Angularjs，如選擇

Question

裏面NG重複填充一定值下拉列表中，我有一個必須要充滿某些選定的值，如果沒有在obj.Name1數據選擇下拉否則應選擇在默認的第一個值選項。

<table ng-controller="TestCtrl"> 

<tr ng-repeat="obj in MainArray" > 
<td>{{$index + 1}}</td> 
<td ng-model="MainArray">{{obj.FirstValue}}</td> 
<td> 

<!-- if obj.Name1 has some value then it has to be selected in select dropdown, else default first value of dropdown must be displayed --> 
<!-- dont know how to put a condition so as to display the obj.Name1 value in the dropdown--> 

<select ng-model="DropdownArray[$index]" ng-options="test.ID as test.Name for test in DropdownList" > 
    <option>Default Value</option> 
</select> 

</table> 

//控制器

.controller('TestCtrl',function($scope, $rootScope, $http, URL, $state, $modal, $interval, Notification){ 



    $scope.DropdownArray=[]; 

    $scope.DropdownList=[ 
{"ID":"1","Name":"one"}, 
{"ID":"2","Name":"two"}, 
{"ID":"3","Name":"three"} 
]; 

    $scope.MainArray=[ 
{"FirstValue":"First","Name1":""} , 
{"FirstValue":"Second","Name1":"two"} , 
{"FirstValue":"Third","Name1":"one"}, 
{"FirstValue":"Forth","Name1":""} 
]; 

}) 

我的問題是，如果obj.Name1包含任何值，我怎麼能顯示它作爲選擇的選項？

Answer 1

您可以匹配一個空字符串，而且由於內部ng-model變量不包含任何它將對空值相匹配的選項，如下所示

<select ng-model="DropdownArray[$index]" ng-options="test.ID as test.Name for test in DropdownList" > 
    <option value="">Default Value</option> 
</select>