我正在使用 Angular Material md-autocomplete，因为如果没有建议，我正在使用 md-not-found 来显示消息。
我的要求：如果 searchText 的长度小于 3 个字符，如何隐藏 md-not-found。
我尝试了以下代码，但我无法修复。请帮助我。
<!DOCTYPE html>
<html>
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/angular_material/1.0.0/angular-material.min.css">
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular-animate.min.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular-aria.min.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular-messages.min.js"></script>
<!-- Angular Material Library -->
<script src="http://ajax.googleapis.com/ajax/libs/angular_material/1.0.4/angular-material.min.js"></script>
<body>
<div ng-app="myApp" ng-controller="myCtrl">
<p>Country to Select:</p>
<md-content>
<md-autocomplete
ng-disabled="isDisabled"
md-no-cache="noCache"
md-selected-item="selectedItem"
md-search-text="searchText"
md-items="item in searchTextChange(searchText)"
md-item-text="item.country"
placeholder="Which is your favorite Country?">
<md-item-template>
<span md-highlight-text="searchText" md-highlight-flags="^i">{{item.country}}</span>
</md-item-template>
<md-not-found>
No Person matching "{{searchText}}" were found.
</md-not-found>
</md-autocomplete>
</md-content>
<br/>
</div>
<script>
var app = angular.module('myApp', ['ngMaterial']);
app.controller('myCtrl', function ($scope, $http, $q, GetCountryService) {
$scope.searchText = "";
$scope.Person = [];
$scope.selectedItem = [];
$scope.isDisabled = false;
$scope.noCache = false;
$scope.selectedItemChange = function (item) {
//alert("Item Changed");
}
$scope.searchTextChange = function (str) {
return GetCountryService.getCountry(str);
}
});
app.factory('GetCountryService', function ($http, $q) {
return {
getCountry: function(str) {
// the $http API is based on the deferred/promise APIs exposed by the $q service
// so it returns a promise for us by default
var url = "https://www.bbminfo.com/sample.php?token="+str;
return $http.get(url)
.then(function(response) {
if (typeof response.data.records === 'object') {
return response.data.records;
} else {
// invalid response
return $q.reject(response.data.records);
}
}, function(response) {
// something went wrong
return $q.reject(response.data.records);
});
}
};
});
</script>
</body>
</html>