      QGeoAddress *pQGeoAddr = new QGeoAddress;
      pQGeoAddr->setCountry(qTxtCountry.text());
      pQGeoAddr->setPostalCode(qTxtZipCode.text());
      pQGeoAddr->setCity(qTxtCity.text());
      pQGeoAddr->setStreet(qTxtStreet.text());
      QGeoCodeReply *pQGeoCode
        = pQGeoProvider->geocodingManager()->geocode(*pQGeoAddr);
      if (!pQGeoCode) {
        delete pQGeoAddr;
        log(qTxtLog, "GeoCoding totally failed!\n");
        return;
      }
      { std::ostringstream out;
        out << "Sending request for:\n"
          << pQGeoAddr->country().toUtf8().data() << "; "
          << pQGeoAddr->postalCode().toUtf8().data() << "; "
          << pQGeoAddr->city().toUtf8().data() << "; "
          << pQGeoAddr->street().toUtf8().data() << "...\n";
        log(qTxtLog, out.str());
      }
      // install signal handler to process result later
      QObject::connect(pQGeoCode, &QGeoCodeReply::finished,
        [&qTxtLog, pQGeoAddr, pQGeoCode]() {
          // process reply
          std::ostringstream out;
          out << "Reply: " << pQGeoCode->errorString().toStdString() << '\n';
          switch (pQGeoCode->error()) {
            case QGeoCodeReply::NoError: {
              // eval result
              QList<QGeoLocation> qGeoLocs = pQGeoCode->locations();
              out << qGeoLocs.size() << " location(s) returned.\n";
              for (QGeoLocation &qGeoLoc : qGeoLocs) {
                qGeoLoc.setAddress(*pQGeoAddr);
                QGeoCoordinate qGeoCoord = qGeoLoc.coordinate();
                out
                  << "Lat.:  " << qGeoCoord.latitude() << '\n'
                  << "Long.: " << qGeoCoord.longitude() << '\n'
                  << "Alt.:  " << qGeoCoord.altitude() << '\n';
              }     
            } break;
#define CASE(ERROR) \
            case QGeoCodeReply::ERROR: out << #ERROR << '\n'; break
            CASE(EngineNotSetError);
            CASE(CommunicationError);
            CASE(ParseError);
            CASE(UnsupportedOptionError);
            CASE(CombinationError);
            CASE(UnknownError);
#undef CASE
            default: out << "Undocumented error!\n";
          }
          // log result
          log(qTxtLog, out.str());
          // clean-up
          delete pQGeoAddr;
          /* delete sender in signal handler could be lethal
           * Hence, delete it later...
           */
          pQGeoCode->deleteLater();
        });
    });
  // fill in a sample request with a known address initially
  qTxtCountry.setText(QString::fromUtf8("Germany"));
  qTxtZipCode.setText(QString::fromUtf8("88250"));
  qTxtCity.setText(QString::fromUtf8("Weingarten"));
  qTxtStreet.setText(QString::fromUtf8("Danziger Str. 3"));
  // runtime loop
  app.exec();
  // done
  return 0;
}

在Windows 10（64位）上的cygwin中进行了编译和测试：

$ g++ --version
g++ (GCC) 6.4.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ qmake-qt5 testQGeoAddressGUI.pro

$ make
g++ -c -fno-keep-inline-dllexport -D_GNU_SOURCE -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_LOCATION_LIB -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_POSITIONING_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I. -isystem /usr/include/qt5 -isystem /usr/include/qt5/QtWidgets -isystem /usr/include/qt5/QtLocation -isystem /usr/include/qt5/QtQuick -isystem /usr/include/qt5/QtGui -isystem /usr/include/qt5/QtPositioning -isystem /usr/include/qt5/QtQml -isystem /usr/include/qt5/QtNetwork -isystem /usr/include/qt5/QtCore -I. -I/usr/lib/qt5/mkspecs/cygwin-g++ -o testQGeoAddressGUI.o testQGeoAddressGUI.cc
g++  -o testQGeoAddressGUI.exe testQGeoAddressGUI.o   -lQt5Widgets -lQt5Location -lQt5Quick -lQt5Gui -lQt5Positioning -lQt5Qml -lQt5Network -lQt5Core -lGL -lpthread 

