Qgis二次开发-加载高德在线地图失败报错Raster layer Cannot instantiate the ‘wms‘ data provider_qgis 二次开发加载在线地图

作者：盐析白兔 | 2024-03-14 16:42:20

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qgis 二次开发加载在线地图

1.加载在线的高德地图

以下是在线高德地图地址。

http://webrd01.is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1&style=8

以下是代码示例：


#include <QApplication>
#include <QMainWindow>
#include "qgisinterface.h"
#include "qgsproviderregistry.h"
#include "qgsrasterlayer.h"
#include "qgsproject.h"
#include "qgsmapcanvas.h"
int main(int argc, char *argv[])
{
    // 初始化QGIS
    QgsApplication app(argc, argv, true);
    app.initQgis();
    // 创建主窗口
    QMainWindow mainWindow;
    mainWindow.setWindowTitle("QGIS with Amap");
    // 创建地图Canvas
    QgsMapCanvas* mapCanvas = new QgsMapCanvas(&mainWindow);
    mapCanvas->setCanvasColor(Qt::white);
    mapCanvas->setVisible(true);
    mapCanvas->setFrameStyle(0);
    mainWindow.setCentralWidget(mapCanvas);
    // 创建栅格图层
    QgsRasterLayer* amapLayer = new QgsRasterLayer("http://webrd01.is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1&style=8", "Amap", "wms");
    if (amapLayer->isValid())
    {
        QgsProject::instance()->addMapLayer(amapLayer);
        QgsRectangle extent = amapLayer->extent();
        mapCanvas->setExtent(extent);
    }
    else
    {
        QMessageBox::critical(&mainWindow, "Error", "Could not load Amap layer.");
        return -1;
    }
    // 设置地图范围和投影
    QgsCoordinateReferenceSystem crs("EPSG:3857");
    mapCanvas->setDestinationCrs(crs);
    mapCanvas->enableAntiAliasing(true);
    // 显示主窗口
    mainWindow.show();
    // 执行QGIS事件循环
    return app.exec();
}

结果运行结果无效并报错：

Raster layer Cannot instantiate the 'wms' data provider

大概的意思就是说不能初始化wms的东西，就是wms的相关驱动没有加载好。

解决办法：

1.设置路径


    //设置前缀路径
    QgsApplication app(argc, argv, true);
    app.setPrefixPath("E:/OSGeo4W/apps/qgis-ltr-dev", true);
    app.initQgis();

2.将驱动文件拷贝到运行目录下

不需要设置setPrefixPath()。

将E:/OSGeo4W/apps/qgis-ltr-dev/plugins目录拷贝到生成程序的运行目录下，因为程序启动起来加载的是本地的plugins下的插件。

注意不要拷贝错了，我下载的目录下有两个qgis目录，你使用的哪个路径下的库来编译的程序，就拷贝哪个路径下的plugins目录，否则有可能导致程序起不来。

2.如果url填入不能进行正常加载

提供一个编码url的类


#ifndef QGSXYZCONNECTION_H
#define QGSXYZCONNECTION_H
 
#include <QStringList>
 
struct QgsXyzConnection
{
  QString name;
  QString url;
  int zMin = -1;
  int zMax = -1;
  // Authentication configuration id
  QString authCfg;
  // HTTP Basic username
  QString username;
  // HTTP Basic password
  QString password;
  // Referer
  QString referer;
  // tile pixel ratio (0 = unknown (not scaled), 1.0 = 256x256, 2.0 = 512x512)
  double tilePixelRatio = 0;
  bool hidden = false;
 
  QString encodedUri() const;
};
 
//! Utility class for handling list of connections to XYZ tile layers
class QgsXyzConnectionUtils
{
  public:
    //! Returns list of existing connections, unless the hidden ones
    static QStringList connectionList();
 
    //! Returns last used connection
    static QString selectedConnection();
 
    //! Saves name of the last used connection
    static void setSelectedConnection( const QString &connName );
 
    //! Returns connection details
    static QgsXyzConnection connection( const QString &name );
 
    //! Removes a connection from the list
    static void deleteConnection( const QString &name );
 
    //! Adds a new connection to the list
    static void addConnection( const QgsXyzConnection &conn );
};
 
