如何从Google帐户注销并使用Google Drive Android API再次显示帐户选择器

Question

我已经实施了一个代码，用于通过开启器活动从Google云端硬盘Android应用上的Google云端硬盘中打开所选文件。在这个应用程序中，我需要放置注销选项来选择不同的帐户。但是，这段代码只会在登录之后再次登录，我无法从我的应用程序中删除已登录的用户。

是否可以使用Google Drive Android API从Google帐户注销并再次显示帐户选择器？

BaseDemoActivity.java

public abstract class BaseDemoActivity extends Activity implements 
    GoogleApiClient.ConnectionCallbacks, 
    GoogleApiClient.OnConnectionFailedListener { 

private static final String TAG = "BaseDriveActivity"; 

/** 
* DriveId of an existing folder to be used as a parent folder in 
* folder operations samples. 
*/ 
public static final String EXISTING_FOLDER_ID = "folderid"; 

/** 
* DriveId of an existing file to be used in file operation samples.. 
*/ 
public static final String EXISTING_FILE_ID = "fileid"; 

/** 
* Extra for account name. 
*/ 
protected static final String EXTRA_ACCOUNT_NAME = "account_name"; 

/** 
* Request code for auto Google Play Services error resolution. 
*/ 
protected static final int REQUEST_CODE_RESOLUTION = 1; 

/** 
* Next available request code. 
*/ 
protected static final int NEXT_AVAILABLE_REQUEST_CODE = 2; 

/** 
* Google API client. 
*/ 
private GoogleApiClient mGoogleApiClient; 

/** 
* Called when activity gets visible. A connection to Drive services need to 
* be initiated as soon as the activity is visible. Registers 
* {@code ConnectionCallbacks} and {@code OnConnectionFailedListener} on the 
* activities itself. 
*/ 
@Override 
protected void onResume() { 
    super.onResume(); 
    if (mGoogleApiClient == null) { 
     mGoogleApiClient = new GoogleApiClient.Builder(this) 
       .addApi(Drive.API) 
       .addScope(Drive.SCOPE_FILE) 
       .addScope(Drive.SCOPE_APPFOLDER) // required for App Folder sample 
       .addConnectionCallbacks(this) 
       .addOnConnectionFailedListener(this) 
       .build(); 
    } 
    mGoogleApiClient.connect(); 
} 

/** 
* Handles resolution callbacks. 
*/ 
@Override 
protected void onActivityResult(int requestCode, int resultCode, 
     Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 
    if (requestCode == REQUEST_CODE_RESOLUTION && resultCode == RESULT_OK) { 
     mGoogleApiClient.connect(); 
    } 
} 

/** 
* Called when activity gets invisible. Connection to Drive service needs to 
* be disconnected as soon as an activity is invisible. 
*/ 
@Override 
protected void onPause() { 
    if (mGoogleApiClient != null) { 
     mGoogleApiClient.disconnect(); 
    } 
    super.onPause(); 
} 

/** 
* Called when {@code mGoogleApiClient} is connected. 
*/ 
@Override 
public void onConnected(Bundle connectionHint) { 
    Log.i(TAG, "GoogleApiClient connected"); 
} 

/** 
* Called when {@code mGoogleApiClient} is disconnected. 
*/ 
@Override 
public void onConnectionSuspended(int cause) { 
    Log.i(TAG, "GoogleApiClient connection suspended"); 
} 

/** 
* Called when {@code mGoogleApiClient} is trying to connect but failed. 
* Handle {@code result.getResolution()} if there is a resolution is 
* available. 
*/ 
@Override 
public void onConnectionFailed(ConnectionResult result) { 
    Log.i(TAG, "GoogleApiClient connection failed: " + result.toString()); 
    if (!result.hasResolution()) { 
     // show the localized error dialog. 
     GooglePlayServicesUtil.getErrorDialog(result.getErrorCode(), this, 0).show(); 
     return; 
    } 
    try { 
     result.startResolutionForResult(this, REQUEST_CODE_RESOLUTION); 
    } catch (SendIntentException e) { 
     Log.e(TAG, "Exception while starting resolution activity", e); 
    } 
} 

/** 
* Shows a toast message. 
*/ 
public void showMessage(String message) { 
    Toast.makeText(this, message, Toast.LENGTH_LONG).show(); 
} 

/** 
* Getter for the {@code GoogleApiClient}. 
*/ 
public GoogleApiClient getGoogleApiClient() { 
    return mGoogleApiClient; 
} 
} 

MainActivity.java

public class MainActivity extends BaseDemoActivity { 

private static final String TAG = "MainActivity"; 
private static final int RC_SIGN_IN = 0; 
private boolean mIntentInProgress; 
private ConnectionResult mConnectionResult; 
private static final int REQUEST_CODE_OPENER = 1; 
private boolean browsefile = false; 
private boolean mSignInClicked; 
private String FILE_ID; 
TextView filepath; 
Button choosefilebutton; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    choosefilebutton = (Button) findViewById(R.id.choosefilebutton); 
    filepath = (TextView) findViewById(R.id.filepath); 
    choosefilebutton.setOnClickListener(new OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      open(); 
     } 
    }); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    MenuInflater inflater = getMenuInflater(); 
    inflater.inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    switch (item.getItemId()) { 
    case R.id.action_logout: 
     signOutFromGplus(); 
     choosefilebutton.setVisibility(View.GONE); 
    break; 

    default: 
    break; 
    } 

    return true; 
} 

@Override 
public void onConnected(Bundle connectionHint) { 
    super.onConnected(connectionHint); 
    //mSignInClicked = false; 
} 

private void open(){ 
    IntentSender intentSender = Drive.DriveApi 
      .newOpenFileActivityBuilder() 
      .build(getGoogleApiClient()); 
    try { 
     browsefile = true; 
     startIntentSenderForResult(
       intentSender, REQUEST_CODE_OPENER, null, 0, 0, 0); 
    } catch (SendIntentException e) { 
     Log.w(TAG, "Unable to send intent", e); 
    } 
} 

@Override 
protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
    switch (requestCode) { 
    case REQUEST_CODE_OPENER: 
     if (resultCode == RESULT_OK && browsefile == true) { 
      showMessage("Result ok..."); 

      if (!getGoogleApiClient().isConnecting()) { 
       getGoogleApiClient().connect(); 
      } 
      DriveId driveId = (DriveId) data.getParcelableExtra(
        OpenFileActivityBuilder.EXTRA_RESPONSE_DRIVE_ID); 
      showMessage("Selected file's ID: " + driveId.getResourceId()); 
      FILE_ID = driveId.getResourceId(); 
      if(FILE_ID != null){ 
       String link = "https://docs.google.com/file/d/"+FILE_ID; 
       filepath.setText(link); 
       Uri path = Uri.parse(link); 
       Intent intent = new Intent(Intent.ACTION_VIEW); 
       intent.setData(path); 
       intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
       try { 
        startActivity(intent); 
       } catch (Exception e) { 
        showMessage(e.getMessage()); 
       } 
      } 

     } 
     //finish(); 
     break; 
    default: 
     super.onActivityResult(requestCode, resultCode, data); 
    } 
} 

/** 
* Sign-out from google 
* */ 
private void signOutFromGplus() { 
    if (getGoogleApiClient().isConnected()) { 
     getGoogleApiClient().disconnect(); 
     showMessage("Sign out Success..."); 
    } 
} 
} 

Answer 1

看看我的答案在SO 21610239，特别是UPDATE 2014年11月4日部分。