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This article mainly introduces "how to get the boundary point by Qt". In the daily operation, I believe many people have doubts about how to obtain the boundary point by Qt. The editor has consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "how to get the boundary point by Qt". Next, please follow the editor to study!

I. Preface

The acquisition of boundary points is generally used in conjunction with administrative divisions, for example, the user enters the name of a province and city, and then automatically locates it to the province and city, and then obtains the collection of all boundary points from the outline to the js file, and finally for offline use. Another function of obtaining boundary points is to obtain longitude and latitude coordinates such as the lower left corner and upper right corner of the current region, which is mainly used for downloading offline maps. Baidu map provides a good function of bdary.get (cityname, function (rs)) to obtain the collection of boundary points of administrative divisions, where rs.boundaries is the collection of all boundary points. It is estimated that he is the collection of every area stored on the server, and the query returns immediately. Maybe in the early days, it is also manually circled and connected to store to the database. In this way, you can actually set up a program to automatically remove all the collection data of the boundary points of all provinces and cities across the country and use them for offline maps. The test seems to support only the county level, but not the specific townships.

II. Functional features

Both online map and offline map modes are supported.

Support webkit kernel, webengine kernel and IE kernel at the same time.

Multiple dimension points can be set, including name, address, longitude and latitude.

You can set whether the map can be clicked, dragged, or scrolled.

You can set the protocol version, secret key, theme style, central coordinates, central city, geocoding location, and so on.

Can set the map zoom scale and level, thumbnails, scale, road information and other controls visible.

Support map interaction, such as mouse press to get the latitude and longitude of the corresponding location.

Support to query the route, you can set the starting point, end point, route mode, route mode, route scheme (minimum time, least transfer, least walk, do not take the subway, shortest distance, avoid highway).

Can display dots, lines and surfaces tools, and can draw lines, points, rectangles, circles and so on directly on the map.

Administrative divisions can be set up, a certain urban area drawing layer can be specified, and the online map automatically outputs the administrative division boundary points to the js file for offline map use.

Multiple coverings can be added statically or dynamically. Support points, broken lines, polygons, rectangles, circles, arcs, point aggregations, etc.

The function interface is friendly and unified, and it is easy to use, just one class.

Support js dynamic interaction to add points, delete points, clear points, reset points, no need to refresh the page.

Support any Qt version, any system, any compiler.

Third, effect picture

4. Related code void MapBaiDu::getBounds (QStringList & list) {/ / obtain the latitude and longitude of the visual region bssw= lower left corner bsne= upper right corner bsce= center list

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