我尝试过很多例子，并没有找到任何好的解决方案。
我想将我的应用程序的数据存储在sqlite数据库中，然后将其与安装该应用程序的用户的google驱动器帐户同步。
还有一个按钮，用于显示来自Google云端硬盘的数据，用户可以编辑和更新数据，以便更新的数据存储在Google云端硬盘中。 我是Android开发的新手，请帮助我。
我也应用了以下示例但未成功。 https://github.com/seanpjanson/GDAADemo Create / Edit / Retrieve DB file with GDAA (Google Drive Api for Android) Unpredictable result of DriveId.getResourceId() in Google Drive Android API https://github.com/googledrive/android-quickstart
由于
答案 0 :(得分：4)
首先使用以下行在SD卡中创建数据库备份
<强> Driver_utils.create_backup（SettingActivity.this）;
**在build.gradle **
中添加以下依赖项compile 'com.google.code.gson:gson:2.2.+' compile 'com.google.android.gms:play-services-drive:10.0.1'`
in_drive.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if (Utils.isInternetWorking()) {
File directorys = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/Databackup");
if (directorys.exists()) {
String json = preferences_driverId.getString("drive_id", "");
DriveId driveId = gson.fromJson(json, DriveId.class);
//Update file already stored in Drive
Driver_utils.trash(driveId, google_api_client);
// Create the Drive API instance
Driver_utils.creatBackupDrive(SettingActivity.this, google_api_client);
dialog.dismiss();
Toast.makeText(getApplicationContext(), R.string.backupss, Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), R.string.inportfirest, Toast.LENGTH_LONG).show();
}
} else {
Toast.makeText(getApplicationContext(), R.string.nointe, Toast.LENGTH_LONG).show();
}
}
});
**并且对于Restore，请使用此**
restore_from_drive.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// Launch user interface and allow user to select file
IntentSender intentSender = Drive.DriveApi
.newOpenFileActivityBuilder()
.setMimeType(new String[]{"application/zip"})
.build(google_api_client);
try {
startIntentSenderForResult(
intentSender, REQ_CODE_OPEN, null, 0, 0, 0);
} catch (IntentSender.SendIntentException e) {
Log.w(TAG, e.getMessage());
}
dialog.dismiss();
}
});
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == DIALOG_ERROR_CODE) {
mResolvingError = false;
if (resultCode == RESULT_OK) { // Error was resolved, now connect to the client if not done so.
if (!google_api_client.isConnecting() && !google_api_client.isConnected()) {
google_api_client.connect();
}
}
}
if (requestCode == REQ_CODE_OPEN && resultCode == RESULT_OK) {
DriveId mSelectedFileDriveId = data.getParcelableExtra(
OpenFileActivityBuilder.EXTRA_RESPONSE_DRIVE_ID);
Log.e("DriveID ---", mSelectedFileDriveId + "");
Gson gson = new Gson();
String json = gson.toJson(mSelectedFileDriveId); // myObject - instance of MyObject
editor_drive = preferences_driverId.edit();
editor_drive.putString("drive_id", json).commit();
Log.e(TAG, "driveId this 1-- " + mSelectedFileDriveId);
if (Utils.isInternetWorking()) {
//restore Drive file to SDCArd
Driver_utils.restoreDriveBackup(SettingActivity.this, google_api_client, GOOGLE_DRIVE_FILE_NAME, preferences_driverId, mfile);
Driver_utils.restore(SettingActivity.this);
} else {
Toast.makeText(getApplicationContext(), R.string.nointernets, Toast.LENGTH_LONG).show();
}
}
}
**制作一个静态的Driver_utils类**
public class Driver_utils {
public static DriveFile mfile;
public static GoogleApiClient api;
public static DriveId driveId;
public static Context ctxs;
public static SharedPreferences preferences_driverId;
public static SharedPreferences.Editor editor;
private static final String GOOGLE_DRIVE_FILE_NAME = "Databackup";
public static void restoreDriveBackup(Context ctx, GoogleApiClient apis, String GOOGLE_DRIVE_FILE_NAME, SharedPreferences preferences_driverIds, DriveFile mfiles) {
mfile = mfiles;
api = apis;
preferences_driverId = preferences_driverIds;
Query query = new Query.Builder()
