如何解決無法使用谷歌播放服務實例化活動？

Question

我按照這個教程：http://www.androidhive.info/2014/02/android-login-with-google-plus-account-1/

，但我總是得到這個錯誤

08-28 23:37:38.557: E/AndroidRuntime(28591): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.foo.app/com.foo.app.LoginActivity}: java.lang.ClassNotFoundException: Didn't find class "com.foo.app.LoginActivity" on path: DexPathList[[zip file "/data/app/com.foo.app-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.foo.app-2, /vendor/lib, /system/lib]]

爲什麼這個happend？以及如何解決這個問題？ 如果我瀏覽到活動與谷歌播放服務這只是happend進口

清單：

<uses-sdk 
    android:minSdkVersion="14" 
    android:targetSdkVersion="14" /> 

<uses-permission android:name="android.permission.INTERNET" /> 
<uses-permission android:name="android.permission.GET_ACCOUNTS" /> 
<uses-permission android:name="android.permission.USE_CREDENTIALS" /> 

<application 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" > 
    <meta-data 
     android:name="com.google.android.gms.version" 
     android:value="@integer/google_play_services_version" /> 

    <activity 
     android:name="com.foo.app.SplashActivity" 
     android:label="@string/app_name" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
    <activity 
     android:name="com.foo.app.LoginActivity" 
     android:label="@string/app_name" > 
     <intent-filter> 
      <action android:name="com.foo.app.Login" /> 

      <category android:name="android.intent.category.DEFAULT" /> 
     </intent-filter> 
    </activity> 
</application> 

LoginActivity.java

package com.foo.app; 


import java.io.InputStream; 

import android.app.Activity; 
import android.content.Intent; 
import android.content.IntentSender.SendIntentException; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.Menu; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.ImageView; 
import android.widget.LinearLayout; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.google.android.gms.common.ConnectionResult; 
import com.google.android.gms.common.GooglePlayServicesUtil; 
import com.google.android.gms.common.SignInButton; 
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.common.api.ResultCallback; 
import com.google.android.gms.common.api.Status; 
import com.google.android.gms.plus.Plus; 
import com.google.android.gms.plus.model.people.Person; 

public class LoginActivity extends Activity implements OnClickListener, ConnectionCallbacks, OnConnectionFailedListener { 

    private static final int RC_SIGN_IN = 0; 
    // Logcat tag 
    private static final String TAG = "MainActivity"; 

    // Profile pic image size in pixels 
    private static final int PROFILE_PIC_SIZE = 400; 

    // Google client to interact with Google API 
    private GoogleApiClient mGoogleApiClient; 

    /** 
    * A flag indicating that a PendingIntent is in progress and prevents us 
    * from starting further intents. 
    */ 
    private boolean mIntentInProgress; 

    private boolean mSignInClicked; 

    private ConnectionResult mConnectionResult; 

    private SignInButton btnSignIn; 
    private Button btnSignOut, btnRevokeAccess; 
    private ImageView imgProfilePic; 
    private TextView txtName, txtEmail; 
    private LinearLayout llProfileLayout; 

    public void onCreate(Bundle savedInstanceState) { 

     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_login); 

     btnSignIn = (SignInButton) findViewById(R.id.btn_sign_in); 
     btnSignOut = (Button) findViewById(R.id.btn_sign_out); 
     btnRevokeAccess = (Button) findViewById(R.id.btn_revoke_access); 
     imgProfilePic = (ImageView) findViewById(R.id.imgProfilePic); 
     txtName = (TextView) findViewById(R.id.txtName); 
     txtEmail = (TextView) findViewById(R.id.txtEmail); 
     llProfileLayout = (LinearLayout) findViewById(R.id.llProfile); 

     // Button click listeners 
     btnSignIn.setOnClickListener(this); 
     btnSignOut.setOnClickListener(this); 
     btnRevokeAccess.setOnClickListener(this); 

     mGoogleApiClient = new GoogleApiClient.Builder(this) 
       .addConnectionCallbacks(this) 
       .addOnConnectionFailedListener(this).addApi(Plus.API) 
       .addScope(Plus.SCOPE_PLUS_LOGIN).build(); 

    } 

    protected void onStart() { 
     super.onStart(); 
     mGoogleApiClient.connect(); 
    } 

    protected void onStop() { 
     super.onStop(); 
     if (mGoogleApiClient.isConnected()) { 
      mGoogleApiClient.disconnect(); 
     } 
    } 

    /** 
    * Method to resolve any signin errors 
    * */ 
    private void resolveSignInError() { 
     if (mConnectionResult.hasResolution()) { 
      try { 
       mIntentInProgress = true; 
       mConnectionResult.startResolutionForResult(this, RC_SIGN_IN); 
      } catch (SendIntentException e) { 
       mIntentInProgress = false; 
       mGoogleApiClient.connect(); 
      } 
     } 
    } 

