【发布时间】：2013-12-18 17:43:45
【问题描述】：
我已经成功实现了 Google 示例 sdk 中给出的项目，我有一个 .obb 文件，其中包含 2 个文件夹，其中包含图像。
这是我的路
/Android/obb/com.ss.aa/main.1.com.ss.aa.obb
我的 .obb 文件有以下 2 个文件夹
(1)birthdays (2)photos
现在当我运行它时，它将下载我与 .apk 文件一起上传的扩展文件 但是如何显示文件夹中的图像？
以下是我的代码：
public class SampleDownloaderActivity extends Activity implements IDownloaderClient {
private static final String LOG_TAG = "LVLDownloader";
private ProgressBar mPB;
private TextView mStatusText;
private TextView mProgressFraction;
private TextView mProgressPercent;
private TextView mAverageSpeed;
private TextView mTimeRemaining;
private View mDashboard;
private View mCellMessage;
private Button mPauseButton;
private Button mWiFiSettingsButton;
private boolean mStatePaused;
private int mState;
private IDownloaderService mRemoteService;
private IStub mDownloaderClientStub;
private void setState(int newState) {
if (mState != newState) {
mState = newState;
mStatusText.setText(Helpers.getDownloaderStringResourceIDFromState(newState));
}
}
private void setButtonPausedState(boolean paused) {
mStatePaused = paused;
int stringResourceID = paused ? R.string.text_button_resume :
R.string.text_button_pause;
mPauseButton.setText(stringResourceID);
}
/**
* This is a little helper class that demonstrates simple testing of an
* Expansion APK file delivered by Market. You may not wish to hard-code
* things such as file lengths into your executable... and you may wish to
* turn this code off during application development.
*/
private static class XAPKFile {
public final boolean mIsMain;
public final int mFileVersion;
public final long mFileSize;
XAPKFile(boolean isMain, int fileVersion, long fileSize) {
mIsMain = isMain;
mFileVersion = fileVersion;
mFileSize = fileSize;
}
}
/**
* Here is where you place the data that the validator will use to determine
* if the file was delivered correctly. This is encoded in the source code
* so the application can easily determine whether the file has been
* properly delivered without having to talk to the server. If the
* application is using LVL for licensing, it may make sense to eliminate
* these checks and to just rely on the server.
*/
private static final XAPKFile[] xAPKS = {
new XAPKFile(
true, // true signifies a main file
6, // the version of the APK that the file was uploaded
// against
23232840L // the length of the file in bytes
};
/**
* Go through each of the APK Expansion files defined in the structure above
* and determine if the files are present and match the required size. Free
* applications should definitely consider doing this, as this allows the
* application to be launched for the first time without having a network
* connection present. Paid applications that use LVL should probably do at
* least one LVL check that requires the network to be present, so this is
* not as necessary.
*
* @return true if they are present.
*/
boolean expansionFilesDelivered() {
for (XAPKFile xf : xAPKS) {
String fileName = Helpers.getExpansionAPKFileName(this, xf.mIsMain, xf.mFileVersion);
if (!Helpers.doesFileExist(this, fileName, xf.mFileSize, false)) {
return false;
}
}
return true;
}
/**
* Calculating a moving average for the validation speed so we don't get
* jumpy calculations for time etc.
*/
static private final float SMOOTHING_FACTOR = 0.005f;
/**
* Used by the async task
*/
private boolean mCancelValidation;
/**
* Go through each of the Expansion APK files and open each as a zip file.
* Calculate the CRC for each file and return false if any fail to match.
