在query列表时全部查询再把cursor传递出去
使用cursor.getxxx()就可以了

            Uri dirUri=UriUtil.pathToUri2(path);
            Uri childrenUri= DocumentsContract.buildChildDocumentsUriUsingTree(dirUri, DocumentsContract.getDocumentId(dirUri));
            String[] proj= new String[] {
                DocumentsContract.Document.COLUMN_DOCUMENT_ID,
                DocumentsContract.Document.COLUMN_DISPLAY_NAME,//文件名
                DocumentsContract.Document.COLUMN_MIME_TYPE,
                DocumentsContract.Document.COLUMN_LAST_MODIFIED,//最后修改时间
                DocumentsContract.Document.COLUMN_SIZE//文件大小
            };
            Cursor cursor= context.getContentResolver().query(childrenUri, proj, null, null, null);
            if (cursor == null){
                return null;
            }
            while (cursor.moveToNext()) {
                Uri uri = DocumentsContract.buildDocumentUriUsingTree(dirUri, cursor.getString(0));

                String name=cursor.getString(1);
                boolean isDir=cursor.getString(2).equals(DocumentsContract.Document.MIME_TYPE_DIR);
                boolean isHidden=name.startsWith(".");
            }
            cursor.close();