更改 getElementsByClassName 的字体大小答案

【问题标题】：change font size for getElementsByClassName更改 getElementsByClassName 的字体大小
【发布时间】：2017-08-27 08:04:55
【问题描述】：

我使用 getElementsByClassName 在页面中删除了一个段落。但是，我无法更改输出的字体大小和颜色。

下面是我要废弃的代码。

var keyPeople1 = tmp.body.getElementsByClassName("cr_profile_people module")[0].children;
for (var i = 0; i < keyPeople1.length; i++) {
  keyPeople1[i].style.fontSize = "2em";
}
$scope.keyPeople = "<div class='cr_profile_people module'><div class='mod_headerBox'>"+keyPeople1[0].innerHTML+"</div><div class='cr_data cr_board'>"+keyPeople1[1].innerHTML+"</div></div>";

for 循环本来是要改变字体大小的，但它不起作用。

html sn-p

<div style="margin: 10px;" ng-bind-html="keyPeople"></div>

在样式<div style="margin: 10px;font-size:60%;"ng-bind-html="keyPeople"></div>中添加字体大小对字体大小没有影响。

请指导更改字体大小和颜色的正确方法。

完整代码

angular js 废弃页面

.controller("companyOwnershipCtrl",function($scope,$http,$ionicLoading,$state,$cashDataFactory){


  $ionicLoading.show();

  $http.get("http://vinn.johnapi.com/wsjapi?url=http://quotes.wsj.com/SG/U11/company-people")
  .success(function(response){
    $ionicLoading.hide();
    var tmp = document.implementation.createHTMLDocument();

    tmp.body.innerHTML = response;

    //Company Info
    var companyInfo1 = tmp.body.getElementsByClassName("cr_profile_contact")[0].children;
    var companyInfo2 = tmp.body.getElementsByClassName("cr_overview_data cr_data")[0].children;

    $scope.companyInfo = "<div class='cr_profile_contact'>"+companyInfo1[0].innerHTML+"</div>";
    $scope.companyInfo += "<div class='cr_overview_data cr_data'>"+companyInfo2[0].innerHTML+"</div>";

    //Description
    var description1 = tmp.body.getElementsByClassName("cr_description_full cr_expand")[0].children;
    $scope.companyDescription = "<p>"+description1[0].innerHTML+"</p>";

    //Key People
    var keyPeople1 = tmp.body.getElementsByClassName("cr_profile_people module")[0].children;
    $scope.keyPeople = "<div class='cr_profile_people module'><div class='mod_headerBox'>"+keyPeople1[0].innerHTML+"</div><div class='cr_data cr_board'>"+keyPeople1[1].innerHTML+"</div></div>";

    //Average Growth Rates
    var growth = tmp.body.getElementsByClassName("cr_profile_growth module")[0].children;
    var growth1 = tmp.body.getElementsByClassName("cr_profile_insider module")[0].children;
    $scope.averageGrowthRates = "<div class='cr_profile_growth module'><div class='mod_headerBox'>"+growth[0].innerHTML+"</div><div class='cr_data'>"+growth[1].innerHTML+"</div></div>";
    $scope.averageGrowthRates += "<div class='cr_profile_insider module'><div class='mod_headerBox'>"+growth1[0].innerHTML+"</div><div class='cr_data'>"+growth1[1].innerHTML+"</div><div class='cr_data'>"+growth1[2].innerHTML+"</div></div>";

    //ownership
    var ownership = tmp.body.getElementsByClassName("cr_profile_ownership module")[0].children;
    $scope.averageGrowthRates += "<div class='cr_profile_ownership module'><div class='mod_headerBox'>"+ownership[0].innerHTML+"</div><div class='cr_data'>"+ownership[1].innerHTML+"</div><div class='cr_data'>"+ownership[2].innerHTML+"</div></div>";
  }).error(function(error){

    $ionicLoading.hide();
    console.log(error.data);