*
* @return true if XAPKZipFile is successful
*/
void validateXAPKZipFiles() {
AsyncTask<Object, DownloadProgressInfo, Boolean> validationTask = new AsyncTask<Object, DownloadProgressInfo, Boolean>() {
@Override
protected void onPreExecute() {
mDashboard.setVisibility(View.VISIBLE);
mCellMessage.setVisibility(View.GONE);
mStatusText.setText(R.string.text_verifying_download);
mPauseButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
mCancelValidation = true;
}
});
mPauseButton.setText(R.string.text_button_cancel_verify);
super.onPreExecute();
}
@Override
protected Boolean doInBackground(Object... params) {
for (XAPKFile xf : xAPKS) {
String fileName = Helpers.getExpansionAPKFileName(
SampleDownloaderActivity.this,
xf.mIsMain, xf.mFileVersion);
if (!Helpers.doesFileExist(SampleDownloaderActivity.this, fileName,
xf.mFileSize, false)) {
return false;
}
fileName = Helpers
.generateSaveFileName(SampleDownloaderActivity.this, fileName);
ZipResourceFile zrf;
byte[] buf = new byte[1024 * 256];
try {
zrf = new ZipResourceFile(fileName);
ZipEntryRO[] entries = zrf.getAllEntries();
/**
* First calculate the total compressed length
*/
long totalCompressedLength = 0;
for (ZipEntryRO entry : entries) {
totalCompressedLength += entry.mCompressedLength;
}
float averageVerifySpeed = 0;
long totalBytesRemaining = totalCompressedLength;
long timeRemaining;
/**
* Then calculate a CRC for every file in the Zip file,
* comparing it to what is stored in the Zip directory.
* Note that for compressed Zip files we must extract
* the contents to do this comparison.
*/
for (ZipEntryRO entry : entries) {
if (-1 != entry.mCRC32) {
long length = entry.mUncompressedLength;
CRC32 crc = new CRC32();
DataInputStream dis = null;
try {
dis = new DataInputStream(
zrf.getInputStream(entry.mFileName));
long startTime = SystemClock.uptimeMillis();
while (length > 0) {
int seek = (int) (length > buf.length ? buf.length
: length);
dis.readFully(buf, 0, seek);
crc.update(buf, 0, seek);
length -= seek;
long currentTime = SystemClock.uptimeMillis();
long timePassed = currentTime - startTime;
if (timePassed > 0) {
float currentSpeedSample = (float) seek
/ (float) timePassed;
if (0 != averageVerifySpeed) {
averageVerifySpeed = SMOOTHING_FACTOR
* currentSpeedSample
+ (1 - SMOOTHING_FACTOR)
* averageVerifySpeed;
} else {
averageVerifySpeed = currentSpeedSample;
}
totalBytesRemaining -= seek;
timeRemaining = (long) (totalBytesRemaining / averageVerifySpeed);
this.publishProgress(
new DownloadProgressInfo(
totalCompressedLength,
totalCompressedLength
- totalBytesRemaining,
timeRemaining,
averageVerifySpeed)
);
}
startTime = currentTime;
if (mCancelValidation) {
return true;
}
}
if (crc.getValue() != entry.mCRC32) {
Log.e(Constants.TAG,
"CRC does not match for entry: "
+ entry.mFileName);
Log.e(Constants.TAG,
"In file: " + entry.getZipFileName());
return false;
}
} finally {
if (null != dis) {
dis.close();
}
}
}
}
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
return true;
}
@Override
protected void onProgressUpdate(DownloadProgressInfo... values) {
onDownloadProgress(values[0]);
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(Boolean result) {
if (result) {
mDashboard.setVisibility(View.VISIBLE);
mCellMessage.setVisibility(View.GONE);
mStatusText.setText(R.string.text_validation_complete);
mPauseButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
finish();
}
});
mPauseButton.setText(android.R.string.ok);
} else {
mDashboard.setVisibility(View.VISIBLE);
mCellMessage.setVisibility(View.GONE);
mStatusText.setText(R.string.text_validation_failed);
mPauseButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
finish();
}
});
mPauseButton.setText(android.R.string.cancel);
}
super.onPostExecute(result);
}
};
validationTask.execute(new Object());
}
/**
* If the download isn't present, we initialize the download UI. This ties
* all of the controls into the remote service calls.
*/
private void initializeDownloadUI() {
mDownloaderClientStub = DownloaderClientMarshaller.CreateStub
(this, SampleDownloaderService.class);
setContentView(R.layout.main);
mPB = (ProgressBar) findViewById(R.id.progressBar);
mStatusText = (TextView) findViewById(R.id.statusText);
mProgressFraction = (TextView) findViewById(R.id.progressAsFraction);
mProgressPercent = (TextView) findViewById(R.id.progressAsPercentage);
mAverageSpeed = (TextView) findViewById(R.id.progressAverageSpeed);
mTimeRemaining = (TextView) findViewById(R.id.progressTimeRemaining);
mDashboard = findViewById(R.id.downloaderDashboard);
mCellMessage = findViewById(R.id.approveCellular);
mPauseButton = (Button) findViewById(R.id.pauseButton);
mWiFiSettingsButton = (Button) findViewById(R.id.wifiSettingsButton);
mPauseButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (mStatePaused) {
mRemoteService.requestContinueDownload();
} else {
mRemoteService.requestPauseDownload();
}
setButtonPausedState(!mStatePaused);
}
});
mWiFiSettingsButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS));
}
});
Button resumeOnCell = (Button) findViewById(R.id.resumeOverCellular);
resumeOnCell.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
mRemoteService.setDownloadFlags(IDownloaderService.FLAGS_DOWNLOAD_OVER_CELLULAR);
mRemoteService.requestContinueDownload();
mCellMessage.setVisibility(View.GONE);
}
});
}
/**
* Called when the activity is first create; we wouldn't create a layout in
* the case where we have the file and are moving to another activity
* without downloading.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
/**
* Both downloading and validation make use of the "download" UI
*/
initializeDownloadUI();
/**
* Before we do anything, are the files we expect already here and
* delivered (presumably by Market) For free titles, this is probably
* worth doing. (so no Market request is necessary)
*/
if (!expansionFilesDelivered()) {
try {
Intent launchIntent = SampleDownloaderActivity.this
.getIntent();
Intent intentToLaunchThisActivityFromNotification = new Intent(
SampleDownloaderActivity
.this, SampleDownloaderActivity.this.getClass());
intentToLaunchThisActivityFromNotification.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
Intent.FLAG_ACTIVITY_CLEAR_TOP);
intentToLaunchThisActivityFromNotification.setAction(launchIntent.getAction());
if (launchIntent.getCategories() != null) {
for (String category : launchIntent.getCategories()) {
intentToLaunchThisActivityFromNotification.addCategory(category);
}
}
// Build PendingIntent used to open this activity from
// Notification
PendingIntent pendingIntent = PendingIntent.getActivity(
SampleDownloaderActivity.this,
0, intentToLaunchThisActivityFromNotification,
PendingIntent.FLAG_UPDATE_CURRENT);
// Request to start the download
int startResult = DownloaderClientMarshaller.startDownloadServiceIfRequired(this,
pendingIntent, SampleDownloaderService.class);
if (startResult != DownloaderClientMarshaller.NO_DOWNLOAD_REQUIRED) {
// The DownloaderService has started downloading the files,
// show progress
initializeDownloadUI();
return;
} // otherwise, download not needed so we fall through to
// starting the movie
} catch (NameNotFoundException e) {
Log.e(LOG_TAG, "Cannot find own package! MAYDAY!");
e.printStackTrace();
}
} else {
validateXAPKZipFiles();
}
}
/**
* Connect the stub to our service on start.
*/
@Override
protected void onStart() {
if (null != mDownloaderClientStub) {
mDownloaderClientStub.connect(this);
}
super.onStart();
}
/**
* Disconnect the stub from our service on stop
*/
@Override
protected void onStop() {
if (null != mDownloaderClientStub) {
mDownloaderClientStub.disconnect(this);
}
super.onStop();
}
/**
* Critical implementation detail. In onServiceConnected we create the
* remote service and marshaler. This is how we pass the client information
* back to the service so the client can be properly notified of changes. We
* must do this every time we reconnect to the service.