.addFilter(Filters.eq(SearchableField.TITLE, GOOGLE_DRIVE_FILE_NAME))
.build();
Drive.DriveApi.query(api, query).setResultCallback(new ResultCallback<DriveApi.MetadataBufferResult>() {
@Override
public void onResult(DriveApi.MetadataBufferResult metadataBufferResult) {
Gson gson = new Gson();
String json = preferences_driverId.getString("drive_id", "");
DriveId driveId = gson.fromJson(json, DriveId.class);
Log.e("driveId put", "" + driveId);
Log.e("filesize in cloud ", +metadataBufferResult.getMetadataBuffer().get(0).getFileSize() + "");
metadataBufferResult.getMetadataBuffer().release();
mfile = Drive.DriveApi.getFile(api, driveId);
mfile.open(api, DriveFile.MODE_READ_ONLY, new DriveFile.DownloadProgressListener() {
@Override
public void onProgress(long bytesDown, long bytesExpected) {
Log.e("Downloading..", "" + bytesDown + "/" + bytesExpected);
}
})
.setResultCallback(restoreContentsCallback);
}
});
}
static final private ResultCallback<DriveApi.DriveContentsResult> restoreContentsCallback =
new ResultCallback<DriveApi.DriveContentsResult>() {
@Override
public void onResult(DriveApi.DriveContentsResult result) {
if (!result.getStatus().isSuccess()) {
Log.e("Unable to open,try", "data");
return;
}
File sd = Environment.getExternalStorageDirectory();
String backupDBPath = "/Databackup.zip";
File imgFile = new File(sd, backupDBPath);
Log.e("FILE EXIST", imgFile.exists() + "");
if (!imgFile.exists())
try {
imgFile.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
imgFile = new File(imgFile.getAbsolutePath());
DriveContents contents = result.getDriveContents();
try {
FileOutputStream fos = new FileOutputStream(imgFile.getAbsolutePath());
BufferedOutputStream bos = new BufferedOutputStream(fos);
BufferedInputStream in = new BufferedInputStream(contents.getInputStream());
byte[] buffer = new byte[1024];
int n, cnt = 0;
while ((n = in.read(buffer)) > 0) {
bos.write(buffer, 0, n);
cnt += n;
Log.e("buffer: ", buffer[0] + "");
Log.e("buffer: ", "" + buffer[1]);
Log.e("buffer: ", "" + buffer[2]);
Log.e("buffer: ", "" + buffer[3]);
bos.flush();
}
bos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
//Unzip when download from drive
try {
String dest_file_path = Environment.getExternalStorageDirectory()
.getAbsolutePath() + "/Databackup";
String src_location = Environment.getExternalStorageDirectory()
.getAbsolutePath() + "/Databackup.zip";
Decompress.unzip(new File(src_location), new File(dest_file_path));
} catch (Exception e) {
e.printStackTrace();
}
}
};
public static void creatBackupDrive(Context ctx, GoogleApiClient apis) {
ctxs = ctx;
api = apis;
Drive.DriveApi.newDriveContents(api).setResultCallback(contentsCallback);
}
final public static ResultCallback<DriveApi.DriveContentsResult> contentsCallback = new ResultCallback<DriveApi.DriveContentsResult>() {
@Override
public void onResult(DriveApi.DriveContentsResult result) {
if (!result.getStatus().isSuccess()) {
Log.e(TAG, "Error while trying to create new file contents");
return;
}
String mimeType = MimeTypeMap.getSingleton().getExtensionFromMimeType("db");
MetadataChangeSet changeSet = new MetadataChangeSet.Builder()
.setTitle(GOOGLE_DRIVE_FILE_NAME) // Google Drive File name
.setMimeType("application/zip")
.setStarred(true).build();
// create a file on root folder
Drive.DriveApi.getRootFolder(api)
.createFile(api, changeSet, result.getDriveContents())
.setResultCallback(fileCallback);
}
};
final public static ResultCallback<DriveFolder.DriveFileResult> fileCallback = new ResultCallback<DriveFolder.DriveFileResult>() {
@Override
public void onResult(DriveFolder.DriveFileResult result) {
preferences_driverId = ctxs.getSharedPreferences("ID", MODE_PRIVATE);
editor = preferences_driverId.edit();
