Using Baidu Map API in PHP to realize the display and control of map scale

Using Baidu Map API in PHP to realize the display and control of map scale

The map scale is a control used to display the scale size of the map on the map. It helps users understand the zoom level and actual value of the map. distance relationship. When developing applications based on Baidu Maps, how to use PHP to display and control the map scale is an important skill. This article will introduce how to use PHP and Baidu Map API to implement the map scale function, and provide corresponding code examples.

First, we need to introduce Baidu Map’s JavaScript library and CSS style files into the HTML page. You can download relevant files from the official website of Baidu Map Open Platform, or use the CDN link directly.

In the above code, we introduced the JavaScript library of Baidu Map API and the CSS style file of the map scale, and created a container div for displaying the map.

Next, we need to write PHP code to initialize the map. In the PHP file, we can use the Map class provided by Baidu Map API to create a map instance and set its scale control.

In the above code, we create a BMap.Map instance and use BMap.Point to set the center point coordinates and zoom level of the map. Then, we created a BMap.ScaleControl instance, added it to the map, and set its display position to the lower left corner of the map (BMAP_ANCHOR_BOTTOM_LEFT).

Run the above code and you will see a Baidu map with a scale on the page.

In addition to adding the scale control when initializing the map, we can also use the addControl method of the map instance to dynamically add and remove the scale control. The following sample code demonstrates how to control the display and hiding of the scale control by clicking a button.

    
    
    
    



    

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In the above code, we added a new button and switched the display and hiding of the scale control by calling the toggleScaleControl function. This function determines the current display state of the scale control by judging its isVisible method, and uses the map's removeControl and addControl methods to implement the display and hide functions.

Through the above sample code, we can use Baidu Map API to display and control the map scale in PHP. Readers can make corresponding modifications and extensions according to their own needs and actual situations to meet the needs of specific applications.

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