  });

html

<ion-view view-title="Company">
  <ion-nav-buttons side="left">
  </ion-nav-buttons>
<ion-content id="comp">
  <ion-scroll>
    <h3 style="margin: 10px;">Company Info</h3>
    <div style="margin: 10px;" ng-bind-html="companyInfo"></div>
    <h3 style="margin: 10px;">Description</h3>
    <div style="margin: 10px;font-size:20px;" ng-bind-html="companyDescription"></div>
    <div style="margin: 10px;color:#AAAFFF;font-size:40px;" ng-bind-html="keyPeople"></div>s   
    <div style="margin: 10px;" ng-bind-html="averageGrowthRates"></div>
    <div style="margin: 10px;" ng-bind-html="ownership"></div>
  </ion-scroll>
</ion-content>
</ion-view>

更新： 使用@Manzurul 和@Varun Sukheja 的当前答案。

我画的红框内的字体大小和颜色都没有生效
红框下方的表格字体大小不生效，只是颜色改变了。

所以，我很好奇为什么红框内的字体大小无法更改？更重要的是如何改变它。

图片正在使用

.controller("companyOwnershipCtrl",function($scope,$http,$ionicLoading,$state,$cashDataFactory){

$scope.companyDescriptionStyle = {"color": "blue", "font-size": "40px"};

在angularjs和<div style="margin: 10px;font-size:20px;" ng-bind-html="companyDescription" ng-style="companyDescriptionStyle"></div>在html中，但是你可以注意到字体大小和上面一样。

