如何将对象从一个活动转移到另一个活动（我想转移DropboxAPI的mApi对象 <AndroidAuthSession> ）

Question

i have implemented Parceleble but still it shows error in the putExtra. can anyone help me to figure out what is wrong with the code and how to rectify it.i want to use mApi object in another activity . if any other way is possible then please help me out.

 public class DropboxActivity extends Activity implements Parcelable {
 private static final String TAG = "DropboxActivity";
 final static private String APP_KEY = "----------------";
 final static private String APP_SECRET = "-------------";
 final static private AccessType ACCESS_TYPE = AccessType.APP_FOLDER;
final static private String ACCOUNT_PREFS_NAME = "prefs";
final static private String ACCESS_KEY_NAME = "ACCESS_KEY";
final static private String ACCESS_SECRET_NAME = "ACCESS_SECRET";
DropboxAPI<AndroidAuthSession> mApi;
private boolean mLoggedIn;
private Button mSubmit;
private LinearLayout mDisplay;
private Button upload;
private Button download;
private ImageView mImage;
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    AndroidAuthSession session = buildSession();
    mApi = new DropboxAPI<AndroidAuthSession>(session);
    setContentView(R.layout.main);
    checkAppKeySetup();
    mSubmit = (Button)findViewById(R.id.auth_button);
    mSubmit.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            if (mLoggedIn) {
                logOut();
            } else {
                mApi.getSession().startAuthentication(DropboxActivity.this);
            }
        }
    });
    mDisplay = (LinearLayout)findViewById(R.id.logged_in_display);
    mImage = (ImageView)findViewById(R.id.image_view);
    upload = (Button)findViewById(R.id.upload);
    upload.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
        Intent intent = new Intent("upload");
        intent.putExtra("object", mApi);
        startActivity(intent);
        }
    });
    download = (Button)findViewById(R.id.download);
    setLoggedIn(mApi.getSession().isLinked());
}
@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
}

@Override
protected void onResume() {
    super.onResume();
    AndroidAuthSession session = mApi.getSession();
    if (session.authenticationSuccessful()) {
        try {
            session.finishAuthentication();
            TokenPair tokens = session.getAccessTokenPair();
            storeKeys(tokens.key, tokens.secret);
            setLoggedIn(true);
        } catch (IllegalStateException e) {
            showToast("Couldn't authenticate with Dropbox:" + e.getLocalizedMessage());
            Log.i(TAG, "Error authenticating", e);
        }
    }
}
private void logOut() {
    mApi.getSession().unlink();
    clearKeys();
    setLoggedIn(false);
}
private void setLoggedIn(boolean loggedIn) {
    mLoggedIn = loggedIn;
    if (loggedIn) {
        mSubmit.setText("Unlink from Dropbox");
        mDisplay.setVisibility(View.VISIBLE);
    } else {
        mSubmit.setText("Link with Dropbox");
        mDisplay.setVisibility(View.GONE);
        mImage.setImageDrawable(null);
    }
}

private void checkAppKeySetup() {
    if (APP_KEY.startsWith("CHANGE") ||
            APP_SECRET.startsWith("CHANGE")) {
        showToast("You must apply for an app key and secret from developers.dropbox.com, and add them to the DBRoulette ap before trying it.");
        finish();
        return;
    }
    Intent testIntent = new Intent(Intent.ACTION_VIEW);
    String scheme = "db-" + APP_KEY;
    String uri = scheme + "://" + AuthActivity.AUTH_VERSION + "/test";
    testIntent.setData(Uri.parse(uri));
    PackageManager pm = getPackageManager();
    if (0 == pm.queryIntentActivities(testIntent, 0).size()) {
        showToast("URL scheme in your app's " +
                "manifest is not set up correctly. You should have a " +
                "com.dropbox.client2.android.AuthActivity with the " +
                "scheme: " + scheme);
        finish();
    }
}
private void showToast(String msg) {
    Toast error = Toast.makeText(this, msg, Toast.LENGTH_LONG);
    error.show();
}
private String[] getKeys() {
    SharedPreferences prefs = getSharedPreferences(ACCOUNT_PREFS_NAME, 0);
    String key = prefs.getString(ACCESS_KEY_NAME, null);
    String secret = prefs.getString(ACCESS_SECRET_NAME, null);
    if (key != null && secret != null) {
        String[] ret = new String[2];
        ret[0] = key;
        ret[1] = secret;
        return ret;
    } else {
        return null;
    }
}
private void storeKeys(String key, String secret) {
    // Save the access key for later
    SharedPreferences prefs = getSharedPreferences(ACCOUNT_PREFS_NAME, 0);
    Editor edit = prefs.edit();
    edit.putString(ACCESS_KEY_NAME, key);
    edit.putString(ACCESS_SECRET_NAME, secret);
    edit.commit();
}

private void clearKeys() {
    SharedPreferences prefs = getSharedPreferences(ACCOUNT_PREFS_NAME, 0);
    Editor edit = prefs.edit();
    edit.clear();
    edit.commit();
}

private AndroidAuthSession buildSession() {
    AppKeyPair appKeyPair = new AppKeyPair(APP_KEY, APP_SECRET);
    AndroidAuthSession session;

    String[] stored = getKeys();
    if (stored != null) {
        AccessTokenPair accessToken = new AccessTokenPair(stored[0], stored[1]);
        session = new AndroidAuthSession(appKeyPair, ACCESS_TYPE, accessToken);
    } else {
        session = new AndroidAuthSession(appKeyPair, ACCESS_TYPE);
    }

    return session;
}
@Override
public int describeContents() {
    // TODO Auto-generated method stub
    return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
    // TODO Auto-generated method stub

}

}

Answer 1

I think it is a bad idea to make your activity parcelable. Activities are not supposed to be transported via intents. And if your activities are inside the same application, you do not need transport via intent at all - just stick with standard java mechanisms.