 
#endif // QGSXYZCONNECTION_H
 
 
 
#include <qgslogger.h>
#include "qgsxyzconnection.h"
 
#include <qgsdatasourceuri.h>
#include <qgssettings.h>
 
QString QgsXyzConnection::encodedUri() const
{
  QgsDataSourceUri uri;
  uri.setParam( QStringLiteral( "type" ), QStringLiteral( "xyz" ) );
  uri.setParam( QStringLiteral( "url" ), url );
  if ( zMin != -1 )
    uri.setParam( QStringLiteral( "zmin" ), QString::number( zMin ) );
  if ( zMax != -1 )
    uri.setParam( QStringLiteral( "zmax" ), QString::number( zMax ) );
  if ( ! authCfg.isEmpty() )
    uri.setAuthConfigId( authCfg );
  if ( ! username.isEmpty() )
    uri.setUsername( username );
  if ( ! password.isEmpty() )
    uri.setPassword( password );
  if ( ! referer.isEmpty() )
    uri.setParam( QStringLiteral( "referer" ), referer );
  if ( tilePixelRatio != 0 )
    uri.setParam( QStringLiteral( "tilePixelRatio" ), QString::number( tilePixelRatio ) );
  return uri.encodedUri();
}
 
QStringList QgsXyzConnectionUtils::connectionList()
{
  QgsSettings settings;
  QStringList connList;
 
  settings.beginGroup( QStringLiteral( "qgis/connections-xyz" ) );
  connList = settings.childGroups();
 
  const QStringList global = settings.globalChildGroups();
  settings.endGroup();
 
  for ( const auto &s : global )
  {
    settings.beginGroup( "qgis/connections-xyz/" + s );
    bool isHidden = settings.value( QStringLiteral( "hidden" ), false ).toBool();
    settings.endGroup();
    if ( isHidden )
    {
      connList.removeOne( s );
    }
  }
 
  return connList;
}
 
QString QgsXyzConnectionUtils::selectedConnection()
{
  QgsSettings settings;
  return settings.value( QStringLiteral( "qgis/connections-xyz/selected" ) ).toString();
}
 
void QgsXyzConnectionUtils::setSelectedConnection( const QString &name )
{
  QgsSettings settings;
  return settings.setValue( QStringLiteral( "qgis/connections-xyz/selected" ), name );
}
 
QgsXyzConnection QgsXyzConnectionUtils::connection( const QString &name )
{
  QgsSettings settings;
  settings.beginGroup( "qgis/connections-xyz/" + name );
 
  QgsXyzConnection conn;
  conn.name = name;
  conn.url = settings.value( QStringLiteral( "url" ) ).toString();
  conn.zMin = settings.value( QStringLiteral( "zmin" ), -1 ).toInt();
  conn.zMax = settings.value( QStringLiteral( "zmax" ), -1 ).toInt();
  conn.authCfg = settings.value( QStringLiteral( "authcfg" ) ).toString();
  conn.username = settings.value( QStringLiteral( "username" ) ).toString();
  conn.password = settings.value( QStringLiteral( "password" ) ).toString();
  conn.referer = settings.value( QStringLiteral( "referer" ) ).toString();
  conn.tilePixelRatio = settings.value( QStringLiteral( "tilePixelRatio" ), 0 ).toDouble();
  conn.hidden = settings.value( QStringLiteral( "hidden" ) ).toBool();
  return conn;
}
 
void QgsXyzConnectionUtils::deleteConnection( const QString &name )
{
  QgsSettings settings;
  settings.remove( "qgis/connections-xyz/" + name );
 
  settings.beginGroup( QStringLiteral( "qgis/connections-xyz" ) );
  QStringList global = settings.globalChildGroups();
 
  if ( global.contains( name ) )
  {
    QgsSettings settings;
    settings.beginGroup( "qgis/connections-xyz/" + name );
    settings.setValue( QStringLiteral( "hidden" ), true );
  }
 
