angularjs - 在条件下使用 NaN

Question

我的模式中有一个分区，我只需要在变量值 $scope.ornamentweightinbank 时显示分区不等于 NaN .

<div class="rows container-fluid" ng-if="ornamentweightinbank!==NaN">

这是处理NaN的常规方式吗？

Answer 1

可以访问JavaScript的原生isNaN通过在 Controller 中的 this 上创建一个类似的函数来实现功能，然后您可以在 ngIf 中访问它像这样的指令:

(function() {

  'use strict';

  angular.module('app', []);

})();

(function() {

  'use strict';

  angular.module('app').controller('MainController', MainController);

  MainController.$inject = ['$scope', '$timeout'];

  function MainController($scope, $timeout) {

    // make isNaN available in your view via controller as syntax
    this.isNaN = function(value) {

      return isNaN(value);

    }

    // set ornamentweightinbank to a number
    $scope.ornamentweightinbank = 10;

    // for demonstrative purposes set ornamentweightinbank to NaN after 5 seconds
    $timeout(function() {

      $scope.ornamentweightinbank = 10 * "test";

    }, 5000);

  }

})()

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.1/angular.min.js"></script>

<div ng-app="app" ng-controller="MainController as MainCtrl">

  <div class="rows container-fluid" ng-if="!MainCtrl.isNaN(ornamentweightinbank)">
    This will show if ornamentweightinbank is not equal to NaN
  </div>

  <div class="rows container-fluid" ng-if="MainCtrl.isNaN(ornamentweightinbank)">
    This will show if ornamentweightinbank is equal to NaN
  </div>

</div>

请参阅this stackoverflow answer为什么不能在表达式中直接使用 isNaN。