$ ./testQGeoAddressGUI
Qt Version: 5.9.2

备注：

当我写这个样本时，我非常仔细地考虑了涉及变量的范围和生命周期。（实际上，我将一些局部变量更改为使用new创建的指针和实例来实现此目的。）这是我对任何读者的提示。

在我的1 ^st测试中，应用程序最终在CommunicationError。我很确定我们公司的安全政策是对此负责的。（我对我在家中成功测试的旧样本做了同样的事情 - 结果相同。）

2 ^nd测试（在家里）变得更好。首先，我试图找到服务提供商osm的地址，结果为0。将服务提供商更改为esri会返回一个结果。

我将输出复制到maps.google.de：

这实际上是正确的结果 - 因为我测试了我正在工作的公司EKS InTec的（新）地址。

在上面的示例中使用lambda会使它有点难以阅读。因此，我重新访问了样本。现在，所有相关内容已移至class MainWindow（希望更接近OP的要求）。 lambda被简单的方法所取代。

// standard C++ header: #include <iostream> #include <sstream> // Qt header: #include <QtWidgets> #include <QGeoAddress> #include <QGeoCodingManager> #include <QGeoCoordinate> #include <QGeoLocation> #include <QGeoServiceProvider> // main window class class MainWindow: public QWidget { // variables: private: // list of service providers std::vector<QGeoServiceProvider*> pQGeoProviders; // Qt widgets (contents of main window) QVBoxLayout qBox; QFormLayout qForm; QLabel qLblCountry; QLineEdit qTxtCountry; QLabel qLblZipCode; QLineEdit qTxtZipCode; QLabel qLblCity; QLineEdit qTxtCity; QLabel qLblStreet; QLineEdit qTxtStreet; QLabel qLblProvider; QComboBox qLstProviders; QPushButton qBtnFind; QLabel qLblLog; QTextEdit qTxtLog; // methods: public: // ctor/dtor MainWindow(QWidget *pQParent = nullptr); virtual ~MainWindow(); MainWindow(const MainWindow&) = delete; MainWindow& operator=(const MainWindow&) = delete; private: // internal stuff void init(); // initializes geo service providers void find(); // sends request void report(); // processes reply void log(const QString &qString) { qTxtLog.setPlainText(qTxtLog.toPlainText() + qString); qTxtLog.moveCursor(QTextCursor::End); } void log(const char *text) { log(QString::fromUtf8(text)); } void log(const std::string &text) { log(text.c_str()); } }; MainWindow::MainWindow(QWidget *pQParent): QWidget(pQParent), qLblCountry(QString::fromUtf8("Country:")), qLblZipCode(QString::fromUtf8("Postal Code:")), qLblCity(QString::fromUtf8("City:")), qLblStreet(QString::fromUtf8("Street:")), qLblProvider(QString::fromUtf8("Provider:")), qBtnFind(QString::fromUtf8("Find Coordinates")), qLblLog(QString::fromUtf8("Log:")) { // setup child widgets qForm.addRow(&qLblCountry, &qTxtCountry); qForm.addRow(&qLblZipCode, &qTxtZipCode); qForm.addRow(&qLblCity, &qTxtCity); qForm.addRow(&qLblStreet, &qTxtStreet); qForm.addRow(&qLblProvider, &qLstProviders); qBox.addLayout(&qForm); qBox.addWidget(&qBtnFind); qBox.addWidget(&qLblLog); qBox.addWidget(&qTxtLog); setLayout(&qBox); // init service provider list init(); // install signal handlers QObject::connect(&qBtnFind, &QPushButton::clicked, this, &MainWindow::find); // fill in a sample request with a known address initially qTxtCountry.setText(QString::fromUtf8("Germany")); qTxtZipCode.setText(QString::fromUtf8("88250")); qTxtCity.setText(QString::fromUtf8("Weingarten")); qTxtStreet.setText(QString::fromUtf8("Danziger Str. 3")); } MainWindow::~MainWindow() { // clean-up for (QGeoServiceProvider *pQGeoProvider : pQGeoProviders) { delete pQGeoProvider; } } void MainWindow::init() { // initialize Geo Service Providers { std::ostringstream out; QStringList qGeoSrvList = QGeoServiceProvider::availableServiceProviders(); for (QString entry : qGeoSrvList) { out << "Try service: " << entry.toStdString() << '\n'; // choose provider QGeoServiceProvider *pQGeoProvider = new QGeoServiceProvider(entry); if (!pQGeoProvider) { out << "ERROR: GeoServiceProvider '" << entry.toStdString() << "' not available!