}
 
void QgsXyzConnectionUtils::addConnection( const QgsXyzConnection &conn )
{
  QgsSettings settings;
  bool addHiddenProperty = false;
 
  settings.beginGroup( QStringLiteral( "qgis/connections-xyz" ) );
  QStringList global = settings.globalChildGroups();
  if ( global.contains( conn.name ) )
  {
    addHiddenProperty = true;
  }
  settings.endGroup();
 
  settings.beginGroup( "qgis/connections-xyz/" + conn.name );
  settings.setValue( QStringLiteral( "url" ), conn.url );
  settings.setValue( QStringLiteral( "zmin" ), conn.zMin );
  settings.setValue( QStringLiteral( "zmax" ), conn.zMax );
  settings.setValue( QStringLiteral( "authcfg" ), conn.authCfg );
  settings.setValue( QStringLiteral( "username" ), conn.username );
  settings.setValue( QStringLiteral( "password" ), conn.password );
  settings.setValue( QStringLiteral( "referer" ), conn.referer );
  settings.setValue( QStringLiteral( "tilePixelRatio" ), conn.tilePixelRatio );
  if ( addHiddenProperty )
  {
    settings.setValue( QStringLiteral( "hidden" ), false );
  }
}

使用：


	QgsXyzConnection xyz;
	xyz.url = QStringLiteral("http://webrd01.is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1&style=8");
	xyz.zMin = 0;
	xyz.zMax = 18;
	xyz.tilePixelRatio = 1.0;
 
	QgsXyzConnectionUtils::addConnection(xyz);
 
	QString url2 = xyz.encodedUri();
	qDebug() << "url2 = " << url2;
 
	QgsRasterLayer *layer = addRasterLayerPrivate(url2, QStringLiteral("ocr0"), QStringLiteral("wms"));

3.加载不了的看这里

看了评论有一些同学加载失败，以下是我整理的一个完整例子，加载失败最大的原因，我认为就是Qgis的相关运行库、驱动库没有拷贝完整。我把运行路径也截图了，可以照着参考。

加载高德地图成功效果图

自定义WQgsMapCanvas类


#pragma once
#include <qgsmapcanvas.h>
#include <qgsrasterlayer.h>
#include <QMouseEvent>
#include <QPaintEvent>
#include <qgspoint.h>
#include <qgsmaptoolpan.h>
#include <qgsrubberband.h>
#include <qgsgeometry.h>
#include <QDebug>
#include <QList>
#include <QWheelEvent>
 
 
class WQgsMapCanvas : public QgsMapCanvas
{
	Q_OBJECT
public:
	WQgsMapCanvas(const QString &url,QWidget *parent  = nullptr);
	~WQgsMapCanvas();
 
private:
	QgsRasterLayer *addRasterLayer(const QString &rasterFile, const QString &baseName);
	QgsRasterLayer *addRasterLayerPrivate(const QString &uri, const QString &name, const QString &providerKey);
 
public:
	bool isExistRect = false;
	QRectF qRectf;
 
protected:
	//void wheelEvent(QWheelEvent*event);
 
private:
	QgsRasterLayer *m_layer = nullptr;	//图层
 
};
 
 
 
#include "WQgsMapCanvas.h"
#include <qgsmapcanvas.h>
#include <qgsmaptoolidentify.h>
#include <qgsmaptool.h>
#include <qgssymbollayer.h>
#include <qgsannotationmarkeritem.h>
#include <qgsannotationlayer.h>
#include <qgsmarkersymbollayer.h>
#include <qgssinglesymbolrenderer.h>
#include <qgsrubberband.h>
#include <qgsannotationpointtextitem.h>
#include <qgsmapcanvasannotationitem.h>
#include <qgstextannotation.h>
#include <QTextDocument>
#include "QgsMapToolSelectItem.h"
#include <QRegularExpression>
#include "qgsxyzconnection.h"
#include <qglobal.h>
 
QgsRasterLayer *WQgsMapCanvas::addRasterLayer(const QString &rasterFile, const QString &baseName)
{
	return addRasterLayerPrivate(rasterFile, baseName, QString());
}
 
QgsRasterLayer *WQgsMapCanvas::addRasterLayerPrivate(const QString &uri, const QString &name, const QString &providerKey)
{
	QString shortName = name;
	QRegularExpression reRasterFile(QStringLiteral("^/vsi(.+/)*([^ ]+)( .+)?$"), QRegularExpression::CaseInsensitiveOption);
	QRegularExpressionMatch matchRasterFile = reRasterFile.match(name);
 
	if (matchRasterFile.hasMatch())
	{
		if (!matchRasterFile.captured(2).isEmpty())
		{
			shortName = matchRasterFile.captured(2);
		}
	}
 
