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  18. <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="前端" class="dropdown-title"><a href="/blog/web/" class="link-title">前端</a> <span class="title" style="display:none;">前端</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><h4>前端文章</h4> <ul class="dropdown-subitem-wrapper"><li class="dropdown-subitem"><a href="/blog/pages/8143cc480faf9a11/" class="nav-link">JavaScript</a></li></ul></li><li class="dropdown-item"><h4>学习笔记</h4> <ul class="dropdown-subitem-wrapper"><li class="dropdown-subitem"><a href="/blog/note/javascript/" class="nav-link">《JavaScript教程》</a></li><li class="dropdown-subitem"><a href="/blog/note/js/" class="nav-link">《JavaScript高级程序设计》</a></li><li class="dropdown-subitem"><a href="/blog/note/es6/" class="nav-link">《ES6 教程》</a></li><li class="dropdown-subitem"><a href="/blog/note/vue/" class="nav-link">《Vue》</a></li><li class="dropdown-subitem"><a href="/blog/note/react/" class="nav-link">《React》</a></li><li class="dropdown-subitem"><a href="/blog/note/typescript-axios/" class="nav-link">《TypeScript 从零实现 axios》</a></li><li class="dropdown-subitem"><a href="/blog/note/git/" class="nav-link">《Git》</a></li><li class="dropdown-subitem"><a href="/blog/pages/51afd6/" class="nav-link">TypeScript</a></li><li class="dropdown-subitem"><a href="/blog/pages/4643cd/" class="nav-link">JS设计模式总结</a></li></ul></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="页面" class="dropdown-title"><a href="/blog/ui/" class="link-title">页面</a> <span class="title" style="display:none;">页面</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/blog/pages/8309a5b876fc95e3/" class="nav-link">HTML</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/0a83b083bdf257cb/" class="nav-link">CSS</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="技术" class="dropdown-title"><a href="/blog/technology/" class="link-title">技术</a> <span class="title" style="display:none;">技术</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/blog/pages/9a7ee40fc232253e/" class="nav-link">技术文档</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/4c778760be26d8b3/" class="nav-link">GitHub技巧</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/117708e0af7f0bd9/" class="nav-link">Nodejs</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/41f87d890d0a02af/" class="nav-link">博客搭建</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="更多" class="dropdown-title"><a href="/blog/more/" class="link-title">更多</a> <span class="title" style="display:none;">更多</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/blog/pages/f2a556/" class="nav-link">学习</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/aea6571b7a8bae86/" class="nav-link">面试</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/2d615df9a36a98ed/" class="nav-link">心情杂货</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/baaa02/" class="nav-link">实用技巧</a></li><li class="dropdown-item"><!----> <a href="/blog/friends/" class="nav-link">友情链接</a></li></ul></div></div><div class="nav-item"><a href="/blog/about/" class="nav-link">关于</a></div><div class="nav-item"><a href="/blog/pages/beb6c0bd8a66cea6/" class="nav-link">收藏</a></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="索引" class="dropdown-title"><a href="/blog/archives/" class="link-title">索引</a> <span class="title" style="display:none;">索引</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/blog/categories/" class="nav-link">分类</a></li><li class="dropdown-item"><!----> <a href="/blog/tags/" class="nav-link">标签</a></li><li class="dropdown-item"><!----> <a href="/blog/archives/" class="nav-link">归档</a></li></ul></div></div> <a href="https://github.com/heBody/blog" target="_blank" rel="noopener noreferrer" class="repo-link">
  19. GitHub
  20. <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></nav></div></header> <div class="sidebar-mask"></div> <div class="sidebar-hover-trigger"></div> <aside class="sidebar" style="display:none;"><div class="blogger"><img src="https://fastly.jsdelivr.net/gh/xugaoyi/image_store/blog/20200103123203.jpg"> <div class="blogger-info"><h3>彪哥</h3> <span>爱好前端</span></div></div> <nav class="nav-links"><div class="nav-item"><a href="/blog/" class="nav-link">首页</a></div><div class="nav-item"><a href="http://fseller.com" target="_blank" rel="noopener noreferrer" class="nav-link external">
