app.js中代码：
App({
//app 全局属性监听 globalData.loading
watch: function (method) {
let that = this
let obj = that.globalData;
Object.defineProperty(obj, "loadState", {
configurable: true,
enumerable: true,
set: function (value) {
method(value);
},
get: function (value) {
return that.loadState;
}
})
},
//注意：改变globalData.loadState时，同时改变loadState
loadState: false,
//全局变量
globalData: {
loadState: false,
}
})
page中代码：
const app = getApp();
Page({
onLoad: function (options) {
app.watch(this.watchBack)
},
//监听事件
watchBack(value) {
console.log(app.globalData)
},
})