if (!result.getStatus().isSuccess()) {
Log.v(TAG, "Error while trying to create the file");
return;
}
driveId = result.getDriveFile().getDriveId();
Log.e(TAG, "Created a file with content: " + driveId);
Gson gson = new Gson();
String json = gson.toJson(driveId); // myObject - instance of MyObject
editor.putString("drive_id", json).commit();
Log.e(TAG, "driveId " + driveId);
mfile = result.getDriveFile();
mfile.open(api, DriveFile.MODE_WRITE_ONLY, new DriveFile.DownloadProgressListener() {
@Override
public void onProgress(long bytesDownloaded, long bytesExpected) {
Log.e(TAG, "Creating backup file" + bytesDownloaded + "/" + bytesExpected);
}
}).setResultCallback(contentsOpenedCallback);
}
};
final public static ResultCallback<DriveApi.DriveContentsResult> contentsOpenedCallback = new ResultCallback<DriveApi.DriveContentsResult>() {
@Override
public void onResult(DriveApi.DriveContentsResult result) {
if (!result.getStatus().isSuccess()) {
Log.v(TAG, "Error opening file");
return;
}
String sd = Environment.getExternalStorageDirectory().getAbsolutePath() + "/DiaryDatabackup.zip";
Log.e("DB FILE NAME---", sd + "");
DriveContents contents = result.getDriveContents();
BufferedOutputStream out = new BufferedOutputStream(contents.getOutputStream());
byte[] buffer = new byte[1024];
int n;
try {
FileInputStream is = new FileInputStream(sd);
BufferedInputStream in = new BufferedInputStream(is);
while ((n = in.read(buffer)) > 0) {
out.write(buffer, 0, n);
Log.e("Backing up...", "Backup");
}
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
contents.commit(api, null).setResultCallback(new ResultCallback<Status>() {
@Override
public void onResult(Status status) {
Log.e("Backup completed!", "complete"+status);
}
});
}
};
public static void trash(DriveId dId, GoogleApiClient apis) {
api = apis;
try {
Log.e(TAG,"Goes in trans" );
DriveFile sumFile = dId.asDriveFile();
com.google.android.gms.common.api.Status deleteStatus =
sumFile.delete(api).await();
if (!deleteStatus.isSuccess()) {
Log.e(TAG, "Unable to delete app data.");
} else {
// Remove stored DriveId.
preferences_driverId.edit().remove("drive_id").apply();
}
Log.d(TAG, "Past sums deleted.");
} catch (Exception e) {
e.printStackTrace();
}
}
public static void restore(Context ctx) {
OutputStream myOutput;
String dbpath = "//data//" + ctx.getPackageName() + "//databases//databaseName.db";
String sdpath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Databackup";
File directorys = new File(sdpath + "/backup_sd");
if (directorys.exists()) {
try {
myOutput = new FileOutputStream(Environment.getDataDirectory()
+ dbpath);
// Set the folder on the SDcard
File directory = new File(sdpath + "/backup_sd");
// Set the input file stream up:
InputStream myInputs = new FileInputStream(directory.getPath());
// Transfer bytes from the input file to the output file
byte[] buffer = new byte[1024];
int length;
while ((length = myInputs.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close and clear the streams
myOutput.flush();
myOutput.close();
myInputs.close();
Toast.makeText(ctx, R.string.successss, Toast.LENGTH_LONG)
.show();
} catch (FileNotFoundException e) {
Toast.makeText(ctx, ctx.getString(R.string.err), Toast.LENGTH_LONG).show();
e.printStackTrace();
} catch (IOException e) {
Toast.makeText(ctx, ctx.getString(R.string.err), Toast.LENGTH_LONG).show();
// TODO Auto-generated catch block
e.printStackTrace();
}
} else {
Log.e("NO DB YET ", "Created");
Toast.makeText(ctx, R.string.savesome, Toast.LENGTH_LONG).show();
}
}
public static void create_backup(Context ctx) {
InputStream myInput;
String dbpath = "//data//" + ctx.getPackageName() + "//databases//databaseName.db";
