How to use the setResultCallback method?

问题

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import android.app.Activity;
import android.content.Intent;
import android.content.IntentSender;
import android.content.IntentSender.SendIntentException;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.drive.Drive;
import com.google.android.gms.drive.DriveApi.ContentsResult;
import com.google.android.gms.drive.MetadataChangeSet;


public class Phototodrive extends Activity implements ConnectionCallbacks,
OnConnectionFailedListener{

    private static final String TAG = "android-drive-quickstart";
    private static final int REQUEST_CODE_CAPTURE_IMAGE = 1;
    private static final int REQUEST_CODE_CREATOR = 2;
    private static final int REQUEST_CODE_RESOLUTION = 3;

    private GoogleApiClient mGoogleApiClient;            
    private Bitmap mBitmapToSave;  

    /**
     * Create a new file and save it to Drive. 
     */ 
    private void saveFileToDrive() {  
        // Start by creating a new contents, and setting a callback.
        Log.i(TAG, "Creating new contents.");
        final Bitmap image = mBitmapToSave;  
        Drive.DriveApi.newContents(mGoogleApiClient).setResultCallback(new ResultCallback<ContentsResult>() { 


            public void onResult(ContentsResult result) {
                // If the operation was not successful, we cannot do anything
                // and must
                // fail.
                if (!result.getStatus().isSuccess()) {
                    Log.i(TAG, "Failed to create new contents."); 
                    return; 
                }
                // Otherwise, we can write our data to the new contents.
                Log.i(TAG, "New contents created.");
                // Get an output stream for the contents.
                OutputStream outputStream = result.getContents().getOutputStream();
                // Write the bitmap data from it.
                ByteArrayOutputStream bitmapStream = new ByteArrayOutputStream();
                image.compress(Bitmap.CompressFormat.PNG, 100, bitmapStream);
                try {
                    outputStream.write(bitmapStream.toByteArray());
                } catch (IOException e1) { 
                    Log.i(TAG, "Unable to write file contents.");
                }
                // Create the initial metadata - MIME type and title.
                // Note that the user will be able to change the title later.
                MetadataChangeSet metadataChangeSet = new MetadataChangeSet.Builder()
                        .setMimeType("image/jpeg").setTitle("Android Photo.png").build();
                // Create an intent for the file chooser, and start it.
                IntentSender intentSender = Drive.DriveApi
                        .newCreateFileActivityBuilder() 
                        .setInitialMetadata(metadataChangeSet)
                        .setInitialContents(result.getContents())
                        .build(mGoogleApiClient);
                try {
                    startIntentSenderForResult(
                            intentSender, REQUEST_CODE_CREATOR, null, 0, 0, 0);
                } catch (SendIntentException e) {
                    Log.i(TAG, "Failed to launch file chooser.");
                }
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (mGoogleApiClient == null) {
            // Create the API client and bind it to an instance variable.
            // We use this instance as the callback for connection and connection
            // failures.
            // Since no account name is passed, the user is prompted to choose.
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addApi(Drive.API)
                    .addScope(Drive.SCOPE_FILE)
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .build();
        }
        // Connect the client. Once connected, the camera is launched.
        mGoogleApiClient.connect();
    }

    @Override
    protected void onPause() { 
        if (mGoogleApiClient != null) {
            mGoogleApiClient.disconnect();
        }
        super.onPause();
    }

    @Override
    protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
        switch (requestCode) {
            case REQUEST_CODE_CAPTURE_IMAGE:
                // Called after a photo has been taken.
                if (resultCode == Activity.RESULT_OK) {
                    // Store the image data as a bitmap for writing later.
                    mBitmapToSave = (Bitmap) data.getExtras().get("data");
                }
                break;
            case REQUEST_CODE_CREATOR:
                // Called after a file is saved to Drive.
                if (resultCode == RESULT_OK) {
                    Log.i(TAG, "Image successfully saved.");
                    mBitmapToSave = null;
                    // Just start the camera again for another photo.
                    startActivityForResult(new Intent(MediaStore.ACTION_IMAGE_CAPTURE),
                            REQUEST_CODE_CAPTURE_IMAGE);
                }
                break;
        }
    }

    @Override
    public void onConnectionFailed(ConnectionResult result) {
        // Called whenever the API client fails to connect.
        Log.i(TAG, "GoogleApiClient connection failed: " + result.toString());
        if (!result.hasResolution()) {
            // show the localized error dialog.
            GooglePlayServicesUtil.getErrorDialog(result.getErrorCode(), this, 0).show();
            return;
        }
        // The failure has a resolution. Resolve it.
        // Called typically when the app is not yet authorized, and an
        // authorization
        // dialog is displayed to the user.
        try {
            result.startResolutionForResult(this, REQUEST_CODE_RESOLUTION);
        } catch (SendIntentException e) {
            Log.e(TAG, "Exception while starting resolution activity", e);
        }
    }

    @Override
    public void onConnected(Bundle connectionHint) {
        Log.i(TAG, "API client connected.");
        if (mBitmapToSave == null) {
            // This activity has no UI of its own. Just start the camera.
            startActivityForResult(new Intent(MediaStore.ACTION_IMAGE_CAPTURE),
                    REQUEST_CODE_CAPTURE_IMAGE);
            return;
        }
        saveFileToDrive();
    }

    @Override
    public void onDisconnected() {
        Log.i(TAG, "GoogleApiClient connection suspended");
    }   





}

I`m trying to get the android google drive api quickstart application running.
I get an error like - The method setResultCallback(new ResultCallback(){}) is undefined for the type PendingResult
- ResultCallback cannot be resolved to a type
What should I change, or why I am getting this error?

回答1:

The code looks outdated (Google Play Services lib ver 14) judging by the presence of the 'onDisconnect()'. Check if you have ver 15 (Android SDK Manager) and then try quickstart, demos or this code. And your device should be on Google Play Services 4.2...

来源：https://stackoverflow.com/questions/22489951/how-to-use-the-setresultcallback-method