解析+ Facebook授权：回拨已经注册为<facebook>：com.parse.ParseFacebookUtils

Question

我需要在我的应用程序中通过Parse添加Facebook授权。我遵循https://parse.com/docs/android/guide#users-facebook-users上的说明。但是，如果我运行的应用程序，然后按返回键，然后再次运行它，我总是得到这个错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{.AuthActivity}: java.lang.IllegalStateException: Callback already registered for <facebook>: com.parse.ParseFacebookUtils$1@28d04f8f 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2693) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2758) 
    at android.app.ActivityThread.access$900(ActivityThread.java:177) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1448) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:145) 
    at android.app.ActivityThread.main(ActivityThread.java:5942) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:372) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195) 
Caused by: java.lang.IllegalStateException: Callback already registered for <facebook>: com.parse.ParseFacebookUtils$1@28d04f8f 
    at com.parse.ParseAuthenticationManager.register(ParseAuthenticationManager.java:35) 
    at com.parse.ParseUser.registerAuthenticationCallback(ParseUser.java:1094) 
    at com.parse.ParseFacebookUtils$ParseUserDelegateImpl.registerAuthenticationCallback(ParseFacebookUtils.java:562) 
    at com.parse.ParseFacebookUtils.initialize(ParseFacebookUtils.java:109) 
    at com.parse.ParseFacebookUtils.initialize(ParseFacebookUtils.java:92) 
    at .AuthActivity.onCreate(AuthActivity.java:47) 
    at android.app.Activity.performCreate(Activity.java:6289) 
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2758)  
    at android.app.ActivityThread.access$900(ActivityThread.java:177)  
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1448)  
    at android.os.Handler.dispatchMessage(Handler.java:102)  
    at android.os.Looper.loop(Looper.java:145)  
    at android.app.ActivityThread.main(ActivityThread.java:5942)  
    at java.lang.reflect.Method.invoke(Native Method)  
    at java.lang.reflect.Method.invoke(Method.java:372)  
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)  
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)  

这就是我的活动看起来像：

public class AuthActivity extends AppCompatActivity { 
    … 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     ParseFacebookUtils.initialize(this); // crash here 

     setupEvents(); 

     … 
    } 

    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 
     ParseFacebookUtils.onActivityResult(requestCode, resultCode, data); 
    } 

    private void setupEvents() { 
     findViewById(R.id.fb_login).setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       loginViaFacebook(); 
      } 
     }); 
    } 

    private void loginViaFacebook() { 
     ParseFacebookUtils.logInWithReadPermissionsInBackground(AuthActivity.this, null, new LogInCallback() { 
      @Override 
      public void done(ParseUser user, ParseException err) { 
       … 
      } 
     }); 
    } 
} 

有什么不对吗？

Answer 1

你应该初始化ParseFacebookUtils为应用类，而不是在AppCompatActivity类。

<application 
     android:name=".Configs" 
     ... 

的CONFIGS类是这样的：

public class Configs extends Application { 
… 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    ParseFacebookUtils.initialize(this); 

    … 
} 

您可以创建一个Java类，并调用它CONFIGS，在清单设置它的名字