  21. 个人游戏网站
  22. <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="前端" class="dropdown-title"><a href="/blog/web/" class="link-title">前端</a> <span class="title" style="display:none;">前端</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><h4>前端文章</h4> <ul class="dropdown-subitem-wrapper"><li class="dropdown-subitem"><a href="/blog/pages/8143cc480faf9a11/" class="nav-link">JavaScript</a></li></ul></li><li class="dropdown-item"><h4>学习笔记</h4> <ul class="dropdown-subitem-wrapper"><li class="dropdown-subitem"><a href="/blog/note/javascript/" class="nav-link">《JavaScript教程》</a></li><li class="dropdown-subitem"><a href="/blog/note/js/" class="nav-link">《JavaScript高级程序设计》</a></li><li class="dropdown-subitem"><a href="/blog/note/es6/" class="nav-link">《ES6 教程》</a></li><li class="dropdown-subitem"><a href="/blog/note/vue/" class="nav-link">《Vue》</a></li><li class="dropdown-subitem"><a href="/blog/note/react/" class="nav-link">《React》</a></li><li class="dropdown-subitem"><a href="/blog/note/typescript-axios/" class="nav-link">《TypeScript 从零实现 axios》</a></li><li class="dropdown-subitem"><a href="/blog/note/git/" class="nav-link">《Git》</a></li><li class="dropdown-subitem"><a href="/blog/pages/51afd6/" class="nav-link">TypeScript</a></li><li class="dropdown-subitem"><a href="/blog/pages/4643cd/" class="nav-link">JS设计模式总结</a></li></ul></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="页面" class="dropdown-title"><a href="/blog/ui/" class="link-title">页面</a> <span class="title" style="display:none;">页面</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/blog/pages/8309a5b876fc95e3/" class="nav-link">HTML</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/0a83b083bdf257cb/" class="nav-link">CSS</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="技术" class="dropdown-title"><a href="/blog/technology/" class="link-title">技术</a> <span class="title" style="display:none;">技术</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/blog/pages/9a7ee40fc232253e/" class="nav-link">技术文档</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/4c778760be26d8b3/" class="nav-link">GitHub技巧</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/117708e0af7f0bd9/" class="nav-link">Nodejs</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/41f87d890d0a02af/" class="nav-link">博客搭建</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="更多" class="dropdown-title"><a href="/blog/more/" class="link-title">更多</a> <span class="title" style="display:none;">更多</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/blog/pages/f2a556/" class="nav-link">学习</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/aea6571b7a8bae86/" class="nav-link">面试</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/2d615df9a36a98ed/" class="nav-link">心情杂货</a></li><li class="dropdown-item"><!----> <a href="/blog/pages/baaa02/" class="nav-link">实用技巧</a></li><li class="dropdown-item"><!----> <a href="/blog/friends/" class="nav-link">友情链接</a></li></ul></div></div><div class="nav-item"><a href="/blog/about/" class="nav-link">关于</a></div><div class="nav-item"><a href="/blog/pages/beb6c0bd8a66cea6/" class="nav-link">收藏</a></div><div class="nav-item"><div class="dropdown-wrapper"><button type="button" aria-label="索引" class="dropdown-title"><a href="/blog/archives/" class="link-title">索引</a> <span class="title" style="display:none;">索引</span> <span class="arrow right"></span></button> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/blog/categories/" class="nav-link">分类</a></li><li class="dropdown-item"><!----> <a href="/blog/tags/" class="nav-link">标签</a></li><li class="dropdown-item"><!----> <a href="/blog/archives/" class="nav-link">归档</a></li></ul></div></div> <a href="https://github.com/heBody/blog" target="_blank" rel="noopener noreferrer" class="repo-link">
  23. GitHub
