# uniapp引入全局變量 ## 掛載 Vue.prototype 將一些使用頻率較高的常量或者方法，直接擴展到 Vue.prototype 上，每個 Vue 對象都會“繼承”下來。 ### 注意這種方式只支持vue頁面 示例如下： 在 main.js 中掛載屬性/方法 ``` <pre class="calibre13">``` 復制代碼Vue<span class="token1">.</span>prototype<span class="token1">.</span>websiteUrl <span class="token">=</span> <span class="token4">'http://uniapp.dcloud.io'</span><span class="token1">;</span> Vue<span class="token1">.</span>prototype<span class="token1">.</span>now <span class="token">=</span> Date<span class="token1">.</span>now <span class="token">||</span> <span class="token2">function</span> <span class="token1">(</span><span class="token1">)</span> <span class="token1">{</span> <span class="token2">return</span> <span class="token2">new</span> <span class="token3">Date</span><span class="token1">(</span><span class="token1">)</span><span class="token1">.</span><span class="token3">getTime</span><span class="token1">(</span><span class="token1">)</span><span class="token1">;</span> <span class="token1">}</span><span class="token1">;</span> Vue<span class="token1">.</span>prototype<span class="token1">.</span>isArray <span class="token">=</span> Array<span class="token1">.</span>isArray <span class="token">||</span> <span class="token2">function</span> <span class="token1">(</span>obj<span class="token1">)</span> <span class="token1">{</span> <span class="token2">return</span> obj <span class="token2">instanceof</span> <span class="token3">Array</span><span class="token1">;</span> <span class="token1">}</span><span class="token1">;</span> ``` ``` 然后在 pages/index/index.vue 中調用 ``` <pre class="calibre13">``` 復制代碼<span class="token"><</span>script<span class="token">></span> <span class="token2">export</span> <span class="token2">default</span> <span class="token1">{</span> <span class="token3">data</span><span class="token1">(</span><span class="token1">)</span> <span class="token1">{</span> <span class="token2">return</span> <span class="token1">{</span><span class="token1">}</span><span class="token1">;</span> <span class="token1">}</span><span class="token1">,</span> <span class="token3">onLoad</span><span class="token1">(</span><span class="token1">)</span><span class="token1">{</span> console<span class="token1">.</span><span class="token3">log</span><span class="token1">(</span><span class="token4">'now:'</span> <span class="token">+</span> <span class="token2">this</span><span class="token1">.</span><span class="token3">now</span><span class="token1">(</span><span class="token1">)</span><span class="token1">)</span><span class="token1">;</span> <span class="token1">}</span><span class="token1">,</span> <span class="token">**</span># <span class="token6">/**注意用的時候要加this**/</span><span class="token">**</span> methods<span class="token1">:</span> <span class="token1">{</span> <span class="token1">}</span> <span class="token1">}</span> <span class="token"><</span><span class="token">/</span>script<span class="token">></span> ``` ``` 這種方式，只需要在 main.js 中定義好即可在每個頁面中直接調用。 **Tips** - 每個頁面中不要在出現重復的屬性或方法名。 - 建議在 Vue.prototype 上掛載的屬性或方法，可以加一個統一的前綴。比如 $url、global\_url 這樣，在閱讀代碼時也容易與當前頁面的內容區分開。