angular小练习,实现简单的笔记保存、读取和删除,并同步剩余字数,其中涉及到了数据存储方面的知识;
html5页面很简单,就是一个文本框,加上三个button分别是保存、读取和删除;
html代码:
<body ng-app="myApp" ng-controller="NoteCtrl"> <h2>我的学习笔记</h2> <textarea cols="30" rows="10" ng-model="msg"></textarea> <div> <button ng-click="save()">保存</button> <button ng-click="read()">读取</button> <button ng-click="remove()">删除</button> </div> <p>剩余的字数:{{getCount()}}</p> <script type="text/javascript" src="../../js/angular-1.5.5/angular.js"></script> <script type="text/javascript" src="app.js"></script> </body>
js代码:
angular.module("myApp",[]) .controller("NoteCtrl",['$scope',function ($scope) { //初始化msg数据 $scope.msg = ""; //定义计算剩余字数的方法 $scope.getCount = function () { //判断用户输入的内容的长度 if($scope.msg.length > 100){ $scope.msg = $scope.msg.slice(0,100); } return 100 - $scope.msg.length; }; //定义保存数据的方法 $scope.save = function () { alert('note has been saved !'); localStorage.setItem("note_key",JSON.stringify($scope.msg)); $scope.msg = ""; }; $scope.read = function () { $scope.msg = JSON.parse(localStorage.getItem("note_key") || "[]");//注意:这里不能是{}也不能是'' }; $scope.remove = function () { localStorage.removeItem("note_key"); $scope.msg = ""; }; }]);