下面是我的代码：
基本演示活动：
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 String EXISTING_FOLDER_ID = "CAESHDBCMlBoNlZTdkpaR2FTRTFaWW5wclNXRlFabXMYOiCWqeuO-FI=";
/**
* DriveId of an existing file to be used in file operation samples..
*/
public static final String EXISTING_FILE_ID = "CAESHDBCMlBoNlZTdkpaR2FTRTFaWW5wclNXRlFabXMYOiCWqeuO-FI=";
/**
* 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.
*/
public 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;
}
}
拾取文件夹活动：
public class PickFolderWithOpenerActivity extends BaseDemoActivity {
private static final String TAG = "PickFolderWithOpenerActivity";
private static final int REQUEST_CODE_OPENER = 1;
@Override
public void onConnected(Bundle connectionHint) {
super.onConnected(connectionHint);
IntentSender intentSender = Drive.DriveApi
.newOpenFileActivityBuilder()
.setMimeType(new String[] { DriveFolder.MIME_TYPE })
.build(getGoogleApiClient());
try {
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) {
DriveId driveId = (DriveId) data.getParcelableExtra(
OpenFileActivityBuilder.EXTRA_RESPONSE_DRIVE_ID);
showMessage("Selected folder's ID: " + driveId.getResourceId().toString());
BaseDemoActivity.EXISTING_FOLDER_ID = driveId.getResourceId().toString();
}
finish();
break;
default:
super.onActivityResult(requestCode, resultCode, data);
break;
}
}
}
日志猫：
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=null} to activity {com.drive.testdemo/com.drive.testdemo.PickFolderWithOpenerActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:3432)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3475)
at android.app.ActivityThread.access$1300(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.drive.testdemo.PickFolderWithOpenerActivity.onActivityResult(PickFolderWithOpenerActivity.java:67)
at android.app.Activity.dispatchActivityResult(Activity.java:5446)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3428)
我在连接方面遇到了同样的问题，后来我找到了以下解决方案，
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case REQUEST_CODE_OPENER:
if (resultCode == RESULT_OK) {
final DriveId folderId = (DriveId) data.getParcelableExtra(OpenFileActivityBuilder.EXTRA_RESPONSE_DRIVE_ID);
showMessage("Selected folder's ID: " + folderId);
AsyncTask<Void, Void, Void> task = new AsyncTask<Void, Void, Void>(){
int intReturnType = 0;
@Override
protected void onPostExecute(Void result) {
//super.onPostExecute(result);
//Do Logic...
}
@Override
protected Void doInBackground(Void... params) {
ConnectionResult resultApi = getGoogleApiClient().blockingConnect();
if (!resultApi.isSuccess()) {
return null;
}
@SuppressWarnings("deprecation")
DriveFolder folder = Drive.DriveApi.getFolder(getGoogleApiClient(), folderId);
DriveResource.MetadataResult result = folder.getMetadata(getGoogleApiClient()).await();
if (!result.getStatus().isSuccess()) {
Log.d("Folder", "Problem while trying to fetch metadata.");
return null;
}
Metadata metadata = result.getMetadata();
if (metadata.isTrashed()) {
Log.d("Folder", "Folder is trashed");
return null;
}
Log.d("FolderName", metadata.getTitle());
return null;
}
};
task.execute();
}
break;
default:
super.onActivityResult(requestCode, resultCode, data);
break;
}
}