String sdpath_createbackup = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Databackup";
File file = new File(sdpath_createbackup);
if (!file.exists())
file.mkdirs();
try {
myInput = new FileInputStream(Environment.getDataDirectory()
+ dbpath);
// Set the output folder on the Scard
File directory = new File(file + "/backup_sd");
// Create the folder if it doesn't exist:
if (!directory.exists()) {
directory.createNewFile();
}
// Set the output file stream up:
OutputStream myOutput = new FileOutputStream(directory.getPath());
// Transfer bytes from the input file to the output file
byte[] buffer = new byte[100024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close and clear the streams
myOutput.flush();
myOutput.close();
myInput.close();
Toast.makeText(ctx, R.string.backups, Toast.LENGTH_LONG)
.show();
} catch (FileNotFoundException e) {
Toast.makeText(ctx, ctx.getString(R.string.err), Toast.LENGTH_LONG).show();
Log.e("error", e.getMessage());
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
Toast.makeText(ctx, ctx.getString(R.string.err), Toast.LENGTH_LONG).show();
Log.e("error 1", e.getMessage());
// TODO Auto-generated catch block
e.printStackTrace();
}
String src_file_path = Environment.getExternalStorageDirectory()
.getAbsolutePath() + "/Databackup";
String destination_location = Environment.getExternalStorageDirectory()
.getAbsolutePath() + "/Databackup.zip";
Decompress.backupfolder(new File(src_file_path), new File(destination_location));
}
}
你需要Decomposer文件才能创建并复制
public class Decompress {
public static boolean unzip(File zipfile, File directory) {
BufferedReader br = null;
try {
ZipFile zfile = new ZipFile(zipfile);
Enumeration<? extends ZipEntry> entries = zfile.entries();
while (entries.hasMoreElements()) {
ZipEntry entry = entries.nextElement();
File file = new File(directory, entry.getName());
if (entry.isDirectory()) {
file.mkdirs();
} else {
file.getParentFile().mkdirs();
InputStream in = zfile.getInputStream(entry);
copy(in, file);
in.close();
}
}
} catch (Exception e) {
e.printStackTrace();
return false;
} finally {
try {
if (br != null) br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
return true;
}
public static boolean backupfolder(File directory, File zipfile) {
try {
URI base = directory.toURI();
Deque<File> queue = new LinkedList<>();
queue.push(directory);
OutputStream out = new FileOutputStream(zipfile);
Closeable res = out;
ZipOutputStream zout = new ZipOutputStream(out);
res = zout;
while (!queue.isEmpty()) {
directory = queue.pop();
for (File kid : directory.listFiles()) {
String name = base.relativize(kid.toURI()).getPath();
if (kid.isDirectory()) {
queue.push(kid);
name = name.endsWith("/") ? name : name + "/";
zout.putNextEntry(new ZipEntry(name));
} else {
zout.putNextEntry(new ZipEntry(name));
copy(kid, zout);
zout.closeEntry();
}
}
}
res.close();
} catch (Exception e) {
e.printStackTrace();
return false;
}
return true;
}
private static void copy(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
while (true) {
int readCount = in.read(buffer);
if (readCount < 0) {
break;
}
out.write(buffer, 0, readCount);
}
}
private static void copy(File file, OutputStream out) throws IOException {
InputStream in = new FileInputStream(file);
try {
copy(in, out);
} finally {
in.close();
}
}
private static void copy(InputStream in, File file) throws IOException {
OutputStream out = new FileOutputStream(file);
try {
copy(in, out);
} finally {
out.close();
}
}
}
答案 1 :(得分：4)
我的回答是假设您有一个密钥库文件来为您的应用签名。如果您没有，this链接会告诉您如何操作。
您需要做的下一件事是下载Android和Google Play服务SDK并获取Android证书，如here所述
现在，您的应用应该可以访问Google云端硬盘API。
在您的活动中，创建这些变量
background-position当用户启动备份过程时，请调用函数 /**
* Handle access to Drive resources/files.
*/
DriveResourceClient mDriveResourceClient;
/**
* Base folder. This is where the backup will be created
*/
DriveFolder baseFolder;
/**
* Request code for google sign-in, to be used for result of Drive sign-in
* Can be any suitable value
*/
protected static final int REQUEST_CODE_SIGN_IN = 0;
/**
* String variables to hold file names, file paths etc.
*/
static final String BACK_UP = <NAME OF BACKUP FILE CREATED ON DRIVE> ;
static final String dbPath = <PATH TO YOUR DATABASE>;
static final String DATABASE_NAME = <NAME OF YOUR DATABASE>;
/*
* This text view is used to show the output from various operations
*/
private TextView tvDriveResult;
singIn() /**
* Starts the sign-in process and initializes the Drive client.
*/
private void singIn() {
Set<Scope> requiredScopes = new HashSet<>(2);
requiredScopes.add(Drive.SCOPE_FILE);
GoogleSignInAccount signInAccount = GoogleSignIn.getLastSignedInAccount(this);
if (signInAccount != null && signInAccount.getGrantedScopes().containsAll(requiredScopes)) {
initializeDriveClient(signInAccount);
} else {
GoogleSignInOptions signInOptions =
new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
.requestScopes(Drive.SCOPE_FILE)
.build();
GoogleSignInClient googleSignInClient = GoogleSignIn.getClient(this, signInOptions);
startActivityForResult(googleSignInClient.getSignInIntent(), REQUEST_CODE_SIGN_IN);
}
}
功能将通过启动Google登录客户端来处理用户登录。您需要处理此客户端的结果。使用以下代码。
singIn()登录成功完成后，通过调用/**
* Handles resolution callbacks.
*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case REQUEST_CODE_SIGN_IN:
if (resultCode != RESULT_OK) {
/* Sign-in may fail or be cancelled by the user. For this sample, sign-in is
* required and is fatal. For apps where sign-in is optional, handle appropriately
*/
Log.e(TAG, "Sign-in failed.");
return;
}
Task<GoogleSignInAccount> getAccountTask =
GoogleSignIn.getSignedInAccountFromIntent(data);
if (getAccountTask.isSuccessful()) {
initializeDriveClient(getAccountTask.getResult());
} else {
Log.e(TAG, "Sign-in failed.");
tvDriveResult.append("Sign-in failed\n");
}
break;
}
super.onActivityResult(requestCode, resultCode, data);
}
功能在上面初始化驱动器客户端。
initializeDriveClient(GoogleSignInAccount signInAccount)设置驱动器客户端后，将调用/**
* Continues the sign-in process, initializing the Drive clients with the current
* user's account.
*/
private void initializeDriveClient(GoogleSignInAccount signInAccount) {
mDriveClient = Drive.getDriveClient(getApplicationContext(), signInAccount);
mDriveResourceClient = Drive.getDriveResourceClient(getApplicationContext(), signInAccount);
onDriveClientReady();
}
。此功能继续创建/恢复您的备份。这里的功能非常简单。获取用户的Google云端硬盘帐户的基本文件夹。湾检查是否存在备份文件。 C。如果是，请将该备份复制到本地数据库文件（over write complete file）。 d。如果不是，请将本地数据库文件复制到用户的Google Drive基本文件夹。如果您愿意，可以为此逻辑添加一些技巧。我的代码是为了帮助您理解这个过程。
onDriveClientReady() /**
* Called after the user has signed in and the Drive client has been initialized.
