Question

我在移动Ionic应用程序中有一个视图，它定期刷新后台数据。我希望在以下时间停止发生：

此视图不是活动视图
该应用程序在后台

现在我通过以下方式完成这些：

$scope.$on('$ionicView.beforeLeave', pauseUpdates);
$scope.$on('$ionicView.enter', restartUpdates);
document.addEventListener("pause", pauseUpdates, false);
document.addEventListener("resume", restartUpdates, false);

然而，这引入了一个边缘情况，用户进入我的视图，然后返回到另一个视图，将应用程序放在后台，然后切换回它（我重新启动更新，当我不应该）。

在我制作某种isNotCurrentView变量进行跟踪之前 - 我是否完全以错误的方式进行此操作？是否有一些更简洁的方式来跟踪我的状态？我总是暗自觉得使用addEventListener是一种不太强烈的方式来解决这个问题......

Answer 1

After a bit of digging around I've found a more elegant solution to this. As per https://forum.ionicframework.com/t/best-way-to-intercept-events-like-cordova-resume-and-pause-in-ionic/4720/5, a good way to deal with these is to add document-level handlers which fire root-scope broadcasts:

.run(function ($ionicPlatform, $rootScope) {

    $ionicPlatform.ready(function () {
        document.addEventListener("deviceready", onDeviceReady, false);
    });

    function onDeviceReady() {

        console.log('run() -> onDeviceReady');

        document.addEventListener("pause", function (event) {
            console.log('run() -> cordovaPauseEvent');
            $rootScope.$broadcast('cordovaPauseEvent');
        });

        document.addEventListener("resume", function (event) {
            console.log('run() -> cordovaResumeEvent');
            $rootScope.$broadcast('cordovaResumeEvent');
        });
    }
}

Inside your actual controller, you can then handle these like so:

$scope.$on('cordovaPauseEvent', pauseTotalsUpdates);

When the view using your controller is no longer active, Ionic's view caching will keep the controller in memory but will de-activate its $scope. This means that your controller won't run pause/resume events unless it's the active controller. Remember to attach the $on event to $scope and not $rootScope, as that is not detached when your controller goes out of view.

Answer 2

您是否知道可以依赖https://github.com/angular-ui/ui-router/wiki中的 $ stateChangeStart 事件？

因此，您可以在控制器中使用此处理程序保留当前状态/视图：

$rootScope.$on('$stateChangeStart', function (event, toState, toParams, fromState, fromParams) {
...
});

此外，您可以使用cordova-plugin-background-mode来跟踪＆＃34;激活bkg模式等事件＆＃34; （参见onactivate）或＆＃34;从bkg模式恢复＆＃34; （见ondeactivate）。

可靠地检测何时Ionic中的视图无效

2 个答案: