1.效果图展示
gif如下所示(文件有点大,已压缩)
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2.demo介绍
- Qt地图插件，使用简单方便，不用浏览器内核，运行高效迅速
- 跨平台支持，（Qt Windows（MinGW, MSVC）\Linux(桌面、嵌入式)\Android\IOS\等)
- 在线更新瓦片地图下载，并且支持缓存保存离线地图实现
- 支持地图转向、旋转、方位调整等,下个版本实现位置地方名搜索
缓存目录如下图所示,当有缓存时,则会获取该缓存目录,否则在线联网更新数据:
3.地图插件介绍
qml提供了四个内建的地图在线插件"esri"、"mapbox"、"nokia"、"osm",但是都不是国内地图,对国内很不友好,本章我们实现一个高德地图插件,我们以osm插件为例,如下所示:
{"Keys": ["osm"],"Provider": "osm","Version": 100,"Experimental": false,"Features": ["OnlineMappingFeature","OnlineGeocodingFeature","ReverseGeocodingFeature","OnlineRoutingFeature","OnlinePlacesFeature"]
}其中"Features"表示该插件支持的哪些特性,比如"OnlineMappingFeature"表示支持在线地图显示、则我们需要实现一个QGeoMappingManagerEngine引擎
每个引擎能支持的所有功能介绍如下所示:
QGeoRoutingManagerEngine
NoRoutingFeatures - Routing is not supported (KO: this option can be omitted)
OnlineRoutingFeature - Online routing support
OfflineRoutingFeature - Offline routing support
LocalizedRoutingFeature - Localized routing support
RouteUpdatesFeature - Support for dynamic path update
AlternativeRoutesFeature - Support for multiple alternative routes
ExcludeAreasRoutingFeature - Support for excluding routing factors
AnyRoutingFeatures - Supports anything your heart desires for routing
QGeoCodingManagerEngine
NoGeocodingFeatures - Geocoding is not supported
OnlineGeocodingFeature - Online geocoding support
OfflineGeocodingFeature - Offline geocoding support
ReverseGeocodingFeature - Reverse geocoding support
LocalizedGeocodingFeature - Localized geocoding support
AnyGeocodingFeatures - All of the above except NoGeocodingFeatures
QGeoMappingManagerEngine
NoMappingFeatures - No mapping supported
OnlineMappingFeature - Support for online maps
OfflineMappingFeature - Support for offline maps
LocalizedMappingFeature - Support for maps with localization
AnyMappingFeatures - All of the above except NoMappingFeatures
QPlaceManagerEngine
NoPlacesFeatures - Point-of-interest is not supported
OnlinePlacesFeature - Online Point-of-interest support
OfflinePlacesFeature - Offline Point-of-interest support
SavePlaceFeature - Support for saving custom points to the map
RemovePlaceFeature - Support for removing Point-of-interes on a map
SaveCategoryFeature - Create and save custom Point-of-interest categories
RemoveCategoryFeature - Remove Point-of-interest categories
PlaceRecommendationsFeature - Support for Recommended Point-of-interest according to keywords
SearchSuggestionsFeature - Suggestions support according to the search query part
LocalizedPlacesFeature - Localization support for Point-of-interes
NotificationsFeature - Support for Point-of-interes change notifications
PlaceMatchingFeature - Support for Point-of-interes comparison from two different providers
AnyPlacesFeatures - It's Time for You to Relax
4.QGeoServiceProviderFactory地图服务插件实现
实现一个QT地图服务插件,我们需要子类化QGeoServiceProviderFactory，以及实现 4个接口虚函数:
QGeoCodingManagerEngine* createGeocodingManagerEngine() : 位置搜索引擎,实现位置地理编码,比如配置文件有"OnlineGeocodingFeature"相关特性,则需要实现该虚函数
QGeoMappingManagerEngine* createMappingManagerEngine() : 地图映射管理器引擎,实现地图显示,比如配置文件有"OnlineMappingFeature"相关特性,则需要实现该虚函数
QGeoRoutingManagerEngine* createRoutingManagerEngine() : 路径规划引擎,实现路径规划,比如配置文件有"OnlineRoutingFeature"相关特性,则需要实现该虚函数
QPlaceManagerEngine* createPlaceManagerEngine() : 位置搜索引擎,实现位置搜索,比如配置文件有"OnlinePlacesFeature"相关特性,则需要实现该虚函数由于本章我们只需要实现一个在线高德地图显示,所以只需要实现QGeoMappingManagerEngine* createMappingManagerEngine()虚函数即可.
自定义一个GeoServiceProviderFactory类,并且继承于QGeoServiceProviderFactory类.
如果不生成dll的话,则需要在main函数中声明插件类:
Q_IMPORT_PLUGIN(GeoServiceProviderFactory)GeoServiceProviderFactory代码如下所示:
class GeoServiceProviderFactory: public QObject, public QGeoServiceProviderFactory
{Q_OBJECTQ_INTERFACES(QGeoServiceProviderFactory)Q_PLUGIN_METADATA(IID "org.qt-project.qt.geoservice.serviceproviderfactory/5.0" FILE "maps_plugin.json")public:QGeoMappingManagerEngine* createMappingManagerEngine (const QVariantMap ¶meters, QGeoServiceProvider::Error *error, QString *errorString) const; // 返回我们子类化的地图映射管理器引擎类
};Q_PLUGIN_METADATA宏用来描述该属性的元信息
IID "org.qt-project.qt.geoservice.serviceproviderfactory/5.0" 则用来描述地图服务的通用接口描述符、
FILE "map_plugin.json" 则标明我们插件的配置描述文件是谁.
map_plugin.json配置文件如下所示:
{"Keys": ["Gaode"],"Provider": "Gaode","Version": 100,"Experimental": false,"Features": ["OnlineMappingFeature","OnlineGeocodingFeature","ReverseGeocodingFeature"]
}假如我们qml去使用Gaode插件,如下所示:
Map {id: _mapanchors.fill: parent// 地图插件plugin: Plugin { name: "Gaode" }}那么就会根据"Gaode"去找到GeoServiceProviderFactory的createMappingManagerEngine虚函数,从而注册一个地图映射管理器引擎给qml显示地图用.
未完待续,具体实现细节参考文章:
61.qt quick-qml高德地图实现V1版本(跨平台支持、无需浏览器内核，运行迅速，下个版本实现位置搜索)_心中无女人 拔刀自然神 剑谱第一页 忘掉心上人-CSDN博客
V2版本文章学习:
63.qt quick-qml使用高德地图插件实现V2版本(新增:位置搜索、路径规划、轨迹编辑等)_获得黑色生命力，抵抗时间扭曲，坚持去做一件有长期有意义的事-CSDN博客
订阅专栏可以走的更远,所有文章都有demo(包括合成大西瓜源码、微信聊天源码、listview拖拽源码等)