<p>FormDate 对象使用一些键值对来模拟一个完整的表单，然后使用ajax发送这个 FormData 对象，后端便可以拿到表单中上传的文件。</p>    <h2>前端处理</h2>    <h3>HTML代码</h3>    <pre>  <code class="language-javascript"><form>      <input type="file" id="uploadFile" name="file">  </form></code></pre>    <p>如果只想上传图片：</p>    <pre>  <code class="language-javascript"><input id="uploadFile" type="file" name="file" accept="image/png,image/gif"/></code></pre>    <p>可配置属性：</p>    <ul>     <li>accept：表示可以选择的文件MIME类型，多个MIME类型用英文逗号分开，常用的MIME类型见下表。</li>     <li>multiple：是否可以选择多个文件，多个文件时其value值为第一个文件的虚拟路径。</li>    </ul>    <h3>常用MIME类型</h3>    <table>     <thead>      <tr>       <th>后缀名</th>       <th>MIME名称</th>      </tr>     </thead>     <tbody>      <tr>       <td>*.3gpp</td>       <td>audio/3gpp, video/3gpp</td>      </tr>      <tr>       <td>*.ac3</td>       <td>audio/ac3</td>      </tr>      <tr>       <td>*.asf</td>       <td>allpication/vnd.ms-asf</td>      </tr>      <tr>       <td>*.au</td>       <td>audio/basic</td>      </tr>      <tr>       <td>*.css</td>       <td>text/css</td>      </tr>      <tr>       <td>*.csv</td>       <td>text/csv</td>      </tr>      <tr>       <td>*.doc</td>       <td>application/msword</td>      </tr>      <tr>       <td>*.dot</td>       <td>application/msword</td>      </tr>      <tr>       <td>*.dtd</td>       <td>application/xml-dtd</td>      </tr>      <tr>       <td>*.dwg</td>       <td>image/vnd.dwg</td>      </tr>      <tr>       <td>*.dxf</td>       <td>image/vnd.dxf</td>      </tr>      <tr>       <td>*.gif</td>       <td>image/gif</td>      </tr>      <tr>       <td>*.htm</td>       <td>text/html</td>      </tr>      <tr>       <td>*.html</td>       <td>text/html</td>      </tr>      <tr>       <td>*.jp2</td>       <td>image/jp2</td>      </tr>      <tr>       <td>*.jpe</td>       <td>image/jpeg</td>      </tr>      <tr>       <td>*.jpeg</td>       <td>image/jpeg</td>      </tr>      <tr>       <td>*.jpg</td>       <td>image/jpeg</td>      </tr>      <tr>       <td>*.js</td>       <td>text/javascript, application/javascript</td>      </tr>      <tr>       <td>*.json</td>       <td>application/json</td>      </tr>      <tr>       <td>*.mp2</td>       <td>audio/mpeg, video/mpeg</td>      </tr>      <tr>       <td>*.mp3</td>       <td>audio/mpeg</td>      </tr>      <tr>       <td>*.mp4</td>       <td>audio/mp4, video/mp4</td>      </tr>      <tr>       <td>*.mpeg</td>       <td>video/mpeg</td>      </tr>      <tr>       <td>*.mpg</td>       <td>video/mpeg</td>      </tr>      <tr>       <td>*.mpp</td>       <td>application/vnd.ms-project</td>      </tr>      <tr>       <td>*.ogg</td>       <td>application/ogg, audio/ogg</td>      </tr>      <tr>       <td>*.pdf</td>       <td>application/pdf</td>      </tr>      <tr>       <td>*.png</td>       <td>image/png</td>      </tr>      <tr>       <td>*.pot</td>       <td>application/vnd.ms-powerpoint</td>      </tr>      <tr>       <td>*.pps</td>       <td>application/vnd.ms-powerpoint</td>      </tr>      <tr>       <td>*.ppt</td>       <td>application/vnd.ms-powerpoint</td>      </tr>      <tr>       <td>*.rtf</td>       <td>application/rtf, text/rtf</td>      </tr>      <tr>       <td>*.svf</td>       <td>image/vnd.svf</td>      </tr>      <tr>       <td>*.tif</td>       <td>image/tiff</td>      </tr>      <tr>       <td>*.tiff</td>       <td>image/tiff</td>      </tr>      <tr>       <td>*.txt</td>       <td>text/plain</td>      </tr>      <tr>       <td>*.wdb</td>       <td>application/vnd.ms-works</td>      </tr>      <tr>       <td>*.wps</td>       <td>application/vnd.ms-works</td>      </tr>      <tr>       <td>*.xhtml</td>       <td>application/xhtml+xml</td>      </tr>      <tr>       <td>*.xlc</td>       <td>application/vnd.ms-excel</td>      </tr>      <tr>       <td>*.xlm</td>       <td>application/vnd.ms-excel</td>      </tr>      <tr>       <td>*.xls</td>       <td>application/vnd.ms-excel</td>      </tr>      <tr>       <td>*.xlt</td>       <td>application/vnd.ms-excel</td>      </tr>      <tr>       <td>*.xlw</td>       <td>application/vnd.ms-excel</td>      </tr>      <tr>       <td>*.xml</td>       <td>text/xml, application/xml</td>      </tr>      <tr>       <td>*.zip</td>       <td>aplication/zip</td>      </tr>      <tr>       <td>*.xlsx</td>       <td>application/vnd.openxmlformats-officedocument.spreadsheetml.sheet</td>      </tr>     </tbody>    </table>    <h3>javascript代码</h3>    <pre>  <code class="language-javascript">$('#uploadFile').on('change',function(e){      var file = this.files[0];        var formData = new FormData();      formData.append('file',file);        $.ajax({          url: '/webgl/upload/zip',          type: 'post',          data: formData,          cache: false,          contentType: false,          processData: false,          success: function(res){             //          }      })  })</code></pre>    <p>这里我是在文件被选择上传后就会立即触发 ajax 上传文件事件，而表单中其他字段我没有使用 FormData 对象，所以 <form> 标签没有添加 enctype="multipart/form-data" 属性。</p>    <p>注：</p>    <ul>     <li>processData 设置为 false 。因为 data 值是 FormData 对象，不需要对数据做处理。</li>     <li>cache 设置为 false ，上传文件不需要缓存。</li>     <li>contentType 设置为 false 。</li>    </ul>    <h2>nodejs代码</h2>    <h3>multer模块</h3>    <p>我使用了 multer 模块，初始化 multer 模块配置</p>    <pre>  <code class="language-javascript">var storageZip = multer.diskStorage({      destination: function(req, file, cb) {        cb(null, 'public/uploads/zip')        //文件存储路径      },      filename: function(req, file, cb) {        cb(null, file.fieldname + '-' + Date.now() + '.zip')    //对文件重新命名，防止文件名冲突      }    })      var uploadZip = multer({      storage: storageZip    });</code></pre>    <h3>路由配置</h3>    <pre>  <code class="language-javascript">app.post('/webgl/upload/zip', uploadZip.single('file'), function(req, res) {      res.json(req.file)    })</code></pre>    <ul>     <li>这里 single() 参数名就是使用 FormData.append() 方法添加时的文件名，这里我用的是 file 。</li>     <li>上传结束之后，会把 file 对象返回给前端， file 对象会包含文件名等信息。</li>    </ul>    <p> </p>    <p>来自：https://juejin.im/post/58c64f2b0ce463005479f4d3</p>    <p> </p>