	QgsSettings settings;
	QString baseName = settings.value(QStringLiteral("qgis/formatLayerName"), false).toBool() ? QgsMapLayer::formatLayerName(shortName) : shortName;
 
	//QgsDebugMsgLevel("Creating new raster layer using " + uri
	//	+ " with baseName of " + baseName, 2);
 
	QgsRasterLayer *layer = nullptr;
	// XXX ya know QgsRasterLayer can snip out the basename on its own;
	// XXX why do we have to pass it in for it?
	// ET : we may not be getting "normal" files here, so we still need the baseName argument
	if (!providerKey.isEmpty() && uri.endsWith(QLatin1String(".adf"), Qt::CaseInsensitive))
	{
		QFileInfo fileInfo(uri);
		QString dirName = fileInfo.path();
		layer = new QgsRasterLayer(dirName, QFileInfo(dirName).completeBaseName(), QStringLiteral("gdal"));
	}
	else if (providerKey.isEmpty())
		layer = new QgsRasterLayer(uri, baseName); // fi.completeBaseName());
	else
		layer = new QgsRasterLayer(uri, baseName, providerKey);
 
 
	QString title;
	bool ok = false;
 
	if (!layer->isValid())
	{
		QgsError error = layer->error();
		title = "Invalid Layer";
		qDebug() << error.message(QgsErrorMessage::Text);
	}
 
	if (layer)
		layer->loadDefaultMetadata(ok);
 
 
	return layer;
}
 
 
QList<QgsMapLayer *> g_layers;
QList<QgsMapLayer *> g_tempLayer;
bool g_is3857crs = false;
 
WQgsMapCanvas::WQgsMapCanvas(const QString &url,QWidget *parent  /*= nullptr*/)
	: QgsMapCanvas(parent)
{
	setCanvasColor(QColor(255, 255, 255));
	
	QgsRasterLayer *layer = nullptr;
 
	if (url.contains("http"))
	{
		QgsXyzConnection xyz;
		xyz.url = url;
		xyz.zMin = 0;
		xyz.zMax = 18;
		xyz.tilePixelRatio = 1.0;
 
		QgsXyzConnectionUtils::addConnection(xyz);
 
		QString url2 = xyz.encodedUri();
		layer = addRasterLayerPrivate(url2, "OSM", "wms");
		if (!layer->isValid())
		{
			QgsError error = layer->error();
			qDebug() << error.message(QgsErrorMessage::Text);
		}
	}
	else
	{
		layer = new QgsRasterLayer(url); // fi.completeBaseName());
	}
 
	if (!layer->isValid())
	{
		QgsError error = layer->error();
		qDebug() << error.message(QgsErrorMessage::Text);
	}
 
	QgsCoordinateReferenceSystem crs = layer->crs();
	if (crs.authid().contains("3857"))
	{
		g_is3857crs = true;
	}
	qDebug() << "crs = " << crs.authid();
	this->setDestinationCrs(crs);
	g_layers.append(layer);
	g_tempLayer.append(layer);
 
	setExtent(layer->extent());
	enableAntiAliasing(true);
	setLayers(g_layers);
	this->zoomToFullExtent();
	refresh();
}
 
WQgsMapCanvas::~WQgsMapCanvas()
{
 
}

调用：


m_canvas = new WQgsMapCanvas("http://webrd01.is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1&style=8");
 
setCentralWidget(m_canvas);

运行路径截图

剩下的就是qgis运行的动态库了

查看完整的配置： 目录3

https://sunnnnnn666.blog.csdn.net/article/details/131816730

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Qgis二次开发-加载高德在线地图失败报错Raster layer Cannot instantiate the ‘wms‘ data provider_qgis 二次开发 加载在线地图

1.加载在线的高德地图

2.如果url填入不能进行正常加载

3.加载不了的看这里

Qgis二次开发-加载高德在线地图失败报错Raster layer Cannot instantiate the ‘wms‘ data provider_qgis 二次开发加载在线地图