javascript - ng-selected 不更新下拉列表 angularjs

Question

我一直在使用 AngularJS，在执行以下功能时，作为 select 元素的第一个子元素，我仍然得到一个空选项。

这是我的 HTML 代码片段

<select id="connectTV" aria-label="How many Dish TVs" ng-model="connectTVs.index" ng-change="onChangeMethod(connectTVs.index)" class="selector" aria-required="true">
           <option  ng-repeat="noOfTV in noOfTVs" ng-value="noOfTV.index" ng-selected="noOfTV.index == connectTVs.index">{{noOfTV.value}}</option>
</select>

JS代码

$scope.noOfTVs = [
                      {index: 0, value: 'How many Dish TVs?'},
                      {index: 1, value: 'Connect 1 Dish TV'},
                      {index: 2, value: 'Connect 2 Dish TVs'},
                      {index: 3, value: 'Connect 3 Dish TVs'},
                      {index: 4, value: 'Connect 4 Dish TVs'},
                      {index: 5, value: 'Connect 5 Dish TVs'},
                      {index: 6, value: 'Connect 6 Dish TVs'},
                      {index: 7, value: 'Connect 7 Dish TVs'},
                      {index: 8, value: 'Connect 8 Dish TVs'}
                      ];


$scope.onChangeMethod = function(connectTVsIndex) { 

    // Doing some actions
     $scope.connectTVs = $scope.noOfTVs[connectTVsIndex];
     $window.sessionStorage.setItem("noOfTVSelected", $scope.connectTVs.index);
}

最后，这是生成的 HTML

<option value="? number:4 ?"></option>

获取空选项作为选择元素的第一个子元素。我哪里做错了？有人可以帮忙吗？

Answer 1

您可以使用 ng-options 进行选择而不是 ng-repeat。前者更好performance用于更大的阵列集并提供更大的灵 active 。

var app = angular.module('myApp', [])
app.controller('myCtrl', [
    '$scope',
    function($scope) {
        $scope.noOfTVs = [{
            index: 0,
            value: 'How many Dish TVs?'
        }, {
            index: 1,
            value: 'Connect 1 Dish TV'
        }, {
            index: 2,
            value: 'Connect 2 Dish TVs'
        }, {
            index: 3,
            value: 'Connect 3 Dish TVs'
        }, {
            index: 4,
            value: 'Connect 4 Dish TVs'
        }, {
            index: 5,
            value: 'Connect 5 Dish TVs'
        }, {
            index: 6,
            value: 'Connect 6 Dish TVs'
        }, {
            index: 7,
            value: 'Connect 7 Dish TVs'
        }, {
            index: 8,
            value: 'Connect 8 Dish TVs'
        }];
        $scope.connectTVs=$scope.noOfTVs[0];
        $scope.onChangeMethod = function() {
            // Doing some actions
            console.log($scope.connectTVs)
        }

    }
])

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="myApp">
    <div ng-controller="myCtrl">
        <select id="connectTV" aria-label="How many Dish TVs" ng-model="connectTVs" ng-change="onChangeMethod()" class="selector" aria-required="true" ng-options="noOfTV as noOfTV.value for noOfTV in noOfTVs">
</select>
    </div>
</div>