--@angularJS--浅谈class与Ng-Class的应用

时间:2023-03-08 18:10:40

1、angularjs的表达式是可以写在class里面动态改变其值的,写法如下:

□、CSS1.html:

<!doctype html>
<html ng-app="MyCSSModule">

<head>
    <meta charset="utf-8">
    <link rel="stylesheet" href="CSS1.css">
</head>

<body>
    <div ng-controller="CSSCtrl">
        <p class="text-{{color}}">测试CSS样式</p>                                           //注意这里的class="text-{{color}}"这个class写法,text-后面的angular表达式变量
        <button class="btn btn-default" ng-click="setGreen()">绿色</button>
    </div>
</body>
<script src="js/angular-1.3.0.js"></script>
<script src="CSS1.js"></script>

</html>

□、CSS1.css:

.text-red {
    background-color: #ff0000;
}
.text-green {
    background-color: #00ff00;
}

□、CSS1.js:

var myCSSModule = angular.module('MyCSSModule', []);
myCSSModule.controller('CSSCtrl', ['$scope',
    function($scope) {
        $scope.color = "red";
        $scope.setGreen = function() {                           //定义一个setGreen()方法,点击调用这个方法改变color的值,平谈无奇就这么简单
            $scope.color = "green";
        }
    }
]);

2、上面的例子改造一下,用ng-class,写法如下:

□、NgClass.html:

<!doctype html>
<html ng-app="MyCSSModule">

<head>
    <meta charset="utf-8">
    <link rel="stylesheet" href="NgClass.css">
</head>

<body>
    <div ng-controller='HeaderController'>
        <div ng-class='{error: isError, warning: isWarning}'>{{messageText}}</div>                //注意ng-class='{error: isError, warning: isWarning}'的写法,后面的表达式意为:

当isError为true时,调用error样式类,当isWarning为true时,调用warning样式类
        <button ng-click='showError()'>Simulate Error</button>
        <button ng-click='showWarning()'>Simulate Warning</button>
    </div>
</body>
<script src="js/angular-1.3.0.js"></script>
<script src="NgClass.js"></script>

</html>

□、NgClass.css:

.error {
    background-color: red;
}
.warning {
    background-color: yellow;
}

□、NgClass.js:

var myCSSModule = angular.module('MyCSSModule', []);
myCSSModule.controller('HeaderController', ['$scope',
    function($scope) {
        $scope.isError = false;                                              
        $scope.isWarning = false;                                                       //两个标记变量默认状态下都为false
        $scope.showError = function() {                                             //控制器里面做的事就是给变量赋值,通过html中的ng-click来调用赋值的方法
            $scope.messageText = 'This is an error!';
            $scope.isError = true;
            $scope.isWarning = false;
        };
        $scope.showWarning = function() {
            $scope.messageText = 'Just a warning. Please carry on.';
            $scope.isWarning = true;
            $scope.isError = false;
        };
    }
])