\n"; continue; } QGeoCodingManager *pQGeoCoder = pQGeoProvider->geocodingManager(); if (!pQGeoCoder) { out << "ERROR: GeoCodingManager '" << entry.toStdString() << "' not available!\n"; delete pQGeoProvider; continue; } QLocale qLocaleC(QLocale::C, QLocale::AnyCountry); pQGeoCoder->setLocale(qLocaleC); qLstProviders.addItem(entry); pQGeoProviders.push_back(pQGeoProvider); out << "Service " << entry.toStdString() << " available.\n"; } log(out.str()); } if (pQGeoProviders.empty()) qBtnFind.setEnabled(false); } std::string format(const QGeoAddress &qGeoAddr) { std::ostringstream out; out << qGeoAddr.country().toUtf8().data() << "; " << qGeoAddr.postalCode().toUtf8().data() << "; " << qGeoAddr.city().toUtf8().data() << "; " << qGeoAddr.street().toUtf8().data(); return out.str(); } void MainWindow::find() { // get current geo service provider QGeoServiceProvider *pQGeoProvider = pQGeoProviders[qLstProviders.currentIndex()]; // fill in request QGeoAddress qGeoAddr; qGeoAddr.setCountry(qTxtCountry.text()); qGeoAddr.setPostalCode(qTxtZipCode.text()); qGeoAddr.setCity(qTxtCity.text()); qGeoAddr.setStreet(qTxtStreet.text()); QGeoCodeReply *pQGeoCode = pQGeoProvider->geocodingManager()->geocode(qGeoAddr); if (!pQGeoCode) { log("GeoCoding totally failed!\n"); return; } { std::ostringstream out; out << "Sending request for:\n" << format(qGeoAddr) << "...\n"; log(out.str()); } // install signal handler to process result later QObject::connect(pQGeoCode, &QGeoCodeReply::finished, this, &MainWindow::report); /* This signal handler will delete it's own sender. * Hence, the connection need not to be remembered * although it has only a limited life-time. */ } void MainWindow::report() { QGeoCodeReply *pQGeoCode = dynamic_cast<QGeoCodeReply*>(sender()); // process reply std::ostringstream out; out << "Reply: " << pQGeoCode->errorString().toStdString() << '\n'; switch (pQGeoCode->error()) { case QGeoCodeReply::NoError: { // eval result QList<QGeoLocation> qGeoLocs = pQGeoCode->locations(); out << qGeoLocs.size() << " location(s) returned.\n"; for (QGeoLocation &qGeoLoc : qGeoLocs) { QGeoAddress qGeoAddr = qGeoLoc.address(); QGeoCoordinate qGeoCoord = qGeoLoc.coordinate(); out << "Coordinates for " << qGeoAddr.text().toUtf8().data() << ":\n" << "Lat.: " << qGeoCoord.latitude() << '\n' << "Long.: " << qGeoCoord.longitude() << '\n' << "Alt.: " << qGeoCoord.altitude() << '\n'; } } break; #define CASE(ERROR) \ case QGeoCodeReply::ERROR: out << #ERROR << '\n'; break CASE(EngineNotSetError); CASE(CommunicationError); CASE(ParseError); CASE(UnsupportedOptionError); CASE(CombinationError); CASE(UnknownError); #undef CASE default: out << "Undocumented error!\n"; } // log result log(out.str()); // clean-up /* delete sender in signal handler could be lethal * Hence, delete it later... */ pQGeoCode->deleteLater(); } int main(int argc, char **argv) { qDebug() << "Qt Version:" << QT_VERSION_STR; // main application QApplication app(argc, argv); // setup GUI MainWindow win; win.show(); // runtime loop app.exec(); // done return 0; }

注意：

外观和行为与上面的例子相同。我稍微改变了回复的输出。

在准备此示例时，我意识到实际上没有必要设置返回的QGeoLocation的地址，因为它已经存在。恕我直言，有趣的是返回的地址看起来与请求的有点不同。它似乎以（我想说的）标准化形式返回。

如何使用Qt c ++ QGeoServiceProvider从地理地址获取纬度/经度？

1 个答案: