我用下面的code为设置缩略图文件上传在谷歌驱动器：

I use the following code to set thumb nail for file to upload on Google Drive :

// Set thumb nail path                  
String thumbnail_path = mediaContent.getFile().getAbsolutePath();   
// thumbnail_path : "/sdcard/Picture/ds01.jpg" 

// File's meta data.                    
File body = new File();                 
body.setTitle(fileContent.getName());                   
body.setMimeType("image/jpeg");

// Thumb nail                   
final Thumbnail thumbnail = new Thumbnail();                    
thumbnail.setMimeType("image/jpeg");            

// UPDATE HERE : define byte array
byte[] data = Base64.decodeBase64(getData(thumbnail_path));  
thumbnail.encodeImage(Base64.encodeBase64String(data));

// set thumb nail for file
body.setThumbnail(thumbnail);

在code运行成功，但我认为有些事情错了，我不知道在哪里。 因为我用下面的code去文件的相关信息，并在 file.getThumbnail（）为null 。 （的getTitle（）和getMimeType（）是成功的的）。

The code run successful, but I think something wrong, i don't know where. Because I used following code to get information related to file, and the file.getThumbnail() is null. (getTitle() and getMimeType() is successful).

private static void printFile(Drive service, String fileId) {
        try {
            File file = service.files().get(fileId).execute();

            System.out.println("Title: " + file.getTitle());
            System.out.println("MIME type: " + file.getMimeType());
            System.out.println("getThumbnail: " + file.getThumbnail());
        } catch (IOException e) {
            System.out.println("An error occured: " + e);
        }
    }

下面code是上传，它成功的：

The following code is for uploading, it successful :

String folderId = ManageFile.getIdLink();
Log.d(TAG, "folderId " + folderId);
body.setParents(Arrays.asList(new ParentReference().setId(folderId)));

File file = service.files().insert(body, mediaContent).execute();

更新： - 我想补充的code代表介绍了如何获得字节数组

UPDATE : - I add those code for describe how to get byte array.

protected byte[] getData(String thumbnail_path) {
        byte[] imageData = null;
        final int THUMBNAIL_SIZE = 96;

        FileInputStream fis;
        try {
            fis = new FileInputStream(thumbnail_path);

            Bitmap imageBitmap = BitmapFactory.decodeStream(fis);
            imageBitmap = Bitmap.createScaledBitmap(imageBitmap, THUMBNAIL_SIZE, THUMBNAIL_SIZE, false);

            ByteArrayOutputStream baos = new ByteArrayOutputStream();  
            imageBitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);

            // byte data array
            imageData = baos.toByteArray();

            return imageData;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }

P / S： - 获取文件 - 文件资源

p/s : - Get file - File resource

请告诉我如何获取拇指指甲形象成功。 谢谢！

Please tell me how to get Thumb nail image successful. Thanks!

推荐答案

您c从的getData 方法是不连接codeD中的数据去$ C $ 。

byte[] data = Base64.decodeBase64(getData(thumbnail_path));  
thumbnail.setImage(Base64.encodeBase64String(data));

byte[] data = getData(thumbnail_path);  
thumbnail.encodeImage(data);