Question

我举一个小例子来提交一个包含用户名和电子邮件的表单。

我想为输入设置一个默认值，如下所示：

＆＃13;

let app = angular.module('myApp', []);

app.controller('myController', function ($scope) {
  let account = {};
  
  // TypeError: Cannot set property 'name' of undefined
  $scope.account.name = 'Hermione'; 

  // TypeError: Cannot set property 'email' of undefined
  $scope.account.email = 'hermione@gmail.com'; 
  
  $scope.form_submit = function ($event, account) {
    $event.preventDefault();
    
    console.log('name', account['name']);
    console.log('email', account['email']);
  };
});

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<form ng-app="myApp" ng-controller="myController">
  <div>
    <label>Name:</label>
    <input type="text" ng-model="account.name" />
  </div>
  
  <div>
    <label>Email:</label>
    <input type="email" ng-model="account.email" />
  </div>
  
  <div>
    <a href="javascript:;" ng-click="form_submit($event, account)">Submit</a>
  </div>
</form>

＆＃13;

错误讯息：

TypeError：无法设置属性＆＃39; name＆＃39;未定义的

或

TypeError：无法设置属性＆＃39; email＆＃39;未定义的

我的第一个问题：我该如何解决？

我也尝试过：用ng-model="account.name"替换ng-model="name"。然后，$scope.name = 'Hermione'。它工作正常。抱歉，我不想这样使用。

第二种情况：我想通过ViewData设置默认值。我试过了：

@{
    // I've set a breakpoint to check value before, ViewData["Name"] is not null
    string name = ViewData["Name"]?.ToString() ?? string.empty;
}

然后：

<input type="text" ng-model="account.name" value="@name" />

该输入始终为空白。

所以，我的第二个问题是：出了什么问题？

p / s：我已提到问题：Cannot set property 'x' of undefined in AngularJs [duplicate]。但它似乎不是我的问题。我无法在那里找到答案。

Answer 1

在您的控制器代码中，在$ scope下定义新对象account，如下所示：

  ....
  // change let account = {}; to the following:
  $scope.account = {};

  // now you could set $scope.acount.name
  $scope.account.name = 'Hermione'; 
  ...

Answer 2

let app = angular.module('myApp', []);

app.controller('myController', function ($scope) {
  var account = {};
  
  // TypeError: Cannot set property 'name' of undefined
  account.name = 'Hermione'; 

  // TypeError: Cannot set property 'email' of undefined
  account.email = 'hermione@gmail.com'; 
  $scope.account=account;
  
  $scope.form_submit = function ($event, account) {
    $event.preventDefault();
    
    console.log('name', account['name']);
    console.log('email', account['email']);
  };
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<form ng-app="myApp" ng-controller="myController">
  <div>
    <label>Name:</label>
    <input type="text" ng-model="account.name" />
  </div>
  
  <div>
    <label>Email:</label>
    <input type="email" ng-model="account.email" />
  </div>
  
  <div>
    <a href="javascript:;" ng-click="form_submit($event, account)">Submit</a>
  </div>
</form>

无法设置属性＆＃39; name＆＃39;来自$ scope.account.name的未定义

2 个答案: