Wechat applet obtains the current location (startlocationupdate, onlocationchange, offlocationchange)

Wechat applet gets the current location

problem

I've been using it wx.getLocation() Method to get the user's location , Discovery is always a matter of chance , Our call frequency is once per second , When doing other business, it will also call , Refer to official documents and find Location document This approach is limited , Wechat restrictions 30 Only one success per second , Other returns fail .

resolvent

Use startLocationUpdate、onLocationChange、offLocationChange Use the three methods together , It can obtain the user's location in real time , And frequent calls do not fail .

Wrapper utility class

//  Underground information location acquisition tool class 

/** *  Get the current location of the user  【 Adapt to the new version of wechat to obtain the location information in the field , used getLocation Frequent method calls have performance problems , also 30 You can only succeed once per second 】 */
const getLocation = () => {
    
    return new Promise((resolve, reject) => {
    
        let _locationChangeFn = (res) => {
    
            resolve(res) //  Send back the location information in the field 
            wx.offLocationChange(_locationChangeFn) //  Turn off real-time positioning 
            wx.stopLocationUpdate(_locationChangeFn); //  lsnrctl stop   If you don't turn off listening , Sometimes it's very slow to get the location 
        }
        wx.startLocationUpdate({
    
            success: (res) => {
    
                wx.onLocationChange(_locationChangeFn)
            },
            fail: (err) => {
    
                //  Regain location permissions 
                wx.openSetting({
    
                    success(res) {
    
                        res.authSetting = {
    
                            "scope.userLocation": true
                        }
                    }
                })
                reject(err)
            }
        })
    })
}

module.exports = {
    
    getLocation
}

call

const locationUtils = require('../../../utils/location') //  Introduce tool classes 
//  Get current location 
locationUtils.getLocation().then(res => {
    
		 console.log(' The latitude and longitude of the current position is ：')
     console.log(res.latitude,res.longitude)
 })