Angularjs快速入门（四）-css类和样式

例子：

 .error{background-color:red;}

 .warning{background-color:yellow;}

 <div ng-controller='HeaderController'>
     <div ng-class='{error:isError,warning:isWarning}'>{{messageText}}</div>
     <button ng-click='showError()'>展示error</button>
      <button ng-click='showWarning()'>展示warning</button>
 </div>

 function HeaderController($scope){
   $scope.isError= false;
   $scope.isWarning = false;

   $scope.showError= function(){
     $scope.messageText= 'this is an error!';
     $scope.isError=true;
     $scope.isWarning=false;
 };
    $scope.showWarning = function(){
      $scope.messageText= 'this is an warning!';
     $scope.isError=false;
     $scope.isWarning=true;
 };
 }