要在字符串模板中做插值操作，需要在你的对象中注入$interpolate服务
$interpolateProvider
<html ng-app="myApp">
<head>
<meta charset="utf-8">
<script src="angular-1.0.1.min.js"></script>
<script type="text/javascript">
var app = angular.module('myApp', []);
app.controller('MyController', function($scope, $interpolate) {
$scope.$watch('emailBody', function(body) {
if (body) {
var template = $interpolate(body);
$scope.previewText =template({to1: $scope.to});
}
});
});
</script>
</head>
<body>
<div ng-controller="MyController">
<input ng-model="to"
type="email"
placeholder="Recipient" />
<textarea ng-model="emailBody"></textarea>
<pre>{{ previewText }}</pre>
</div>
</body>
</html>