  24. <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></nav> <ul class="sidebar-links"><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading open"><span>基础</span> <span class="arrow down"></span></p> <ul class="sidebar-links sidebar-group-items"><li><a href="/blog/pages/114158caa9e96df0/" class="sidebar-link">MVVM模式</a></li><li><a href="/blog/pages/176808a1b5f843b8/" class="sidebar-link">生命周期</a></li><li><a href="/blog/pages/351f72ecd9c41129/" class="sidebar-link">计算属性 vs 方法 vs 侦听属性</a></li><li><a href="/blog/pages/73e4064340277b05/" class="sidebar-link">v-if vs v-show</a></li><li><a href="/blog/pages/04783a6691cc9d06/" aria-current="page" class="active sidebar-link">列表渲染之数组、对象更新检测</a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header level2"><a href="/blog/pages/04783a6691cc9d06/#数组更新检测" class="sidebar-link">数组更新检测</a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header level4"><a href="/blog/pages/04783a6691cc9d06/#变异方法-mutation-method" class="sidebar-link">变异方法 (mutation method)</a></li><li class="sidebar-sub-header level4"><a href="/blog/pages/04783a6691cc9d06/#替换数组" class="sidebar-link">替换数组</a></li><li class="sidebar-sub-header level4"><a href="/blog/pages/04783a6691cc9d06/#注意事项" class="sidebar-link">注意事项</a></li></ul></li><li class="sidebar-sub-header level2"><a href="/blog/pages/04783a6691cc9d06/#对象变更检测注意事项" class="sidebar-link">对象变更检测注意事项</a></li><li class="sidebar-sub-header level2"><a href="/blog/pages/04783a6691cc9d06/#总结" class="sidebar-link">总结</a></li></ul></li></ul></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>组件</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>过渡&amp;动画</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>可复用性&amp;组合</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>工具</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>规模化</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>Vuex</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>其他</span> <span class="arrow right"></span></p> <!----></section></li></ul> </aside> <div><main class="page"><div class="theme-vdoing-wrapper "><div class="articleInfo-wrap" data-v-06970110><div class="articleInfo" data-v-06970110><ul class="breadcrumbs" data-v-06970110><li data-v-06970110><a href="/blog/" title="首页" class="iconfont icon-home router-link-active" data-v-06970110></a></li> <li data-v-06970110><a href="/blog/note/vue/#《Vue》笔记" data-v-06970110>《Vue》笔记</a></li><li data-v-06970110><a href="/blog/note/vue/#基础" data-v-06970110>基础</a></li></ul> <div class="info" data-v-06970110><div title="作者" class="author iconfont icon-touxiang" data-v-06970110><a href="https://github.com/heBody" target="_blank" title="作者" class="beLink" data-v-06970110>heBody</a></div> <div title="创建时间" class="date iconfont icon-riqi" data-v-06970110><a href="javascript:;" data-v-06970110>2020-02-05</a></div> <!----></div></div></div> <!----> <div class="content-wrapper"><div class="right-menu-wrapper"><div class="right-menu-margin"><div class="right-menu-title">目录</div> <div class="right-menu-content"></div></div></div> <h1><img src="data:image/png;base64,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">列表渲染之数组、对象更新检测<!----></h1> <div class="theme-vdoing-content content__default"><h1 id="列表渲染之数组、对象更新检测"><a href="#列表渲染之数组、对象更新检测" class="header-anchor">#</a> 列表渲染之数组、对象更新检测</h1> <p><a href="https://cn.vuejs.org/v2/guide/list.html#%E6%95%B0%E7%BB%84%E6%9B%B4%E6%96%B0%E6%A3%80%E6%B5%8B" target="_blank" rel="noopener noreferrer">数组更新检测API<span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a> <a href="https://cn.vuejs.org/v2/guide/list.html#%E5%AF%B9%E8%B1%A1%E5%8F%98%E6%9B%B4%E6%A3%80%E6%B5%8B%E6%B3%A8%E6%84%8F%E4%BA%8B%E9%A1%B9" target="_blank" rel="noopener noreferrer">对象更新检测API<span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></p> <h2 id="数组更新检测"><a href="#数组更新检测" class="header-anchor">#</a> 数组更新检测</h2> <h4 id="变异方法-mutation-method"><a href="#变异方法-mutation-method" class="header-anchor">#</a> 变异方法 (mutation method)</h4> <p>Vue 将被侦听的数组的变异方法进行了包裹,所以它们也将会触发视图更新。这些被包裹过的方法包括:
  25. </p> <ul><li><code>push()</code>末尾添加</li> <li><code>pop()</code>末尾删除</li> <li><code>shift()</code> 首位删除</li> <li><code>unshift()</code> 首位添加</li> <li><code>splice()</code> 拼合</li> <li><code>sort()</code> 排序</li> <li><code>reverse()</code> 反转</li></ul> <p><a href="https://heBody.com/pages/74d2ab3fbfeaaa68/#_3%E3%80%81%E5%AE%9E%E4%BE%8B%E6%96%B9%E6%B3%95" target="_blank" rel="noopener noreferrer">数组实例方法<span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></p> <h4 id="替换数组"><a href="#替换数组" class="header-anchor">#</a> 替换数组</h4> <p>变异方法,顾名思义,会改变调用了这些方法的原始数组。相比之下,也有非变异 (non-mutating method) 方法,例如 <code>filter()</code>、<code>concat()</code> 和 <code>slice()</code> 。它们不会改变原始数组,而<strong>总是返回一个新数组</strong>。当使用非变异方法时,可以用新数组替换旧数组:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code>example1<span class="token punctuation">.</span>items <span class="token operator">=</span> example1<span class="token punctuation">.</span>items<span class="token punctuation">.</span><span class="token function">filter</span><span class="token punctuation">(</span><span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token parameter">item</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
  26. <span class="token keyword">return</span> item<span class="token punctuation">.</span>message<span class="token punctuation">.</span><span class="token function">match</span><span class="token punctuation">(</span><span class="token regex"><span class="token regex-delimiter">/</span><span class="token regex-source language-regex">Foo</span><span class="token regex-delimiter">/</span></span><span class="token punctuation">)</span>
  27. <span class="token punctuation">}</span><span class="token punctuation">)</span>
  28. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br></div></div><p>你可能认为这将导致 Vue 丢弃现有 DOM 并重新渲染整个列表。幸运的是,事实并非如此。Vue 为了使得 DOM 元素得到最大范围的重用而实现了一些智能的启发式方法,所以用一个含有相同元素的数组去替换原来的数组是非常高效的操作。</p> <h4 id="注意事项"><a href="#注意事项" class="header-anchor">#</a> 注意事项</h4> <p><strong>由于 JavaScript 的限制,Vue 不能检测以下数组的变动</strong></p> <ol><li>当你利用索引直接设置一个数组项时,例如:<code>vm.items[indexOfItem] = newValue</code></li> <li>当你修改数组的长度时,例如:<code>vm.items.length = newLength</code></li></ol> <p>为了解决第一类问题,以下两种方式都可以实现和 <code>vm.items[indexOfItem] = newValue</code> 相同的效果,同时也将在响应式系统内触发状态更新:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code><span class="token comment">// Vue.set</span>
  29. Vue<span class="token punctuation">.</span><span class="token function">set</span><span class="token punctuation">(</span>vm<span class="token punctuation">.</span>items<span class="token punctuation">,</span> indexOfItem<span class="token punctuation">,</span> newValue<span class="token punctuation">)</span>
  30. <span class="token comment">// Array.prototype.splice</span>
  31. vm<span class="token punctuation">.</span>items<span class="token punctuation">.</span><span class="token function">splice</span><span class="token punctuation">(</span>indexOfItem<span class="token punctuation">,</span> <span class="token number">1</span><span class="token punctuation">,</span> newValue<span class="token punctuation">)</span>
  32. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br></div></div><p>你也可以使用 <a href="https://cn.vuejs.org/v2/api/#vm-set" target="_blank" rel="noopener noreferrer"><code>vm.$set</code><span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a> 实例方法,该方法是全局方法 <code>Vue.set</code> 的一个别名:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code>vm<span class="token punctuation">.</span><span class="token function">$set</span><span class="token punctuation">(</span>vm<span class="token punctuation">.</span>items<span class="token punctuation">,</span> indexOfItem<span class="token punctuation">,</span> newValue<span class="token punctuation">)</span>
  33. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>为了解决第二类问题,你可以使用 <code>splice</code>:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code>vm<span class="token punctuation">.</span>items<span class="token punctuation">.</span><span class="token function">splice</span><span class="token punctuation">(</span>newLength<span class="token punctuation">)</span>
  34. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><h2 id="对象变更检测注意事项"><a href="#对象变更检测注意事项" class="header-anchor">#</a> 对象变更检测注意事项</h2> <blockquote><p>列表循环对象示例</p> <div class="language-html line-numbers-mode"><pre class="language-html"><code><span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>div</span> <span class="token attr-name">v-for</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">&quot;</span>(item, key, index) in obj<span class="token punctuation">&quot;</span></span><span class="token punctuation">&gt;</span></span>
  35. <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>div</span><span class="token punctuation">&gt;</span></span>
  36. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div></blockquote> <p>还是由于 JavaScript 的限制,<strong>Vue 不能检测对象属性的添加或删除</strong>:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code><span class="token keyword">var</span> vm <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span>
  37. <span class="token literal-property property">data</span><span class="token operator">:</span> <span class="token punctuation">{</span>
  38. <span class="token literal-property property">a</span><span class="token operator">:</span> <span class="token number">1</span>
  39. <span class="token punctuation">}</span>
  40. <span class="token punctuation">}</span><span class="token punctuation">)</span>
  41. <span class="token comment">// `vm.a` 现在是响应式的</span>
  42. vm<span class="token punctuation">.</span>b <span class="token operator">=</span> <span class="token number">2</span>
  43. <span class="token comment">// `vm.b` 不是响应式的</span>
  44. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><p>对于已经创建的实例,Vue 不允许动态添加根级别的响应式属性。</p> <p>但是,可以使用 <code>Vue.set(object, propertyName, value)</code> 方法向嵌套对象添加响应式属性。例如,对于:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code><span class="token keyword">var</span> vm <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span>
  45. <span class="token literal-property property">data</span><span class="token operator">:</span> <span class="token punctuation">{</span>
  46. <span class="token literal-property property">userProfile</span><span class="token operator">:</span> <span class="token punctuation">{</span>
  47. <span class="token literal-property property">name</span><span class="token operator">:</span> <span class="token string">'Anika'</span>
  48. <span class="token punctuation">}</span>
  49. <span class="token punctuation">}</span>
  50. <span class="token punctuation">}</span><span class="token punctuation">)</span>
  51. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p>你可以添加一个新的 <code>age</code> 属性到嵌套的 <code>userProfile</code> 对象:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code>Vue<span class="token punctuation">.</span><span class="token function">set</span><span class="token punctuation">(</span>vm<span class="token punctuation">.</span>userProfile<span class="token punctuation">,</span> <span class="token string">'age'</span><span class="token punctuation">,</span> <span class="token number">27</span><span class="token punctuation">)</span>
  52. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>你还可以使用 <code>vm.$set</code> 实例方法,它只是全局 <code>Vue.set</code> 的别名:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code>vm<span class="token punctuation">.</span><span class="token function">$set</span><span class="token punctuation">(</span>vm<span class="token punctuation">.</span>userProfile<span class="token punctuation">,</span> <span class="token string">'age'</span><span class="token punctuation">,</span> <span class="token number">27</span><span class="token punctuation">)</span>
  53. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>有时你可能需要为已有对象赋值多个新属性,比如使用 <code>Object.assign()</code> 或 <code>_.extend()</code>。在这种情况下,你应该用两个对象的属性创建一个新的对象。所以,如果你想添加新的响应式属性,不要像这样:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code>Object<span class="token punctuation">.</span><span class="token function">assign</span><span class="token punctuation">(</span>vm<span class="token punctuation">.</span>userProfile<span class="token punctuation">,</span> <span class="token punctuation">{</span>
  54. <span class="token literal-property property">age</span><span class="token operator">:</span> <span class="token number">27</span><span class="token punctuation">,</span>
  55. <span class="token literal-property property">favoriteColor</span><span class="token operator">:</span> <span class="token string">'Vue Green'</span>
  56. <span class="token punctuation">}</span><span class="token punctuation">)</span>
  57. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br></div></div><p>你应该这样做:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code>vm<span class="token punctuation">.</span>userProfile <span class="token operator">=</span> Object<span class="token punctuation">.</span><span class="token function">assign</span><span class="token punctuation">(</span><span class="token punctuation">{</span><span class="token punctuation">}</span><span class="token punctuation">,</span> vm<span class="token punctuation">.</span>userProfile<span class="token punctuation">,</span> <span class="token punctuation">{</span>
  58. <span class="token literal-property property">age</span><span class="token operator">:</span> <span class="token number">27</span><span class="token punctuation">,</span>
  59. <span class="token literal-property property">favoriteColor</span><span class="token operator">:</span> <span class="token string">'Vue Green'</span>
  60. <span class="token punctuation">}</span><span class="token punctuation">)</span>
  61. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br></div></div><h2 id="总结"><a href="#总结" class="header-anchor">#</a> 总结</h2> <p>一、使数组更新具有响应式可使用的办法:</p> <ol><li>使用变异方法 (push、pop、unshift、shift、splice、sort、reverse)</li> <li>替换数组引用 (对不改变原数组的方法可使用替换数组)</li> <li>使用Vue.set()方法</li></ol> <p>二、使对象属性的添加或删除具有响应式可使用的办法:</p> <ol><li>替换对象引用</li> <li>使用Vue.set()方法</li></ol> <p>三、Vue.set() 语法:</p> <div class="language-js line-numbers-mode"><pre class="language-js"><code><span class="token comment">// 向数组更新数据</span>
  62. Vue<span class="token punctuation">.</span><span class="token function">set</span><span class="token punctuation">(</span>vm<span class="token punctuation">.</span>items<span class="token punctuation">,</span> indexOfItem<span class="token punctuation">,</span> newValue<span class="token punctuation">)</span>
  63. 即 Vue<span class="token punctuation">.</span><span class="token function">set</span><span class="token punctuation">(</span>原数组<span class="token punctuation">,</span> 索引<span class="token punctuation">,</span> 新数据<span class="token punctuation">)</span>
  64. <span class="token comment">// 向对象更新数据</span>
  65. Vue<span class="token punctuation">.</span><span class="token function">set</span><span class="token punctuation">(</span>object<span class="token punctuation">,</span> propertyName<span class="token punctuation">,</span> value<span class="token punctuation">)</span>
  66. 即 Vue<span class="token punctuation">.</span><span class="token function">set</span><span class="token punctuation">(</span>原对象<span class="token punctuation">,</span> 属性名<span class="token punctuation">,</span> 值<span class="token punctuation">)</span>
  67. </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><blockquote><p>vm.$set() 实例方法是 Vue.set() 全局方法的别名</p></blockquote></div></div> <div class="page-edit"><div class="edit-link"><a href="https://github.com/heBody/blog/edit/master/docs/《Vue》笔记/01.基础/35.列表渲染之数组、对象更新检测.md" target="_blank" rel="noopener noreferrer">编辑</a> <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></div> <div class="tags"><a href="/blog/tags/?tag=Vue" title="标签">#Vue</a></div> <div class="last-updated"><span class="prefix">上次更新:</span> <span class="time">2022/12/14, 19:36:42</span></div></div> <div class="page-nav-wapper"><div class="page-nav-centre-wrap"><a href="/blog/pages/73e4064340277b05/" class="page-nav-centre page-nav-centre-prev"><div class="tooltip">v-if vs v-show</div></a> <a href="/blog/pages/83a1ab785e7fd70c/" class="page-nav-centre page-nav-centre-next"><div class="tooltip">使用组件的细节点</div></a></div> <div class="page-nav"><p class="inner"><span class="prev">
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