小编典典

如何使用AngularJS绑定到复选框值列表?

javascript

我有几个复选框:

<input type='checkbox' value="apple" checked>
<input type='checkbox' value="orange">
<input type='checkbox' value="pear" checked>
<input type='checkbox' value="naartjie">

我想绑定到控制器中的列表,以便每当更改复选框时,控制器都维护所有检查值的列表,例如['apple', 'pear']

ng-model似乎只能将一个复选框的值绑定到控制器中的变量。

还有另一种方法可以使四个复选框绑定到控制器中的列表吗?


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2020-04-25

共1个答案

小编典典

有两种方法可以解决此问题。使用简单数组或对象数组。每个解决方案都有其优缺点。您会在下面找到每种情况的一种。


用简单的数组作为输入数据

HTML可能如下所示:

<label ng-repeat="fruitName in fruits">
  <input
    type="checkbox"
    name="selectedFruits[]"
    value="{{fruitName}}"
    ng-checked="selection.indexOf(fruitName) > -1"
    ng-click="toggleSelection(fruitName)"
  > {{fruitName}}
</label>

适当的控制器代码为:

app.controller('SimpleArrayCtrl', ['$scope', function SimpleArrayCtrl($scope) {

  // Fruits
  $scope.fruits = ['apple', 'orange', 'pear', 'naartjie'];

  // Selected fruits
  $scope.selection = ['apple', 'pear'];

  // Toggle selection for a given fruit by name
  $scope.toggleSelection = function toggleSelection(fruitName) {
    var idx = $scope.selection.indexOf(fruitName);

    // Is currently selected
    if (idx > -1) {
      $scope.selection.splice(idx, 1);
    }

    // Is newly selected
    else {
      $scope.selection.push(fruitName);
    }
  };
}]);

优点 :简单的数据结构和按名称切换很容易处理

缺点 :添加/删除很麻烦,因为必须管理两个列表(输入和选择)


使用对象数组作为输入数据

HTML可能如下所示:

<label ng-repeat="fruit in fruits">
  <!--
    - Use `value="{{fruit.name}}"` to give the input a real value, in case the form gets submitted
      traditionally

    - Use `ng-checked="fruit.selected"` to have the checkbox checked based on some angular expression
      (no two-way-data-binding)

    - Use `ng-model="fruit.selected"` to utilize two-way-data-binding. Note that `.selected`
      is arbitrary. The property name could be anything and will be created on the object if not present.
  -->
  <input
    type="checkbox"
    name="selectedFruits[]"
    value="{{fruit.name}}"
    ng-model="fruit.selected"
  > {{fruit.name}}
</label>

适当的控制器代码为:

app.controller('ObjectArrayCtrl', ['$scope', 'filterFilter', function ObjectArrayCtrl($scope, filterFilter) {

  // Fruits
  $scope.fruits = [
    { name: 'apple',    selected: true },
    { name: 'orange',   selected: false },
    { name: 'pear',     selected: true },
    { name: 'naartjie', selected: false }
  ];

  // Selected fruits
  $scope.selection = [];

  // Helper method to get selected fruits
  $scope.selectedFruits = function selectedFruits() {
    return filterFilter($scope.fruits, { selected: true });
  };

  // Watch fruits for changes
  $scope.$watch('fruits|filter:{selected:true}', function (nv) {
    $scope.selection = nv.map(function (fruit) {
      return fruit.name;
    });
  }, true);
}]);

优点 :添加/删除非常容易

缺点 :更复杂的数据结构和按名称切换很麻烦或需要辅助方法


2020-04-25