Angularjs 双向绑定时字符串的转换成数字类型的问题

作者: 亖呉?盀
来源: 51数据库
2021-08-23

问题：

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<script src="http://www.51sjk.com/Upload/Articles/1/0/287/287963_20210712003557645.js"></script> 
</head>
<body>
<div ng-app="myapp">
<p ng-controller = "mycontrl">结果为 <span ng-bind=""  ></span>
<input type="text" ng-model="first">{{first+second}}
  </p>
</div>
<script>
  var app = angular.module("myapp",[]);
  app.controller("mycontrl",function($scope){
    $scope.first = 5;
    $scope.second =10;
  });
</script>
</body>
</html>

显示结果为

但是，我要是输入50，想要结果为60

因为这个是字符串类型需要转换成数字类型

解决方法：

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<script src="http://www.51sjk.com/Upload/Articles/1/0/287/287963_20210712003557645.js"></script> 
</head>
<body>
<div ng-app="myapp">
<p ng-controller = "mycontrl">结果为 <span ng-bind=""  ></span>
<input type="text" ng-model="first">{{first *1+second*1}}
  </p>
</div>
<script>
  var app = angular.module("myapp",[]);
  app.controller("mycontrl",function($scope){
    $scope.first = 5;
    $scope.second =10;
  });
</script>
</body>
</html>

显示即可正常即是在 {{first *1+second*1}}显示的时候，转换了一下

或者，启用事件监听

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<script src="http://www.51sjk.com/Upload/Articles/1/0/287/287963_20210712003557645.js"></script> 
</head>
<body>
<div ng-app="myapp">
<p ng-controller = "mycontrl">结果为 <span ng-bind=""  ></span>
<input type="text" ng-model="first">{{total}}
  </p>
</div>
<script>
  var app = angular.module("myapp",[]);
  app.controller("mycontrl",function($scope){
    $scope.first = 5;
    $scope.second =10;
    $scope.total = parseint($scope.first)+parseint($scope.second);
    $scope.$watch(function(){
    return $scope.first;
    },function(newvalue,oldvalue){
     if(newvalue != oldvalue){
      $scope.total = parseint($scope.first)+parseint($scope.second);
     }
    });
  });
</script>
</body>
</html>