*/
private void onDriveClientReady(){
/* Initialise the root folder. */
/* Since the tasks are executed in a separate execution threads, the remaining tasks are called from within each other */
getRootFolder();
}
功能如下进行
getRootFolder()这里还有一个名为 private void getRootFolder() {
/* Get the app folder */
Task<DriveFolder> appFolderTask = mDriveResourceClient.getRootFolder();
appFolderTask
.addOnSuccessListener(this, new OnSuccessListener<DriveFolder>() {
@Override
public void onSuccess(DriveFolder driveFolder) {
tvDriveResult.append("Root folder found\n");
baseFolder = driveFolder;
/* Base folder is found, now check if backup file exists */
checkForBackUp();
/* Use this to delete files. Remember to comment out the line able it */
/* listFilesInBaseFolder(); */
}
})
.addOnFailureListener(this, new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
tvDriveResult.append("Root folder not found, error: " + e.toString() + "\n");
}
});
}
的功能，用于删除（永久删除而不是简单地删除）您创建的所有文件。它已被注释掉。如果你想删除你创建的文件，请使用它，请谨慎使用。据我所知，它仅适用于您的应用程序创建的文件。
检查备份。
listFilesInBaseFolder() private void checkForBackUp() {
/* Build a query */
Query query = new Query.Builder()
.addFilter(Filters.eq(SearchableField.TITLE, BACK_UP))
.build();
/* Query contents of app folder */
Task<MetadataBuffer> queryTask = mDriveResourceClient.queryChildren(baseFolder, query);
/* Check for result of query */
queryTask
.addOnSuccessListener(this, new OnSuccessListener<MetadataBuffer>() {
@Override
public void onSuccess(MetadataBuffer metadataBuffer) {
/* if count is 0, the file doesn't exist */
if (metadataBuffer.getCount() == 0){
tvDriveResult.append("File " + BACK_UP + " not found\n");
/* Make file backup */
backUpDatabase();
} else {
tvDriveResult.append(metadataBuffer.getCount() + " Instances of file " + BACK_UP + " found\n");
Metadata metadata = metadataBuffer.get(0);
restoreBackUp(metadata.getDriveId().asDriveFile());
}
}
})
.addOnFailureListener(this, new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
tvDriveResult.append("Could not search for file, error: " + e.toString() + "\n");
}
});
}
将使用Goole Drive上的文件覆盖本地数据库文件。
restoreBackUp(DriveFile driveFile)最后， private void restoreBackUp(DriveFile driveFile) {
tvDriveResult.append("Restoring from backup\n");
/* Get the path of the local backup */
File dbFileOld = new File(dbPath + DATABASE_NAME);
/* Check of dbFileExists on device, delete if it does because it needs to be completely over written */
if (dbFileOld.exists()){
dbFileOld.delete();
}
File dbFileNew = new File(dbPath + DATABASE_NAME);
/* File input stream from database to read from */
final FileOutputStream fileOutputStream;
try {
fileOutputStream = new FileOutputStream(dbFileNew);
} catch (FileNotFoundException e) {
tvDriveResult.append("Could not get input stream from local file\n");
return;
}
/* Task to open file */
Task<DriveContents> openFileTask =
mDriveResourceClient.openFile(driveFile, DriveFile.MODE_READ_ONLY);
/* Continue with task */
openFileTask.continueWithTask(new Continuation<DriveContents, Task<Void>>(){
@Override
public Task<Void> then(@NonNull Task<DriveContents> task) throws Exception {
DriveContents backupContents = task.getResult();
InputStream inputStream = backupContents.getInputStream();
tvDriveResult.append("Attempting to restore from database\n");
byte[] buffer = new byte[4096];
int c;
while ((c = inputStream.read(buffer, 0, buffer.length)) > 0){
fileOutputStream.write(buffer, 0, c);
}
fileOutputStream.flush();
fileOutputStream.close();
fileOutputStream.flush();
fileOutputStream.close();
tvDriveResult.append("Database restored\n");
/* Return statement needed to avoid task failure */
Task<Void> discardTask = mDriveResourceClient.discardContents(backupContents);
return discardTask;
}
})
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
tvDriveResult.append("Could not read file contents\n");
}
});
}
创建了本地数据库的备份。
backUpDatabase()就是这样！这应该让您开始基本操作。我建议您通过Google's Developer Guide进行更深入的潜水。