    @Override 
    public void onConnectionFailed(ConnectionResult result) { 
     if (!result.hasResolution()) { 
      GooglePlayServicesUtil.getErrorDialog(result.getErrorCode(), this, 
        0).show(); 
      return; 
     } 

     if (!mIntentInProgress) { 
      // Store the ConnectionResult for later usage 
      mConnectionResult = result; 

      if (mSignInClicked) { 
       // The user has already clicked 'sign-in' so we attempt to 
       // resolve all 
       // errors until the user is signed in, or they cancel. 
       resolveSignInError(); 
      } 
     } 

    } 

    @Override 
    protected void onActivityResult(int requestCode, int responseCode, 
      Intent intent) { 
     if (requestCode == RC_SIGN_IN) { 
      if (responseCode != RESULT_OK) { 
       mSignInClicked = false; 
      } 

      mIntentInProgress = false; 

      if (!mGoogleApiClient.isConnecting()) { 
       mGoogleApiClient.connect(); 
      } 
     } 
    } 

    @Override 
    public void onConnected(Bundle arg0) { 
     mSignInClicked = false; 
     Toast.makeText(this, "User is connected!", Toast.LENGTH_LONG).show(); 

     // Get user's information 
     getProfileInformation(); 

     // Update the UI after signin 
     updateUI(true); 

    } 

    /** 
    * Updating the UI, showing/hiding buttons and profile layout 
    * */ 
    private void updateUI(boolean isSignedIn) { 
     if (isSignedIn) { 
      btnSignIn.setVisibility(View.GONE); 
      btnSignOut.setVisibility(View.VISIBLE); 
      btnRevokeAccess.setVisibility(View.VISIBLE); 
      llProfileLayout.setVisibility(View.VISIBLE); 
     } else { 
      btnSignIn.setVisibility(View.VISIBLE); 
      btnSignOut.setVisibility(View.GONE); 
      btnRevokeAccess.setVisibility(View.GONE); 
      llProfileLayout.setVisibility(View.GONE); 
     } 
    } 

    /** 
    * Fetching user's information name, email, profile pic 
    * */ 
    private void getProfileInformation() { 
     try { 
      if (Plus.PeopleApi.getCurrentPerson(mGoogleApiClient) != null) { 
       Person currentPerson = Plus.PeopleApi 
         .getCurrentPerson(mGoogleApiClient); 
       String personName = currentPerson.getDisplayName(); 
       String personPhotoUrl = currentPerson.getImage().getUrl(); 
       String personGooglePlusProfile = currentPerson.getUrl(); 
       String email = Plus.AccountApi.getAccountName(mGoogleApiClient); 

       Log.e(TAG, "Name: " + personName + ", plusProfile: " 
         + personGooglePlusProfile + ", email: " + email 
         + ", Image: " + personPhotoUrl); 

       txtName.setText(personName); 
       txtEmail.setText(email); 

       // by default the profile url gives 50x50 px image only 
       // we can replace the value with whatever dimension we want by 
       // replacing sz=X 
       personPhotoUrl = personPhotoUrl.substring(0, 
         personPhotoUrl.length() - 2) 
         + PROFILE_PIC_SIZE; 

       new LoadProfileImage(imgProfilePic).execute(personPhotoUrl); 

      } else { 
       Toast.makeText(getApplicationContext(), 
         "Person information is null", Toast.LENGTH_LONG).show(); 
      } 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    @Override 
    public void onConnectionSuspended(int arg0) { 
     mGoogleApiClient.connect(); 
     updateUI(false); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

    /** 
    * Button on click listener 
    * */ 
    @Override 
    public void onClick(View v) { 
     switch (v.getId()) { 
     case R.id.btn_sign_in: 
      // Signin button clicked 
      signInWithGplus(); 
      break; 
     case R.id.btn_sign_out: 
      // Signout button clicked 
      signOutFromGplus(); 
      break; 
     case R.id.btn_revoke_access: 
      // Revoke access button clicked 
      revokeGplusAccess(); 
      break; 
     } 
    } 

    /** 
    * Sign-in into google 
    * */ 
    private void signInWithGplus() { 
     if (!mGoogleApiClient.isConnecting()) { 
      mSignInClicked = true; 
      resolveSignInError(); 
     } 
    } 

    /** 
    * Sign-out from google 
    * */ 
    private void signOutFromGplus() { 
     if (mGoogleApiClient.isConnected()) { 
      Plus.AccountApi.clearDefaultAccount(mGoogleApiClient); 
      mGoogleApiClient.disconnect(); 
      mGoogleApiClient.connect(); 
      updateUI(false); 
     } 
    } 

    /** 
    * Revoking access from google 
    * */ 
    private void revokeGplusAccess() { 
     if (mGoogleApiClient.isConnected()) { 
      Plus.AccountApi.clearDefaultAccount(mGoogleApiClient); 
      Plus.AccountApi.revokeAccessAndDisconnect(mGoogleApiClient) 
        .setResultCallback(new ResultCallback<Status>() { 
         @Override 
         public void onResult(Status arg0) { 
          Log.e(TAG, "User access revoked!"); 
          mGoogleApiClient.connect(); 
          updateUI(false); 
         } 

