How to use JS and Baidu Maps to implement the map administrative district boundary drawing function

How to use JS and Baidu Maps to implement the map administrative district boundary drawing function, you need specific code examples

Foreword:
In Web development, if you need to Displaying the boundaries of administrative regions can be implemented using JavaScript and Baidu Map API. This article will introduce how to use JS and Baidu Maps to draw administrative district boundaries, and provide specific code examples.

Step 1: Import Baidu Map API
First, import the Baidu Map API script into the HTML page. You can apply for a developer account on the Baidu Map open platform and get your own API key. Then add the following code within the

<script type="text/javascript" src="http://api.map.baidu.com/api?v=3.0&ak=你的API密钥"></script>

In this example, you need to replace "your API key" with your own API key.

Step 2: Create a map container
Create a container for displaying the map in the HTML page. Add the following code within the tag:

<div id="map" style="width: 100%; height: 400px;"></div>

In this example, the map container has an id of "map", a width of 100%, and a height of 400px.

Step 3: Draw administrative district boundaries
Next, implement the function of drawing administrative district boundaries in JavaScript code. Add the following code in the JavaScript code:

// 创建地图实例
var map = new BMap.Map("map");

// 设置地图中心点和缩放级别
var point = new BMap.Point(116.404, 39.915);
map.centerAndZoom(point, 12);

// 行政区划实例化
var district = new BMap.Boundary();

// 获取行政区域
district.get("北京市", function (rs) {
  var count = rs.boundaries.length;
  if (count === 0) {
    alert("未能获取当前输入行政区域");
    return;
  }
  var pointArray = [];
  for (var i = 0; i < count; i++) {
    var ply = new BMap.Polygon(rs.boundaries[i], { strokeWeight: 2, strokeColor: "#ff0000" }); // 创建多边形
    map.addOverlay(ply); // 添加覆盖物
    pointArray = pointArray.concat(ply.getPath());
  }
  map.setViewport(pointArray); // 调整视野
})

In this code, we create a map instance and display it in the specified map container. Then, we set the map's center point and zoom level. Next, through the instance of the BMap.Boundary class, we can get the boundary of the administrative region based on the name of the administrative region. In this example, we obtain the boundaries of "Beijing City" and use red lines to draw the boundaries of the administrative districts.

Finally, we add the drawn borders to the map and adjust the map's view so that all borders are fully displayed.

Step 4: Run the code
After completing the above code, save the HTML file and open it in the browser. You will see a webpage with a map on which the administrative district boundaries of "Beijing City" have been drawn.

Summary:
This article introduces how to use JavaScript and Baidu Map API to realize the function of drawing the boundaries of map administrative areas. By calling the interface provided by Baidu Map API, we can obtain the boundary data of the administrative region and draw it on the map. This allows us to flexibly display and operate administrative region information in web development. I hope the code examples in this article can be helpful to everyone!

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