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ng

window.setInterval的Angular包装形式。Fn是每次延迟时间后被执行的函数。

间隔函数的返回值是一个承诺。这个承诺将在每个间隔刻度被通知,并且到达规定迭代次数后被取消,如果迭代次数未定义,则无限制的执行。通知的值将是运行的迭代次数。取消一个间隔,调用$intreval.cancel(promise)。

备注:当你执行完这项服务后应该把它销毁。特别是当controller或者directive元素被销毁时而$interval未被销毁。你应该考虑到在适当的时候取消interval事件。


用法

$interval(fn,delay,[count],[invokeApply],[Pass]);

参数

参数 类型 描述
fn function() 一个将被反复执行的函数。
delay number 每次调用的间隔毫秒数值。
count number 循环次数的数值,如果没设置,则无限制循环。
invokeApply boolean 如果设置为false,则避开脏值检查,否则将调用$apply。
Pass * 函数的附加参数。

方法

cancel(promise);

取消与承诺相关联的任务。

参数 类型 描述
promise Promise $interval函数的返回值。

实例

<script>
  angular.module('intervalExample', [])
    .controller('ExampleController', ['$scope', '$interval',
      function($scope, $interval) {
        $scope.format = 'M/d/yy h:mm:ss a';
        $scope.blood_1 = 100;
        $scope.blood_2 = 120;

        var stop;
        $scope.fight = function() {
          // Don't start a new fight if we are already fighting
          if ( angular.isDefined(stop) ) return;

          stop = $interval(function() {
            if ($scope.blood_1 > 0 && $scope.blood_2 > 0) {
              $scope.blood_1 = $scope.blood_1 - 3;
              $scope.blood_2 = $scope.blood_2 - 4;
            } else {
              $scope.stopFight();
            }
          }, 100);
        };

        $scope.stopFight = function() {
          if (angular.isDefined(stop)) {
            $interval.cancel(stop);
            stop = undefined;
          }
        };

        $scope.resetFight = function() {
          $scope.blood_1 = 100;
          $scope.blood_2 = 120;
        };

        $scope.$on('$destroy', function() {
          // Make sure that the interval is destroyed too
          $scope.stopFight();
        });
      }])
    // Register the 'myCurrentTime' directive factory method.
    // We inject $interval and dateFilter service since the factory method is DI.
    .directive('myCurrentTime', ['$interval', 'dateFilter',
      function($interval, dateFilter) {
        // return the directive link function. (compile function not needed)
        return function(scope, element, attrs) {
          var format,  // date format
              stopTime; // so that we can cancel the time updates

          // used to update the UI
          function updateTime() {
            element.text(dateFilter(new Date(), format));
          }

          // watch the expression, and update the UI on change.
          scope.$watch(attrs.myCurrentTime, function(value) {
            format = value;
            updateTime();
          });

          stopTime = $interval(updateTime, 1000);

          // listen on DOM destroy (removal) event, and cancel the next UI update
          // to prevent updating time after the DOM element was removed.
          element.on('$destroy', function() {
            $interval.cancel(stopTime);
          });
        }
      }]);
</script>

<div>
  <div ng-controller="ExampleController">
    <label>Date format: <input ng-model="format"></label> <hr/>
    Current time is: <span my-current-time="format"></span>
    <hr/>
    Blood 1 : <font color='red'>{{blood_1}}</font>
    Blood 2 : <font color='red'>{{blood_2}}</font>
    <button type="button" data-ng-click="fight()">Fight</button>
    <button type="button" data-ng-click="stopFight()">StopFight</button>
    <button type="button" data-ng-click="resetFight()">resetFight</button>
  </div>
</div>