Question

我正在使用AngularJS创建一个简单的应用程序网站。

我想在选择中将城市A的值显示为默认选项。

的index.html

<body ng-controller="MainCtrl">
  <select ng-model="selectedCity"  ng-change="extractSubsities(selectedCity)" ng-options="item as item.name for item in cities track by item.name">
  </select>

  <select ng-show="selectedCity.subsities" ng-model="selectedSubCity"  ng-change="extractSubsities(selectedSubCity)" ng-options="item2 as item2.name for item2 in selectedCity.subsities track by item2.name">
   <option style="" value=""></option>
   </select>

  <table>
    <tr ng-repeat="item3 in data track by item3.id">
      <td>{{ item3.id }}</td>
      <td>{{ item3.name }}</td>
      <td>{{ item3.price }}</td>
    </tr>
  </table>

</body>

</html>

这是我的剧本 js ：

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

app.controller('MainCtrl', function($scope) {
  $scope.name = 'World';
  $scope.cities = [
     {
      name: "city A",
      elements: [{
        id: 'c01',
        name: 'name1',
        price: 15
      }, {
        id: 'c02',
        name: 'name2',
        price: 18
      }, {
        id: 'c03',
        name: 'name3',
        price: 11
      }],
      subsities: [ {
          name: "sub A1",
          elements: [{
            id: 'sub01',
            name: 'nameSub1',
            price: 1
          }, {
            id: 'sub02',
            name: 'nameSub2',
            price: 8
          }, {
            id: 'sub03',
            name: 'nameSub3',
            price: 1
          } ]
        },
         {
          name: "sub A2",
          elements: [{
            id: 'ssub01',
            name: 'nameSsub1',
            price: 1
          }, {
            id: 'ssub02',
            name: 'nameSsub2',
            price: 8
          }, {
            id: 'ssub03',
            name: 'nameSsub3',
            price: 4
          } ]
        },
         {
          name: "sub A3",
          elements: [{
            id: 'sssub01',
            name: 'nameSssub1',
            price: 1
          }, {
            id: 'sssub02',
            name: 'nameSssub2',
            price: 2
          }, {
            id: 'sssub03',
            name: 'nameSssub3',
            price: 1
          }]
        }
      ]
    },
     {
      name: "city B",
      elements: [{
        id: 'cc01',
        name: 'name11',
        price: 10
      }, {
        id: 'cc02',
        name: 'name22',
        price: 14
      }, {
        id: 'cc03',
        name: 'name33',
        price: 11
      } ]
    },
    {
      name: "city C",
      elements: [{
        id: 'ccc01',
        name: 'name111',
        price: 19
      }, {
        id: 'ccc02',
        name: 'name222',
        price: 18
      }, {
        id: 'ccc03',
        name: 'name333',
        price: 10
      } ]
    }
  ];
  $scope.extractSubsities = function(itemSelected) {
    if(itemSelected && itemSelected.elements){
        $scope.data = itemSelected.elements;
    } 
  } 

});

我需要将城市A显示为默认选择值我该如何解决这个问题？

Answer 1

您可以在页面完成加载之前通过将此行添加到控制器来设置所选城市。

这样的事情：

$scope.selectedCity = $scope.cities[0].name;

Answer 2

只需将selectedSubCity指定为默认值：

$scope.selectedSubCity = $scope.cities[0];

同时调用extractSubsities：

$scope.extractSubsities();

Answer 3

您可以使用ng-init指令初始化您的选择。此外，您还必须调用extractSubsities()函数来填充表格：

 <select ng-model="selectedCity"  ng-change="extractSubsities(selectedCity)" ng-options="item as item.name for item in cities track by item.name" ng-init="selectedCity = cities[0];extractSubsities(selectedCity)">
  </select>

这是一个有效的fiddle example

我在角度JS中选择的默认选择

3 个答案: