AngularJS | ng要求的指令

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📜 AngularJS | ng要求的指令

📅 最后修改于: 2021-05-13 20:00:33 🧑 作者: Mango

AngularJS中ng必需的指令用于指定HTML元素的必需属性。仅当ng-required指令中的表达式返回true时，才需要表单中的输入字段。，支持它。</p> <p><strong>句法：</strong> </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-cpp" data-lang="C++"><code class="replace"><element ng-required="expression"> Contents... </element> </code></pre> </div> <p><strong>示例1：</strong>本示例使用ng-required指令将form标签的输入文本字段设置为required。 </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-cpp" data-lang="C++"><code class="replace"><!DOCTYPE html> <html> <head> <title>ng-required Directive</title> <script src= "https://ajax.googleapis.com/ajax/libs/angularjs/1.4.2/angular.min.js"> </script> <style> .req { font-size: 90%; font-style: italic; color: red; } </style> </head> <body style="text-align:center"> <h1 style="color:green">GeeksforGeeks</h1> <h2>ng-required Directive</h2> <div ng-app="app" ng-controller="myCtrl"> <form name="myForm"> <p>Enter Your Name: <br/> <span> <input type="text" name="name" ng-model="Name" ng-required ="true" /> </span> </p> <span ng-show="myForm.name.$invalid" class="req"> This is the required field. </span> </form> </div> <script> var app = angular.module("app", []); app.controller("myCtrl", function($scope) { $scope.Name = ""; }); </script> </body> </html> </code></pre> </div> <p><strong>输出：</strong><br/><strong>输入名称之前：</strong> <br/><img alt="要求" class="img-fluid" src="https://mangdo-1254073825.cos.ap-chengdu.myqcloud.com//front_eng_imgs/geeksforgeeks2021/AngularJS%20%7C%20ng-required%20Directive_0.jpg"/><br/><strong>输入名称后：</strong> <br/><img alt="要求" class="img-fluid" src="https://mangdo-1254073825.cos.ap-chengdu.myqcloud.com//front_eng_imgs/geeksforgeeks2021/AngularJS%20%7C%20ng-required%20Directive_1.jpg"/></p> <p><strong>示例2：</strong>本示例在选中复选框后使用ng-required指令创建必填字段。 </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-cpp" data-lang="C++"><code class="replace"><!DOCTYPE html> <html> <head> <title>ng-required Directive</title> <script src= "https://ajax.googleapis.com/ajax/libs/angularjs/1.4.2/angular.min.js"> </script> </head> <body ng-app="app"style="text-align:center"> <h1 style="color:green">GeeksforGeeks</h1> <h2>ng-required Directive</h2> <div ng-controller="geek" style="font-family:arial;"> <form name="myform"> <label for="requiredValue"> Is Required: </label> <input type="checkbox" ng-model="requiredValue" id="required" /> <br><br> <label for="input">Enter Name: </label> <input type="text" ng-model="model" id="input" name="input" ng-required="requiredValue" /> <br> <p style="color:red;" ng-show='myform.input.$error.required'> Name is required </p> </form> </div> <script> var app = angular.module('app', []) app.controller('geek', ['$scope', function($scope) { $scope.requiredValue = true; }]); </script> </body> </html> </code></pre> </div> <p><strong>输出：</strong><br/><strong>在选中复选框之前：</strong> <br/><img alt="要求" class="img-fluid" src="https://mangdo-1254073825.cos.ap-chengdu.myqcloud.com//front_eng_imgs/geeksforgeeks2021/AngularJS%20%7C%20ng-required%20Directive_2.jpg"/><br/><strong>选中复选框后：</strong> <br/><img alt="要求" class="img-fluid" src="https://mangdo-1254073825.cos.ap-chengdu.myqcloud.com//front_eng_imgs/geeksforgeeks2021/AngularJS%20%7C%20ng-required%20Directive_3.jpg"/></p> <div class="_ap_apex_ad" id="82d2079a-8120-480f-9fc7-5cda825d56e7"></div> <p></p></div> </div> </div> </div> </div> </div> <footer> <div class="bg-white text-center pb-1"> <p class="text-body-tertiary pt-3 lh-lg text-opacity-50" id="footer-text">Copyright © 2020 - 2024 版权所有 <br> <a href="https://beian.miit.gov.cn/" target="_blank" class="text-opacity-50 text-body-tertiary mt-1 mb-1">蜀ICP备20006366号-1</a> <br> Made with ❤️ in Chengdu </p> </div> </footer>  <script src="https://unpkg.com/bootstrap@5.3.0-alpha1/dist/js/bootstrap.bundle.min.js" crossorigin="anonymous"></script>  <script src="https://cdn.jsdelivr.net/npm/@meilisearch/instant-meilisearch/dist/instant-meilisearch.umd.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/instantsearch.js@4"></script> <script src="https://www.imangodoc.com/static/javascript/meili_custom.js"></script>  <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/components/prism-core.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/plugins/toolbar/prism-toolbar.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/plugins/autoloader/prism-autoloader.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/plugins/copy-to-clipboard/prism-copy-to-clipboard.min.js"></script> </body> </html>