下拉列表中的空字段

Question

这是加载正确 json 数据的 .js 文件，来自 API

   (function() {

      angular.module('application', [])
        .factory('Forecast', ['$http', '$q', function($http, $q) {
            var ApiAddr = "api.com/";
          var forecast = {};

          forecast.getResults = function(timeStart, timeEnd) {
            // We map application varaible names with API param names
            var httpParams = {
              type: "global",
              time: "minute",
              tsmin: timeStart,
              tsmax: timeEnd
            };
            return $http.get(ApiAddr, {
              params: httpParams,
              cache: true
            }).then(function(result) {
              return result.data;
            });
          };

          return forecast;

        }])
        .controller('SampleCtrl', ['$scope', 'Forecast', function($scope, Forecast) {
          $scope.forecastReport = '';

          $scope.getForecast = function() {

            var t1 = Date.parse($scope.timeStart);
            var t2 = Date.parse($scope.timeEnd);

            Forecast.getResults(t1, t2)
              .then(function(report) {
                $scope.result = report;
              }).catch(function(err) {
                $scope.result = '';
                console.error('Unable to fetch forecast report: ' + err);
              });
          };
        }]);

    })();

还有显示结果的HTML文件

<!doctype html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Example</title>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
    <script type="text/javascript" src="js/app.js"></script>
</head>
<body ng-app="application" ng-controller='SampleCtrl'>
    <div ng-controller="SampleCtrl">
        <label>Time Start</label>
            <input type="datetime-local" ng-model='timeStart'></input>
        <label>Time End</label>
            <input type="datetime-local" ng-model='timeEnd'></input>
        <button ng-click="getForecast()">Get Forecast</button>
        <label>Départements</label>
        <select ng-model='selecteditem' ng-options="result.zipcode for dept in result">
            <option value="">-- Choisir département --</option>
        </select>

        <div>
            <b>Forecast result: </b>
        </div>
        <pre>{{selecteditem.count}}</pre>

    </div>
</body>
</html>

问题如下。我输入了两个日期，我得到了正确的 json.

之后，当 json 数据上传时，我有下拉列表，当我点击下拉列表的一个元素（部门的邮政编码）时，我有号码显示的来电数。

但是有一个问题：在下拉菜单中，我总是什么也没写，即使它与 JSON.

中的元素匹配

这是什么原因，如何解决？

我有什么： The empty spaces in the drop down list

The result json output

Answer 1

更改 ng-options 语法如下，因为您在 result

中有对象数组

<select ng-model='selecteditem' ng-options="dept.zipcode as dept.count for dept in result">

Answer 2

错误在 ng-options 中。正确的代码是：

<select ng-model='selecteditem' ng-options="dept.zipcode for dept in result">

Answer 3

连同 ngoptions 试试这个

ng-选项="dep.zipcode as dep.count for dept in result track by result.id"

下拉列表中的空字段

Empty fields in drop-down list

html

angularjs

drop-down-menu

ng-options