从此链接中报废的html代码http://quotes.wsj.com/SG/U11/company-people

<div class="cr_profile_people module"> <div class="mod_headerBox"> <h3>Key People <span class="hdr_co_name">United Overseas Bank Ltd.</span></h3> </div> <div class="cr_data cr_board"> <h4>Board of Directors</h4> <table class="cr_dataTable cr_board_table"> <tbody> <tr> <th>Name/Title</th> <th>Current Board Membership</th> </tr> </tbody> </table> <div class="scrollBox"> <table class="cr_dataTable cr_board_table"> <tbody> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86291589">Ee Cheong Wee</a>, <span class="data_meta">63</span> </span> <span class="data_lbl">Deputy Chairman &amp; Chief Executive Officer</span> </td> <td> <span class="data_lbl">PT Bank UOB Indonesia, Visa International Senior Client Council, United Overseas Bank Ltd., Singapore-China Foundation Ltd., Far Eastern Bank Ltd., United Overseas Insurance Ltd., United Overseas Bank (Thai) Public Co. Ltd., United Overseas Bank (Malaysia) Bhd., The Institute of Banking &amp; Finance, United Overseas Bank (China) Ltd., Wee Foundation, United Overseas Bank Ltd. (Singapore)</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/16055509">Michael Lien</a>, <span class="data_meta"></span> </span> <span class="data_lbl">Non-Executive Director</span> </td> <td> <span class="data_lbl">United Overseas Bank Ltd. (Singapore)</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/104206">Cho Yaw Wee</a>, <span class="data_meta">88</span> </span> <span class="data_lbl">Chairman-Emeritus</span> </td> <td> <span class="data_lbl">United Overseas Bank Ltd. (Singapore)</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/16489539">Fu Hua Hsieh</a>, <span class="data_meta">66</span> </span> <span class="data_lbl">Chairman</span> </td> <td> <span class="data_lbl">United Overseas Bank Ltd. (Singapore)</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86320739">Khirn Hai Yeo</a>, <span class="data_meta">55</span> </span> <span class="data_lbl">Independent Non-Executive Director</span> </td> <td> <span class="data_lbl">United Overseas Bank Ltd. (Singapore)</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/154674047">Kan Seng Wong</a>, <span class="data_meta">71</span> </span> <span class="data_lbl">Independent Non-Executive Director</span> </td> <td> <span class="data_lbl">United Overseas Bank Ltd. (Singapore)</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/13470908">Alexander Charles Hungate</a>, <span class="data_meta">51</span> </span> <span class="data_lbl">Independent Non-Executive Director</span> </td> <td> <span class="data_lbl">United Overseas Bank Ltd. (Singapore)</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/98308786">Hwee Hua Lim</a>, <span class="data_meta">57</span> </span> <span class="data_lbl">Independent Non-Executive Director</span> </td> <td> <span class="data_lbl">United Overseas Bank Ltd. (Singapore), BW Group Ltd., Jardine Cycle &amp; Carriage Ltd., Stewardship &amp; Corporate Governance Centre Pte Ltd., PAP Community Foundation, Stewardship Asia Centre Pte Ltd.</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/104667">Cher Siang Koh</a>, <span class="data_meta">70</span> </span> <span class="data_lbl">Independent Non-Executive Director</span> </td> <td> <span class="data_lbl">Singapore Housing &amp; Development Board, United Overseas Bank Ltd., CapitaLand Ltd., United Overseas Bank Ltd. (Singapore), Thye Hua Kwan Moral Charities Ltd., Mechanobiology Institute, Singapore Golf Association, Singapore Cooperation Enterprise, CapitaLand Hope Foundation, Singapore Deposit Insurance Corp., Singapore Island Country Club</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/114522422">Yew Huat Ong</a>, <span class="data_meta">60</span> </span> <span class="data_lbl">Independent Non-Executive Director</span> </td> <td> <span class="data_lbl">United Overseas Bank Ltd. (Singapore)</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86318967">Jue Hiang Cheng</a>, <span class="data_meta">62</span> </span> <span class="data_lbl">Independent Non-Executive Director</span> </td> <td> <span class="data_lbl">SPH MediaBoxOffice Pte Ltd., SPH Interactive Pte Ltd., FEO Hospitality Trust Management Pte Ltd., Far East Hospitality Trust, FEO Hospitality Asset Management Pte Ltd., SPH Interactive International Pte Ltd., Singapore Institute of Directors, 701Search Pte Ltd., Ntuc Fairprice Foundation Ltd., Ashoka Innovators for the Public (Singapore) Ltd., United Overseas Bank Ltd. (Singapore), Council For Third Age Ltd., Integrated Information Systems, Inc., Aescapulus Holdings Pte Ltd., Singapore Health Services Pte Ltd., Integrated Health Information Systems Pte Ltd., SymAsia Foundation Ltd., Asia Philantrophic Ventures Pte Ltd., Asia Philanthropic Ventures Pte Ltd., Caritas Humanitarian Aid &amp; Relief Initiatives, Singapore</span> </td> </tr> <tr> <td> <span class="data_data"> <a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/41491049">Franklin Leo Lavin</a>, <span class="data_meta">58</span> </span> <span class="data_lbl">Independent Non-Executive Director</span> </td> <td> <span class="data_lbl">Far Eastern Bank Ltd., Globe Specialty Metals, Inc., CONSISTEL (Singapore) Pte Ltd., United Overseas Bank Ltd. (Singapore), United Overseas Bank Ltd., Export Now, Inc.