如何选择下拉列表angularjs一个选项

问题描述

我使用AngularJS指令，我需要在我的模板设置下拉列表中选择的选项。

I am using AngularJS directive and I need to set a selected option of a dropdown list in my template.

<select id="energySource" ng-options="o.name for o in energyOptions" ng-model="energy" ng-selected="energy" ng-change="energyChange();"></select>

在optionlist的内容取决于资源由当页面加载的服务器发送。

The content of the optionlist depends on resources send by a server when the page is loaded.

var energyChosen = "All";


      angular.element(document).ready(function () {

          $.get('/Dashboard/GetResources', function (data) {

              scope.Resources = data;

              scope.energyOptions = [{ name: scope.Resources.Electricity, id: "Electricity" }, { name: scope.Resources.Gas, id: "Gas" },
               { name: scope.Resources.Water, id: "Water" }, { name: scope.Resources.Solar, id: "Solar" }];

              scope.energy = scope.energyOptions[0];
              energyChosen = scope.energy.id;

              scope.$apply();

          });

它的工作原理，只是一个空的选择是pselected $ P $它消失时，我选择一个选项
我希望能够preSELECT一个选项。我认为

It works except that a blank option is preselected which disappears when i select an optionI would like to be able to preselect one option. I thought that

scope.energy = scope.energyOptions[0];

会做的伎俩，但事实并非如此。我怎么能preSELECT一个选项，在这种情况下？

would do the trick but it didn't. How can i preselect an option in this case ?

推荐答案

你正在做你的 NG选项的方式将选项的名称存储在 scope.energy 不整的选项。你这么做的时候，你在正确的轨道上：

The way you are doing your ng-options it will store the name of the option in scope.energy not the whole option. You were on the right track when you did:

scope.energy = scope.energyOptions[0];

但它不会工作，因为它预计scope.energy是名称，而不是整个选项。你想在你的 NG-选项做的是一样的东西：

<select id="energySource" ng-options="o as on.name for o in energyOptions" ng-model="energy" ng-selected="energy" ng-change="energyChange();"></select>

重要的变化是增加了邻为o.name 。左边的O是将实际被选中并存储在你的 scope.energy ，而为o.name 是将你拉来向下显示的文本。

The important change is the addition of the o as o.name. The 'o' on the left is what will actually be selected and stored in your scope.energy, while the as o.name is the text that will be displayed on your pull down.

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