用循环遍历数组

Angularjs Iterating through array with loop

本文关键字：数组 遍历 循环      更新时间：2023-09-26

嗨，我是Angularjs的新手，我不知道我在做什么。:)我需要能够在一个文本框中输入一个信用卡号码，然后循环通过找出什么样的信用卡正在使用，并显示该信用卡的图像。到目前为止，我在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>

快速解决方案。如果你需要的话，我以后会改进的。

首先把你的html添加到一个指令模板中，如果现在还没有的话。

输入指令:

<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)
    })
  }
 };
});

现在你可以注意到，每次你在你的输入中输入一些东西，console.log将打印这个值，只要取这个值并做你想做的事情。

看这里

更新

让您久等了。

首先，通过使用正则表达式来检查卡片的类型:

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匹配上述列表中的一个正则表达式。

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
    }
  })
})

上面的代码，正在观察cardNum模型，$watch('cardNum')，每次cardNum的值改变时，$watch范围内的代码将运行。在作用域中有一个forEach循环，它获取每个正则表达式并测试新值。如果存在匹配，则将some字符串赋值给scope.cardType;

指令作用域:

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

cardNum，将具有输入的值。

cardType，将是您的卡的类型。

<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，在这里

一旦你从crdTy得到你的卡的类型，它将是一个字符串，你就可以在这里使用它们:

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>
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