AngularJS语法详解

戚奇略

2023-03-14

本文向大家介绍AngularJS语法详解，包括了AngularJS语法详解的使用技巧和注意事项，需要的朋友参考一下

模板和数据的基本运作流程如下：

用户请求应用起始页面
用户的浏览器向服务器发起一次http连接，然后加载index.html页面，这个页面包含了模板
angular被加载到页面中，等待页面加载完成，查找ng-app指令，用来定义模板的边界
angular遍历模板，查找指定和绑定关系，将触发一些列动作：注册监听器、执行一些DOM操作、从服务器获取初始化数据。最后，应用将会启动起来，并将模板转换成DOM视图
连接到服务器去加载需要展示给用户的其他数据

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一种使用{{}}形式，如{{greeting}} 第二种ng-bind="greeting"

使用第一种，未被渲染的页面可能会被用户看到，index页面建议使用第二种，其余的页面可以使用第一种

表单输入


<html ng-app>

<head>

    <title>表单</title>

    <script type="text/javascript" src="angular.min.js"></script>

    <script type="text/javascript">

    function StartUpController($scope) {

        $scope.funding = {startingEstimate:0};

        computeNeeded = function() {

            $scope.funding.needed = $scope.funding.startingEstimate * 10;

        };

        $scope.$watch('funding.startingEstimate',computeNeeded); //watch model的变化

    }

    </script>

</head>

<body>

    <form ng-controller="StartUpController">

        Starting: <input ng-change="computeNeeded()" ng-model="funding.startingEstimate">  //change的时候调用函数

        Recommendation: {{funding.needed}}

    </form>

</body>

</html>

在某些情况下，我们不想一有变化就立刻做出动作，而是要进行等待。例如：


<html ng-app>

<head>

    <title>表单</title>

    <script type="text/javascript" src="angular.min.js"></script>

    <script type="text/javascript">

    function StartUpController($scope) {

        $scope.funding = {startingEstimate:0};

        computeNeeded = function() {

            $scope.funding.needed = $scope.funding.startingEstimate * 10;

        };

        $scope.$watch('funding.startingEstimate',computeNeeded);//watch监视一个表达式，当这个表达式发生变化时就会调用一个回调函数

        $scope.requestFunding = function() {

            window.alert("Sorry,please get more customers first.")

        };

    }

    </script>

</head>

<body>

    <form ng-submit="requestFunding()" ng-controller="StartUpController">  //ng-submit

        Starting: <input ng-change="computeNeeded()" ng-model="funding.startingEstimate">

        Recommendation: {{funding.needed}}

        <button>Fund my startup!</button>

    </form>

</body>

</html>

非表单提交型的交互，以click为例


<html ng-app>

<head>

    <title>表单</title>

    <script type="text/javascript" src="angular.min.js"></script>

    <script type="text/javascript">

    function StartUpController($scope) {

        $scope.funding = {startingEstimate:0};

        computeNeeded = function() {

            $scope.funding.needed = $scope.funding.startingEstimate * 10;

        };

        $scope.$watch('funding.startingEstimate',computeNeeded);

        $scope.requestFunding = function() {

            window.alert("Sorry,please get more customers first.")

        };

        $scope.reset = function() {

            $scope.funding.startingEstimate = 0;

        };

    }

    </script>

</head>

<body>

    <form ng-controller="StartUpController">

        Starting: <input ng-change="computeNeeded()" ng-model="funding.startingEstimate">

        Recommendation: {{funding.needed}}

        <button ng-click="requestFunding()">Fund my startup!</button>

        <button ng-click="reset()">Reset</button>

    </form>

</body>

</html>

列表、表格以及其他迭代型元素

ng-repeat会通过$index返回当前引用的元素序号。示例代码如下：


<html ng-app>

<head>

    <title>表单</title>

    <script type="text/javascript" src="angular.min.js"></script>

    <script type="text/javascript">

    var students = [{name:'Mary',score:10},{name:'Jerry',score:20},{name:'Jack',score:30}]

    function StudentListController($scope) {

        $scope.students = students;
    }

    </script>

</head>

<body>

    <table ng-controller="StudentListController">

        <tr ng-repeat='student in students'>

            <td>{{$index+1}}</td>

            <td>{{student.name}}</td>

            <td>{{student.score}}</td>

        </tr>

    </table>

</body>

</html>

隐藏与显示
ng-show和ng-hide功能是等价的，但是运行效果正好相反。


<html ng-app>

<head>

<script type="text/javascript" src="angular.min.js"></script>

<script>

  function DeathrayMenuController($scope) {

    $scope.menuState = {show:false };//这里换成menuState.show = false 效果就显示不出来了。以后声明变量还是放在{}里面吧

    $scope.toggleMenu = function() {

      $scope.menuState.show = !$scope.menuState.show;

    };

  }

</script>

</head>

<body>

<div ng-controller='DeathrayMenuController'>

  <button ng-click='toggleMenu()'>Toggle Menu</button>

  <ul ng-show='menuState.show'>

    <li ng-click='stun()'>Stun</li>

    <li ng-click='disintegrate()'>Disintegrate</li>

    <li ng-click='erase()'>Erase from history</li>

  </ul>

</div>   

</body>

</html>

css类和样式

ng-class和ng-style都可以接受一个表达式，表达式执行的结果可能是如下取值之一：

表示css类名的字符串，以空格分隔
css类名数组
css类名到布尔值的映射
代码示例如下：


<html ng-app>

<head>

<style type="text/css">

    .error {

        background-color: red;

    }

    .warning {

        background-color: yellow;

    }

</style>

<script type="text/javascript" src="angular.min.js"></script>

<script>

  function HeaderController($scope) {

    $scope.isError = false;

    $scope.isWarning = false;
    $scope.showError = function() {

        $scope.messageText = "Error!!!!"

        $scope.isError = true;

        $scope.isWarning = false;

    }
    $scope.showWarning = function() {

        $scope.messageText = "Warning!!!"

        $scope.isWarning = true;

        $scope.isError = true;

    }

  }

</script>

</head>

<body>

<div ng-controller="HeaderController">

<div ng-class="{error:isError,warning:isWarning}">{{messageText}}</div>

    <button ng-click="showError()">Error</button>

    <button ng-click="showWarning()">Warning</button>

</div>

</body>

</html>

css类名到布尔值的映射
示例代码如下：


<html ng-app>

<head>

<style type="text/css">

    .selected {

        background-color: lightgreen;

    }

</style>

<script type="text/javascript" src="angular.min.js"></script>

<script>

    function Restaurant($scope) {

        $scope.list = [{name:"The Handsome",cuisine:"BBQ"},{name:"Green",cuisine:"Salads"},{name:"House",cuisine:'Seafood'}];
        $scope.selectRestaurant = function(row) {

            $scope.selectedRow = row;

        }

    }

</script>

</head>

<body>

<table ng-controller="Restaurant">

    <tr ng-repeat='restaurant in list' ng-click='selectRestaurant($index)' ng-class='{selected: $index==selectedRow}'>  //css类名到布尔值的映射,当模型属性selectedRow的值等于ng-repeat中得$index时，selectd样式就会被设置到那一行

        <td>{{restaurant.name}}</td>

        <td>{{restaurant.cuisine}}</td>

    </tr>

</table>

</body>

</html>

AngularJS语法详解

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