下载文件前，先创建文件夹（修正部分安卓机不自动创建文件夹的问题）

src/utils/autoGCFileSystem.js

@@ -6,6 +6,7 @@ const singleFileMaxSize = 50 * 1024 * 1024;
 const maxSpaceSize = 200 * 1024 * 1024;
 const dir = wx.env.USER_DATA_PATH;
 const genFilePath = (ipfsCid, extension, fileName) => `${dir}/${ipfsCid}/${fileName}.${extension}`;
+const genFileFolder = ipfsCid => `${dir}/${ipfsCid}`;
 const fileManager = getFileSystemManager();
 const isAndroid = wx.getSystemInfoSync().platform === 'android';
 const iosSupportFilesType = ['doc', 'docx', 'xls', 'xlsx', 'ppt', 'pptx', 'pdf'];
@@ -65,6 +66,7 @@ export function previewFile(ipfsCid, fileName, extension, fileSize) {
     fail: () => {
       gcDirSpace();
       showLoading({ mask: true });
+      fileManager.mkdirSync(genFileFolder(ipfsCid));
       const task = downloadFile(ipfsCid, {
         filePath,
         success: (param) => {