uni.onLocationChange is not a function

let systemInfo = uni.getSystemInfoSync();
if (systemInfo.platform === "android") {
let systemSetting = uni.getSystemSetting()
if (systemSetting.locationEnabled === true) {
uni.getLocation({
type: 'wgs84', //返回可以用于uni.openLocation的经纬度
success: (res)=> {
uni.onLocationChange((res)=>{
console.log(res)
})

                    }  
                });  
                // uni.showModal({  
                //  title: '提示',  
                //  content: '是否同意打开GPS定位',  
                //  success: function (res) {  
                //      if (res.confirm) {  
                //          uni.openAppAuthorizeSetting()  
                //      }   
                //  }  
                // });  
            }  

        } else {  
            console.log(777)  
        }调用uni.onLocationChange((res)=>{  
                            console.log(res)  
                        })的时候is not a function坐等领导提醒