Question

我正在创建angular指令，它使用bootstrap表单组包装html输入。我使用ng-change事件来监听更改，但是我在ng-change处理程序中得到旧值。为了显示这一点，我创建了相同的指令，一个使用ng-keyup，另一个使用ng-change事件来监听更改。 / p>

var app = angular.module('app', []);

app.controller('home', function() {
  this.textKeyUp = 'KeyUp';
  this.textNgChange = 'NgChange';
  
  this.textKeyUpChanged = function() {
    console.log('Changed on KeyUp:', this.textKeyUp);
  };
  
  this.textNgChangeChanged = function() {
    console.log('Changed on NgChange:', this.textNgChange);
  };
});

app.directive('apTextKeyUp', function() {
  return {
    controller: function() {},
    controllerAs: 'ctrl',
    bindToController: {
      model: '=',
      change: '&'
    },
    scope: {},
    template: '<input ng-model="ctrl.model" ng-keyup="ctrl.change()" />'
  };
});


app.directive('apTextNgChange', function() {
  return {
    controller: function() {},
    controllerAs: 'ctrl',
    bindToController: {
      model: '=',
      change: '&'
    },
    scope: {},
    template: '<input ng-model="ctrl.model" ng-change="ctrl.change()" />'
  };
});

<!DOCTYPE html>
<html ng-app="app">
  <head>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.5/angular.min.js"></script>
  </head>
  <body ng-controller="home as ctrl">
    <h3>KeyUp</h3>
    <ap-text-key-up model="ctrl.textKeyUp" change="ctrl.textKeyUpChanged()"></ap-text-key-up>
    
    <h3>NgChange</h3>
    <ap-text-ng-change model="ctrl.textNgChange" change="ctrl.textNgChangeChanged()"></ap-text-ng-change>
  </body>
</html>

两个指令都更新模型值，但textNgChangeChanged处理程序值内部尚未更新。

这是设计的吗？我该如何解决这个问题？

Answer 1

当使用Primative类型作为ng-model值时，将在更改值时调用ng-change。由于这是一种主要类型，因此该值尚未传播到homeCtroller。如果您将指令传递给引用对象，那么事情就会按预期工作。

按引用传递文本

＆＃13;

var app = angular.module('app', []);

app.controller('home', function() {
  this.text = {val: 'ABC'};
  this.textChanged = function() {
    console.log('Changed:', this.text.val);
  };
});

app.directive('apText', function() {
  return {
    controller: function() {
      var vm = this;
      vm.onChange = function(){
        console.log(vm.model);
        vm.change();
      };
    },
    controllerAs: 'ctrl',
    bindToController: {
      model: '=',
      change: '&'
    },
    scope: true,
    template: '<input ng-model="ctrl.model.val" ng-change="ctrl.onChange()" />'
  };
});

＆＃13;

<!DOCTYPE html>
<html ng-app="app">

  <head>
    <link rel="stylesheet" href="style.css" />
    <script src="https://code.angularjs.org/1.5.0-rc.0/angular.js"></script>
    <script src="script.js"></script>
  </head>

  <body ng-controller="home as ctrl">
    <ap-text model="ctrl.text" change="ctrl.textChanged()"></ap-text>
  </body>

</html>

＆＃13;

按val

传递文本

＆＃13;

var app = angular.module('app', []);

app.controller('home', function() {
  this.text = 'ABC';
  this.textChanged = function() {
console.log('Changed:', this.text);
  };
});

app.directive('apText', function() {
  return {
controller: function() {
  var vm = this;
  vm.onChange = function(){
    console.log(vm.model);
    vm.change();
  };
},
controllerAs: 'ctrl',
bindToController: {
  model: '=',
  change: '&'
},
scope: true,
template: '<input ng-model="ctrl.model" ng-change="ctrl.onChange()" />'
  };
});

＆＃13;

<!DOCTYPE html>
<html ng-app="app">

  <head>
    <link rel="stylesheet" href="style.css" />
    <script src="https://code.angularjs.org/1.5.0-rc.0/angular.js"></script>
    <script src="script.js"></script>
  </head>

  <body ng-controller="home as ctrl">
    <ap-text model="ctrl.text" change="ctrl.textChanged()"></ap-text>
  </body>

</html>

＆＃13;

Angular ngChange处理程序获取旧值

1 个答案:

按引用传递文本

按val