*/
@Override
public void onServiceConnected(Messenger m) {
mRemoteService = DownloaderServiceMarshaller.CreateProxy(m);
mRemoteService.onClientUpdated(mDownloaderClientStub.getMessenger());
}
/**
* The download state should trigger changes in the UI --- it may be useful
* to show the state as being indeterminate at times. This sample can be
* considered a guideline.
*/
@Override
public void onDownloadStateChanged(int newState) {
setState(newState);
boolean showDashboard = true;
boolean showCellMessage = false;
boolean paused;
boolean indeterminate;
switch (newState) {
case IDownloaderClient.STATE_IDLE:
// STATE_IDLE means the service is listening, so it's
// safe to start making calls via mRemoteService.
paused = false;
indeterminate = true;
break;
case IDownloaderClient.STATE_CONNECTING:
case IDownloaderClient.STATE_FETCHING_URL:
showDashboard = true;
paused = false;
indeterminate = true;
break;
case IDownloaderClient.STATE_DOWNLOADING:
paused = false;
showDashboard = true;
indeterminate = false;
break;
case IDownloaderClient.STATE_FAILED_CANCELED:
case IDownloaderClient.STATE_FAILED:
case IDownloaderClient.STATE_FAILED_FETCHING_URL:
case IDownloaderClient.STATE_FAILED_UNLICENSED:
paused = true;
showDashboard = false;
indeterminate = false;
break;
case IDownloaderClient.STATE_PAUSED_NEED_CELLULAR_PERMISSION:
case IDownloaderClient.STATE_PAUSED_WIFI_DISABLED_NEED_CELLULAR_PERMISSION:
showDashboard = false;
paused = true;
indeterminate = false;
showCellMessage = true;
break;
case IDownloaderClient.STATE_PAUSED_BY_REQUEST:
paused = true;
indeterminate = false;
break;
case IDownloaderClient.STATE_PAUSED_ROAMING:
case IDownloaderClient.STATE_PAUSED_SDCARD_UNAVAILABLE:
paused = true;
indeterminate = false;
break;
case IDownloaderClient.STATE_COMPLETED:
showDashboard = false;
paused = false;
indeterminate = false;
validateXAPKZipFiles();
return;
default:
paused = true;
indeterminate = true;
showDashboard = true;
}
int newDashboardVisibility = showDashboard ? View.VISIBLE : View.GONE;
if (mDashboard.getVisibility() != newDashboardVisibility) {
mDashboard.setVisibility(newDashboardVisibility);
}
int cellMessageVisibility = showCellMessage ? View.VISIBLE : View.GONE;
if (mCellMessage.getVisibility() != cellMessageVisibility) {
mCellMessage.setVisibility(cellMessageVisibility);
}
mPB.setIndeterminate(indeterminate);
setButtonPausedState(paused);
}
/**
* Sets the state of the various controls based on the progressinfo object
* sent from the downloader service.
*/
@Override
public void onDownloadProgress(DownloadProgressInfo progress) {
mAverageSpeed.setText(getString(R.string.kilobytes_per_second,
Helpers.getSpeedString(progress.mCurrentSpeed)));
mTimeRemaining.setText(getString(R.string.time_remaining,
Helpers.getTimeRemaining(progress.mTimeRemaining)));
//mAverageSpeed.setText("" + Helpers.getSpeedString(progress.mCurrentSpeed));
// mTimeRemaining.setText("" + Helpers.getTimeRemaining(progress.mTimeRemaining));
progress.mOverallTotal = progress.mOverallTotal;
mPB.setMax((int) (progress.mOverallTotal >> 8));
mPB.setProgress((int) (progress.mOverallProgress >> 8));
mProgressPercent.setText(Long.toString(progress.mOverallProgress
* 100 /
progress.mOverallTotal) + "%");
mProgressFraction.setText(Helpers.getDownloadProgressString
(progress.mOverallProgress,
progress.mOverallTotal));
}
@Override
protected void onDestroy() {
this.mCancelValidation = true;
super.onDestroy();
}
}
【问题讨论】：