Angularjs用循环遍历数组

Question

您好，我是 Angularjs 的新手，我不知道自己在做什么。 :) 我需要能够在文本框中输入信用卡号，然后遍历以找出正在使用的信用卡类型并显示该信用卡的图像。到目前为止，我的指令中有以下代码。

编辑

app.directive('myDirective', function () {
return {
    restrict: 'E',
    scope: {
        cardNum: '=',
        cardType: '='
    },
    template: '<input ng-model="cardNum"></input>',
    replace: true,
    link: function ($scope, elem, attr) {
        scope.$watch('cardNum', function (val) {
            var regMap = [
                      { id: 'visa', reg: '^4[0-9]{12}(?:[0-9]{3})?$' },
                      { id: 'mastercard', reg: '^5[1-5][0-9]{14}$' },
                      { id: 'discover', reg: '^6(?:011|5[0-9]{2})[0-9]{12}$' },
                      { id: 'amex', reg: '^3[47][0-9]{13}$' }
                    ];

            angular.forEach(regMap, function(e){
                //The current element of the regMap sits in e which is an object `{id:, :reg}`
                if(e.reg.test(val)) {
                    //In the above if you test if the val(which is the input value) is matching the regex `e.reg` and if there is a match you pass the id of the object to a scope variable which was sent into the directive.
                    scope.cardType = e.id
                }
            })
        })

    }
};
});    

<div class="form-group">
                <div class="row">
                    <div class="col-lg-8">                            
                        <label for="CCnum" class="control-label">{{ 'CC_NUMBER' | translate }}</label>
                        <input id="CCnum" name="CCnum" class="form-control" title="Number on the front of your card" required="" type="text" ng-model="crdNo">
                        <!--ve-credit-card-no="vm.ccType"-->
                        <ve-credit-cardno card-num="crdNo" card-type="crdTy"></ve-credit-cardno>
                        {{crdTy}}
                        <div class="error_msg" ng-show="ccform.CCnum.$error.required && submit">Please enter a credit card number</div>

                    </div>
                    <div class="col-lg-3">
                        <label for="ccimg" class="control-label"></label>
                        <span ng-show="crdTy == 'visa'">visa<img id="ccimg" class="img-responsive" src="../../Assets/img/visa.png" /></span>
                        <span ng-show="crdTy == 'mastercard'">mastercard<img id="ccimg" class="img-responsive" src="../../Assets/img/mastercard.png" /></span>
                        <span ng-show="crdTy == 'discover'">discover<img id="ccimg" class="img-responsive" src="../../Assets/img/discover.png" /></span>
                        <span ng-show="crdTy == 'discover'">amex<img id="ccimg" class="img-responsive" src="../../Assets/img/amex.png" /></span>
                    </div>
                </div>
            </div>

Answer 1

快速解决方案。如果你愿意，我稍后会改进它。

首先将您的 html 添加到指令模板中，如果它目前不存在。

模板指令中的输入：

<input ng-model="cardNum">

指令：

app.directive('myDirective', function() {
  return {
  restrict: 'E',
  template: '<input ng-model="cardNum"></input>',
  replace: true,
  link: function($scope, elem, attr) {
    $scope.$watch('cardNum', function(val){
      console.log($scope.cardNum)
    })
  }
 };
});

现在您可以注意到，每次您在输入中输入内容时，console.log 都会打印该值，然后获取该值并使用它做您想做的事情。

看看here

更新

抱歉让您久等了。

首先，您要使用正则表达式检查卡的类型：

var regMap = [
  { id: 'visa', reg: /^4[0-9]{12}(?:[0-9]{3})?$/ }, 
  { id: 'mastercard', reg: /^5[1-5][0-9]{14}$/ }, 
  { id: 'discover', reg: /^6(?:011|5[0-9]{2})[0-9]{12}$/}, 
  { id: 'amex', reg: /^3[47][0-9]{13}$/ }
];

您现在需要做的是检查您的输入是否与上述列表中的一个正则表达式匹配。

scope.$watch('cardNum', function(val){
  //The value of the input sits in `val`
  angular.forEach(regMap, function(e){
    //The current element of the regMap sits in e which is an object `{id:, :reg}`
    if(e.reg.test(val)) {
    //In the above if you test if the val(which is the input value) is matching the regex `e.reg` and if there is a match you pass the id of the object to a scope variable which was sent into the directive.
      scope.cardType = e.id
    }
  })
})

上面这段代码，正在观察cardNum模型，$watch('cardNum')，每次cardNum的值改变时，$watch范围内的代码都会运行。在范围内有一个 forEach 循环，它采用每个正则表达式并测试新值。如果匹配，则将某个字符串分配给 scope.cardType;

指令范围：

scope: {
  cardNum: '=',
  cardType: '='
},

cardNum，将具有输入的值。

cardType，将是您卡的类型。

<input ng-model="crdNo"></input>
<!--Notice how do you send the value of the input, and how you get the card type-->
<my-directive card-num="crdNo" card-type="crdTy"></my-directive>
{{crdTy}}

看看这是如何工作的，here

一旦您从crdTy 获得您的卡片类型，这将是一个字符串，您就可以在此处使用它们：

span ng-show="crdTy == 'visa'">visa<img id="ccimg" class="img-responsive" src="../../Assets/img/visa.png" /></span>
<span ng-show="crdTy == 'mastercard'">mastercard<img id="ccimg" class="img-responsive" src="../../Assets/img/mastercard.png" /></span>
<span ng-show="crdTy == 'discover'">discover<img id="ccimg" class="img-responsive" src="../../Assets/img/discover.png" /></span>
<span ng-show="crdTy == 'discover'">amex<img id="ccimg" class="img-responsive" src="../../Assets/img/amex.png" /></span>