# uniapp 同步上傳圖片 \## [Promise 封裝](https://uniapp.dcloud.io/api/README?id=promise-%e5%b0%81%e8%a3%85) uni-app 對部分 API 進行了 Promise 封裝，返回數據的第一個參數是錯誤對象，第二個參數是返回數據。 詳細策略如下： - 異步的方法，如果不傳入 success、fail、complete 等 callback 參數，將以 Promise 返回數據。例如：uni.getImageInfo() - 異步的方法且有返回對象，如果希望獲取返回對象，必須至少傳入一項 success、fail、complete 等 callback 參數。例如：uni.connectSocket() - 同步的方法（即以 sync 結束），不封裝 Promise。例如：uni.getSystemInfoSync() - 以 create 開頭的方法，不封裝 Promise。例如：uni.createMapContext() - 以 manager 結束的方法，不封裝 Promise。例如：uni.getBackgroundAudioManager() 使用示例： ``` <pre class="calibre14">``` <span class="token6">// 默認方式</span> uni<span class="token1">.</span><span class="token3">request</span><span class="token1">(</span><span class="token1">{</span> url<span class="token1">:</span> <span class="token4">'https://www.example.com/request'</span><span class="token1">,</span> success<span class="token1">:</span> <span class="token1">(</span>res<span class="token1">)</span> <span class="token">=></span> <span class="token1">{</span> console<span class="token1">.</span><span class="token3">log</span><span class="token1">(</span>res<span class="token1">.</span>data<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="token6">// Promise</span> uni<span class="token1">.</span><span class="token3">request</span><span class="token1">(</span><span class="token1">{</span> url<span class="token1">:</span> <span class="token4">'https://www.example.com/request'</span> <span class="token1">}</span><span class="token1">)</span> <span class="token1">.</span><span class="token3">then</span><span class="token1">(</span>data <span class="token">=></span> <span class="token1">{</span><span class="token6">//data為一個數組，數組第一項為錯誤信息，第二項為返回數據</span> <span class="token2">var</span> <span class="token1">[</span>error<span class="token1">,</span> res<span class="token1">]</span> <span class="token">=</span> data<span class="token1">;</span> console<span class="token1">.</span><span class="token3">log</span><span class="token1">(</span>res<span class="token1">.</span>data<span class="token1">)</span><span class="token1">;</span> <span class="token1">}</span><span class="token1">)</span> <span class="token6">// Await</span> <span class="token2">function</span> <span class="token2">async</span> <span class="token3">request</span> <span class="token1">(</span><span class="token1">)</span> <span class="token1">{</span> <span class="token2">var</span> <span class="token1">[</span>error<span class="token1">,</span> res<span class="token1">]</span> <span class="token">=</span> <span class="token2">await</span> uni<span class="token1">.</span><span class="token3">request</span><span class="token1">(</span><span class="token1">{</span> url<span class="token1">:</span> <span class="token4">'https://www.example.com/request'</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>res<span class="token1">.</span>data<span class="token1">)</span><span class="token1">;</span> <span class="token1">}</span> ``` ```