如何在ng-repeat下拉输入框中添加占位符？

Question

我正在使用ng-repeat实现一个下拉列表。我想在输入框中添加占位符，因为第一次它是空白的（没有选择下拉选项）。所以我想默认设置占位符。我不想留空白下拉输入框。

var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.names = ["Emil", "Tobias", "Linus"];
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<div ng-app="myApp" ng-controller="myCtrl">

<select ng-model="selectedName" ng-options="x for x in names">
</select>

</div>

Answer 1

添加选项

 <select ng-model="selectedName" ng-options="x for x in names">
      <option disabled selected value>Please Select</option>
    </select>

Answer 2

您可以添加选项

<option value="" disabled selected>Please Select</option>

var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.names = ["","Emil", "Tobias", "Linus"];
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<div ng-app="myApp" ng-controller="myCtrl">

<select ng-model="selectedName" ng-options="x for x in names">
<option value="" disabled selected>Please Select</option>
</select>

</div>

Answer 3

您可以在选择中设置默认值uisng ng-init。

var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.names = ["Emil", "Tobias", "Linus"];
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<div ng-app="myApp" ng-controller="myCtrl">

<select ng-init="selectedName = names[0]" 
    ng-model="selectedName" 
    ng-options="x for x in names">
</select>

</div>

Answer 4

你可以这样试试。

var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.names = ["Emil", "Tobias", "Linus"];
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<div ng-app="myApp" ng-controller="myCtrl">

<select ng-model="selectedName" ng-options="x for x in names">
<option value="" selected>Please select</option>
</select>

</div>

Answer 5

此处禁用添加选项：

<option disabled selected value>Select here</option>

代码： https://codepen.io/anon/pen/YYxzxj

var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.names = ["Emil", "Tobias", "Linus"];
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<div ng-app="myApp" ng-controller="myCtrl">

<select ng-model="selectedName" ng-options="x for x in names">
  <option disabled selected value>Select here</option>
</select>

</div>