选择Angularjs中未选择的值

Question

我有这个HTML标记：

    <div ng-repeat="prop in props" style="margin-bottom: 10px;">
  <label class="col-md-4 control-label">Property {{$index + 1}} ({{prop.AddressLine1}})</label><div class="col-md-8">
       <select ng-model="prop.Grade" class="form-control" ng-options="opt.name for opt in propGradings track by opt.id">                                                                       <option ng-selected="{{option.id == prop.Grade}}" ng-repeat="option in propGradings" ng-value="{{option.id}}">{{option.name}}</option>     </select>
   </div>
 </div>

这个静态数组填写下拉列表：

$scope.propGradings = [{ name: "1", id: 1 }, { name: "2", id: 2 }, { name: "3", id: 3 }, { name: "4", id: 4 }];

我可以在下拉列表中加载项目，但我无法根据prop.Grade值预先选择正确的值。

HTML输出：

知道我做错了什么吗？

Answer 1

从下拉列表中选择选项时，键入以进行绑定。使用ng-options时，您可以使用作为将某些内容绑定到模型作为非字符串值。在您的情况下，您可能希望绑定到id的整数值。

语法 select label value array

＆GT; select：绑定到ng-model的值 ＆GT; label：下拉列表中明显显示的价值 ＆GT; value：数组中的当前项目 ＆GT; array：用于生成选项的数据源

绑定到整数值的示例：

var app = angular.module("myApp", []);
app.controller("myCtrl", function ($scope) {
  $scope.props = [{Grade: 1}];
  $scope.propGradings = [{ name: "1", id: 1 }, { name: "2", id: 2 }, { name: "3", id: 3 }, { name: "4", id: 4 }];

});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="myApp" ng-controller="myCtrl">
  Binding with an integer value:
  <div ng-repeat="prop in props" style="margin-bottom: 10px;">
    <label class="col-md-4 control-label">Property {{$index + 1}} ({{prop.AddressLine1}})</label>
    <div class="col-md-8">
      <select ng-model="prop.Grade" class="form-control" ng-options="opt.id as opt.name for opt in propGradings">
        <option ng-selected="{{option.id == prop.Grade}}" ng-repeat="option in propGradings" ng-value="{{option.id}}">{{option.name}}</option>
      </select>
    </div>
  </div>
</div>

绑定到字符串值的示例：

var app = angular.module("myApp", []);
app.controller("myCtrl", function ($scope) {
  $scope.props = [{Grade: "1"}];
  $scope.propGradings = [{ name: "1", id: 1 }, { name: "2", id: 2 }, { name: "3", id: 3 }, { name: "4", id: 4 }];

});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="myApp" ng-controller="myCtrl">
  Binding with a string value:
  <div ng-repeat="prop in props" style="margin-bottom: 10px;">
    <label class="col-md-4 control-label">Property {{$index + 1}} ({{prop.AddressLine1}})</label>
    <div class="col-md-8">
      <select ng-model="prop.Grade" class="form-control" ng-options="opt.name as opt.name for opt in propGradings">
        <option ng-selected="{{option.id == prop.Grade}}" ng-repeat="option in propGradings" ng-value="{{option.id}}">{{option.name}}</option>
      </select>
    </div>
  </div>
</div>