        }); 
     } 
    } 

    /** 
    * Background Async task to load user profile picture from url 
    * */ 
    private class LoadProfileImage extends AsyncTask<String, Void, Bitmap> { 
     ImageView bmImage; 

     public LoadProfileImage(ImageView bmImage) { 
      this.bmImage = bmImage; 
     } 

     protected Bitmap doInBackground(String... urls) { 
      String urldisplay = urls[0]; 
      Bitmap mIcon11 = null; 
      try { 
       InputStream in = new java.net.URL(urldisplay).openStream(); 
       mIcon11 = BitmapFactory.decodeStream(in); 
      } catch (Exception e) { 
       Log.e("Error", e.getMessage()); 
       e.printStackTrace(); 
      } 
      return mIcon11; 
     } 

     protected void onPostExecute(Bitmap result) { 
      bmImage.setImageBitmap(result); 
     } 
    } 
} 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical" 
    android:padding="16dp" 
    tools:context=".LoginActivity" > 

    <LinearLayout 
     android:id="@+id/llProfile" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_marginBottom="20dp" 
     android:orientation="horizontal" 
     android:weightSum="3" 
     android:visibility="gone"> 

     <ImageView 
      android:id="@+id/imgProfilePic" 
      android:layout_width="80dp" 
      android:layout_height="wrap_content" 
      android:layout_weight="1"/> 

     <LinearLayout 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_marginLeft="10dp" 
      android:orientation="vertical" 
      android:layout_weight="2" > 

      <TextView 
       android:id="@+id/txtName" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:padding="5dp" 
       android:textSize="20dp" /> 

      <TextView 
       android:id="@+id/txtEmail" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:padding="5dp" 
       android:textSize="18dp" /> 
     </LinearLayout> 
    </LinearLayout> 

    <com.google.android.gms.common.SignInButton 
     android:id="@+id/btn_sign_in" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_marginBottom="20dp"/> 

    <Button 
     android:id="@+id/btn_sign_out" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:text="@string/btn_logout_from_google" 
     android:visibility="gone" 
     android:layout_marginBottom="10dp"/> 

    <Button 
     android:id="@+id/btn_revoke_access" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:text="@string/btn_revoke_access" 
     android:visibility="gone" /> 

</LinearLayout> 

，這是我如何瀏覽

startActivity(new Intent("com.foo.app.Login")); 
    finish(); 

我的錯誤：

08-29 13:31:55.668: E/AndroidRuntime(9232): FATAL EXCEPTION: main 08-29 13:31:55.668: E/AndroidRuntime(9232): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.foo.app/com.foo.app.LoginActivity}: java.lang.ClassNotFoundException: Didn't find class "com.foo.app.LoginActivity" on path: DexPathList[[zip file "/data/app/com.foo.app-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.foo.app-1, /vendor/lib, /system/lib]] 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140) 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2264) 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.app.ActivityThread.access$600(ActivityThread.java:144) 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1259) 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.os.Handler.dispatchMessage(Handler.java:99) 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.os.Looper.loop(Looper.java:137) 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.app.ActivityThread.main(ActivityThread.java:5152) 08-29 13:31:55.668: E/AndroidRuntime(9232): at java.lang.reflect.Method.invokeNative(Native Method) 08-29 13:31:55.668: E/AndroidRuntime(9232): at java.lang.reflect.Method.invoke(Method.java:525) 08-29 13:31:55.668: E/AndroidRuntime(9232): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:744) 08-29 13:31:55.668: E/AndroidRuntime(9232): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 08-29 13:31:55.668: E/AndroidRuntime(9232): at dalvik.system.NativeStart.main(Native Method) 08-29 13:31:55.668: E/AndroidRuntime(9232): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.foo.app.LoginActivity" on path: DexPathList[[zip file "/data/app/com.foo.app-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.foo.app-1, /vendor/lib, /system/lib]] 08-29 13:31:55.668: E/AndroidRuntime(9232): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53) 08-29 13:31:55.668: E/AndroidRuntime(9232): at java.lang.ClassLoader.loadClass(ClassLoader.java:501) 08-29 13:31:55.668: E/AndroidRuntime(9232): at java.lang.ClassLoader.loadClass(ClassLoader.java:461) 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.app.Instrumentation.newActivity(Instrumentation.java:1061) 08-29 13:31:55.668: E/AndroidRuntime(9232): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2131) 08-29 13:31:55.668: E/AndroidRuntime(9232): ... 11 more

Answer 1

startActivity(new Intent(calleractivty.this, LoginActivity.class)); 

，並在清單

<activity android:name=".SplashActivity" ... 

如果你看看和堆疊

Unable to instantiate activity ComponentInfo{com.foo.app/com.foo.app.LoginActivity}: it tries to reach wrong path

那麼它應該工作。