js事件监听

多个html页面监听同一个事件

js封装监听事件

var Evt = {
    callback: [],
    sendEvent: function (key, value) {
        var uuid = this.uuid(8, 16);
        localStorage.setItem('evt_' + key, uuid + '_' + value);
      
    },
    addEvent: function (key, callback) {
        if (this.callback.length > 0) {
            var b = false;
            for (var i in this.callback) {
                var item = this.callback[i];
                if (item.key == key) {
                    this.callback[i].callback = callback;
                    b = true;
                }
            }
            if (!b) {
                var data = { key: key, callback: callback };
                this.callback.push(data);
            }
        } else {
            var data = { key: key, callback: callback };
            this.callback.push(data);
        }

    },

    uuid: function (len, radix) {
        var chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
        var uuid = [], i;
        radix = radix || chars.length;
        if (len) {
            for (i = 0; i < len; i++) uuid[i] = chars[0 | Math.random() * radix];
        } else {
            var r;
            uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
            uuid[14] = '4';
            for (i = 0; i < 36; i++) {
                if (!uuid[i]) {
                    r = 0 | Math.random() * 16;
                    uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
                }
            }
        }

        return uuid.join('');
    }
};
window.addEventListener("storage", function (event) {
    if (event.key.indexOf('evt_') < 0) return;
    var key = event.key.split('_');
    if (Evt.callback.length > 0) {
        for (var j in Evt.callback) {
            if (key[1] == Evt.callback[j].key) {
                var start = event.newValue.indexOf('_') + 1;
                var end = event.newValue.length;
                var value = event.newValue.substring(start, end);
                Evt.callback[j].callback(Evt.callback[j].key, value);
                break;
            }
        }
    }
});

js增加监听事件

Evt.addEvent('missCallNotify', function (key, data) {
    var frontPopup = new Base({ userId: data, key: key });
    frontPopup.missCallNotify()
});

js发送事件（只会向此刻已经打开的页面发送事件，未打开的页面无效）

Evt.sendEvent('missCallNotify', obj.userId);//针对已打开的页面：发送事件

 js监听某个值的变化

 var listenMenuTree = { "value": 1 };
    var i=1;
    setInterval(()=>{
        listenMenuTree.value = i++
    },1000*2)
    Object.defineProperty(listenMenuTree, 'value', {
        get: function (value) {
            // get 和 set 方法
            return value;
        },
        set: function (value) {
            // 当listenMenuTree 的value值发生改变时，触发set函数的内容
            console.log('change',value)
        }
    });