</span> </td> </tr> </tbody> </table> </div> <div class="bottomStrap_more"> <a href="#" id class="moreLink loadMoreLink">expand</a> </div> </div> <div class="cr_data cr_all_executives"> <h4>All Executives</h4> <div class="scrollBox"> <ul class="cr_data_collection cr_all_executives"> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86291589">Ee Cheong Wee</a></span> <span class="data_lbl">Deputy Chairman &amp; Chief Executive Officer</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86291593">Wai Cheng Hwee</a></span> <span class="data_lbl">Head-Group Technology &amp; Operations</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86291587">Wai Fai Lee</a></span> <span class="data_lbl">Chief Financial Officer</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/4815192">Victor Ngo</a></span> <span class="data_lbl">Head-Group Compliance</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/122181365">See-Ming Ip Yeung</a></span> <span class="data_lbl">Managing Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/122099381">Chin Voon-Fat</a></span> <span class="data_lbl">Head-Group Wholesale Banking</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/120136914">Kok Seong Chan</a></span> <span class="data_lbl">Group Chief Risk Officer</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/115461061">Wah Yan Wong</a></span> <span class="data_lbl">Head-Group Strategy &amp; International Management</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/160726">Terence Ong</a></span> <span class="data_lbl">Head-Global Markets &amp; Investment Management</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86328526">Chin Yong Lee</a></span> <span class="data_lbl">Head-Group Retail</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/16055509">Michael Lien</a></span> <span class="data_lbl">Non-Executive Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/104206">Cho Yaw Wee</a></span> <span class="data_lbl">Chairman-Emeritus</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/152463410">Carrie Ann Mathews</a></span> <span class="data_lbl">Head-Group Strategic Communications</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/120300850">Shih Tung Lin</a></span> <span class="data_lbl">Investor Relations Contact</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/95901534">Mei Leng Wong</a></span> <span class="data_lbl">Head-Group Human Resources</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/138452461">Ming Kuang Sia</a></span> <span class="data_lbl">Co-Secretary</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/151489730">Kwee Soik Sim</a></span> <span class="data_lbl">Co-Secretary</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/16489539">Fu Hua Hsieh</a></span> <span class="data_lbl">Chairman</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86320739">Khirn Hai Yeo</a></span> <span class="data_lbl">Independent Non-Executive Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/154674047">Kan Seng Wong</a></span> <span class="data_lbl">Independent Non-Executive Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/13470908">Alexander Charles Hungate</a></span> <span class="data_lbl">Independent Non-Executive Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/98308786">Hwee Hua Lim</a></span> <span class="data_lbl">Independent Non-Executive Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/104667">Cher Siang Koh</a></span> <span class="data_lbl">Independent Non-Executive Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/114522422">Yew Huat Ong</a></span> <span class="data_lbl">Independent Non-Executive Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/86318967">Jue Hiang Cheng</a></span> <span class="data_lbl">Independent Non-Executive Director</span> </div> </li> <li> <div class="cr_data_field"> <span class="data_data"><a href="http://quotes.wsj.com/SG/XSES/U11/company-people/executive-profile/41491049">Franklin Leo Lavin</a></span> <span class="data_lbl">Independent Non-Executive Director</span> </div> </li> </ul> </div> <div class="bottomStrap_more"> <a href="#" id class="moreLink loadMoreLink">expand</a> </div> </div> </div> </div> <!--data-module-name="quotes.module.companypeople.Module"--> <div intent in-at8units-append="#at8uTarget" in-at12units-append="#at12uTarget" in-at16units-append="#at12uTarget"> <div data-module-id="12" data-module-name="quotes.module.ads.responsiveAd" data-module-zone="ads" class="zonedModule"> <div class="boxadWrapper module" id="main-quotes-ad"> <span class="adTitle">Advertisement</span> <div class="quotes-ad-wrap" id="AD_G" data-ad-options="{&quot;adId&quot;:&quot;AD_G&quot;,&quot;adUnitPath&quot;:&quot;/2/asia.wsj.com/quotes_front&quot;,&quot;adSize&quot;:[[300,250],[300,1050]],&quot;adSizeMap&quot;:null,&quot;autoRefresh&quot;:false,&quot;adTargeting&quot;:{&quot;metazone&quot;:&quot;&quot;,&quot;msrc&quot;:null,&quot;circ&quot;:&quot;nonsub&quot;,&quot;sym&quot;:&quot;U11&quot;,&quot;p39&quot;:null}}" data-tracking="asia.wsj.com/quotes_front" data-cb-ad-id="TopRectangle"> </div> </div> </div>

