将内容附加到列表时保持滚动位置（AngularJS）答案

【问题标题】：Maintain the scroll position when prepending content to a list (AngularJS)将内容附加到列表时保持滚动位置（AngularJS）
【发布时间】：2015-12-06 19:44:19
【问题描述】：

我一直在尝试使用ng-repeat 将一些项目添加到可滚动容器内的列表中，最近的项目应该位于列表的顶部。如果在添加内容时容器的滚动条不在最顶部，我还需要保持滚动位置。

这是我的解决方案，但我仍有问题。 angular 渲染 dom 中的前置项后总是闪烁。

var myApp = angular.module('myApp', []);

myApp.controller('MainCtrl', function($scope, $interval, $timeout) {
  $scope.items = [];
  $interval(function() {
    var item = {
      id: Math.random(),
      text: (new Date()).toString()
    };
    $scope.items.unshift.apply($scope.items, [item]);

    var $container = $('.stream-container');
    var $topItem = $('.item:first');
    var oScrollTop = $container.scrollTop();
    var oOffset = $topItem.length ? $topItem.position().top : 0;

    $timeout(function() {
      // Executed after the dom has finished rendering
      if ($container.scrollTop() !== 0) {
        $container.scrollTop(oScrollTop + ($topItem.length ? $topItem.position().top : 0) - oOffset);
      }
    });
  }, 1000);
});

.stream-container {
  overflow-y: scroll;
  overflow-x: none;
  height: 100px;
  position: relative;
}

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

<body ng-app="myApp">
  <div class="stream-container" ng-controller="MainCtrl">
    <div class="stream">
      <div class="item" ng-repeat="item in items track by item.id">{{ item.text }}</div>
    </div>
  </div>
</body>

【问题讨论】：

标签： javascript jquery angularjs dom scroll

【解决方案1】：

我找到了this post 并将$timeout 更改为$scope.$$postDigest。现在它按预期工作了。

var myApp = angular.module('myApp', []);

myApp.controller('MainCtrl', function($scope, $interval, $timeout) {
  $scope.items = [];
  $interval(function() {
    var item = {
      id: Math.random(),
      text: (new Date()).toString()
    };
    $scope.items.unshift.apply($scope.items, [item]);

    var $container = $('.stream-container');
    var $topItem = $('.item:first');
    var oScrollTop = $container.scrollTop();
    var oOffset = $topItem.length ? $topItem.position().top : 0;

    $scope.$$postDigest(function() {
      // Executed after the dom has finished rendering
      if ($container.scrollTop() !== 0) {
        $container.scrollTop(oScrollTop + ($topItem.length ? $topItem.position().top : 0) - oOffset);
      }
    });
  }, 1000);
});

.stream-container {
  overflow-y: scroll;
  overflow-x: none;
  height: 100px;
  position: relative;
}

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

<body ng-app="myApp">
  <div class="stream-container" ng-controller="MainCtrl">
    <div class="stream">
      <div class="item" ng-repeat="item in items track by item.id">{{ item.text }}</div>
    </div>
  </div>
</body>

【讨论】：