【问题讨论】：

对于字体大小，尝试将其设置为“字体大小：20px”，对于颜色，使用类似“颜色：红色”的语法。
在 html 或 angularjs 中？ <div style="margin: 10px;font-size:20px;"ng-bind-html="keyPeople"></div>?
是的，应该改变字体大小。
不幸的是它没有。这就是为什么我不明白为什么。从图片中可以看出，它包含标题和表格。两种字体大小都不会改变
像这样尝试!important：<div style="margin: 10px;font-size:20px !important;"ng-bind-html="keyPeople"></div>

标签： html angularjs ionic-framework

【解决方案1】：

看看我已经使用了你所有的 ionic html 代码并保留了 h3 标签。并且 ng 样式运行良好。

var app = angular.module('plunker', []);

app.controller('MainCtrl', function($scope, $http) {

  /*$http.get("http://manzurul.atwebpages.com")
  .success(function(response){ 
    console.log('workingsdfsdf');
    
  }).error(function(error){
 
    if(!error) {
        $scope.name = "No data found"
        $scope.companyDescriptionStyle = {"color": "red","font-size":"40px"}
    }
  });*/
  $scope.companyDescriptionStyle = {
    "color": "blue",
    "font-size": "40px"
  };
  $scope.name = 'World';
  //Company Info
  var companyInfo1 = null;
  var companyInfo2 = null;

  $scope.companyInfo = null;
  $scope.companyInfo += "";

  //Description
  var description1 = "";
  $scope.companyDescription = "<p></p>";


  //Key People
  var keyPeople1 = "";
  $scope.keyPeople = "";

  //Average Growth Rates
  var growth = "";
  var growth1 = "";
  $scope.averageGrowthRates = "";
  $scope.averageGrowthRates += "";

  //ownership
  var ownership = "";
  $scope.averageGrowthRates += "";
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.11/angular.min.js"></script>
<div ng-app="plunker">
  <div ng-controller="MainCtrl">
    <p ng-style="nameStyle">Hello {{name}}!</p>
    <ion-view view-title="Company">
      <ion-nav-buttons side="left">
      </ion-nav-buttons>
      <ion-content id="comp">
        <ion-scroll>
          <h3 ng-style="companyDescriptionStyle">Company Info</h3>
          <div style="margin: 10px;" ng-bind-html="companyInfo"></div>
          <h3 ng-style="companyDescriptionStyle">Description</h3>
          <div style="margin: 10px;font-size:20px;" ng-bind-html="companyDescription"></div>
          <div style="margin: 10px;color:#AAAFFF;font-size:40px;" ng-bind-html="keyPeople"></div>
          <div style="margin: 10px;" ng-bind-html="averageGrowthRates"></div>
          <div style="margin: 10px;" ng-bind-html="ownership"></div>
        </ion-scroll>
      </ion-content>
    </ion-view>
  </div>
</div>

【讨论】：

关键是style="margin: 10px;font-size:20px;" 不能放大字体。正如上面 cmets 指出的那样
这不适用于 style 属性。这需要绑定在 $scope.companyDescriptionStyle = {"color": "red", "font-size": "20px"};有关更多信息，请参阅我更新的上述 plunker。
此外，我需要澄清的是，如果任何 css 属性在 angular 类中没有定义，那么您可以在双引号中使用该属性。
奇怪了，字体大小不生效。请参考我上面的更新。是不是解决问题的方向不对？我很好奇为什么红框里的字，无法更改
@bkcollection 我已经看到了你的实现。答案是你不能通过内联样式来做到这一点，你已经以角度方式绑定了样式，然后它就会起作用。

【解决方案2】：

如何仅使用 CSS 解决您的问题

.cr_profile_people.module > .mod_headerBox > h3 {
    font-size: 10px!important;
}

.cr_profile_people.module .cr_dataTable.cr_board_table > tbody > tr > th {
    font-size: 40px!important;
}

【讨论】：

【解决方案3】：

你可以使用 ng-class 指令来应用你的类

在这里查看用法：ng-class 您可以在 css 文件中定义类

    . companyDescriptionStyle {"color":"blue"};

不，你可以在 ng-class 中使用这个类

    <div style="margin: 10px;font-size:20px;" ng-bind-html="companyDescription" ng-class="companyDescriptionStyle"></div>

【讨论】：

同样的问题，font-size:20px放大字体没有生效