我对Android很新。我试图实现facebook登录，但我面临错误
请告诉我可能是什么问题？
MainActivity.Java
package com.atpata_new;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookSdk;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.facebook.FacebookException;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
public class MainActivity extends Activity {
private TextView info;
private LoginButton loginButton;
private CallbackManager callbackManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FacebookSdk.sdkInitialize(getApplicationContext());
callbackManager = CallbackManager.Factory.create();
setContentView(R.layout.activity_main);
info = (TextView)findViewById(R.id.info);
loginButton = (LoginButton)findViewById(R.id.login_button);
loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
info.setText(
"User ID: "
+ loginResult.getAccessToken().getUserId()
+ "\n" +
"Auth Token: "
+ loginResult.getAccessToken().getToken()
);
}
@Override
public void onCancel() {
info.setText("Login attempt canceled.");
}
@Override
public void onError(FacebookException e) {
info.setText("Login attempt failed.");
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
callbackManager.onActivityResult(requestCode, resultCode, data);
}
}
我得到了以下错误
09-26 01：50：00.783：E / AndroidRuntime（28704）：致命异常：AsyncTask＃5 09-26 01：50：00.783：E / AndroidRuntime（28704）：进程：com.atpata_new，PID：28704 09-26 01：50：00.783：E / AndroidRuntime（28704）：java.lang.NullPointerException 09-26 01：50：00.783：E / AndroidRuntime（28704）：at java.util.concurrent.ConcurrentHashMap.containsKey（ConcurrentHashMap.java:911） 09-26 01：50：00.783：E / AndroidRuntime（28704）：at com.facebook.internal.Utility.queryAppSettings（Utility.java:822） 09-26 01：50：00.783：E / AndroidRuntime（28704）：at com.facebook.login.widget.LoginButton $ 1.run（LoginButton.java:489） 09-26 01：50：00.783：E / AndroidRuntime（28704）：at java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1112） 09-26 01：50：00.783：E / AndroidRuntime（28704）：at java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor.java:587） 09-26 01：50：00.783：E / AndroidRuntime（28704）：at java.lang.Thread.run（Thread.java:841）
Mainfest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.atpata_new"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="23"/>
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.atpata_new.MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.facebook.FacebookActivity"
android:configChanges=
"keyboard|keyboardHidden|screenLayout|screenSize|orientation"
android:theme="@android:style/Theme.Translucent.NoTitleBar"
android:label="@string/app_name" />
</application>
<meta-data android:name="com.facebook.sdk.ApplicationId"
android:value="@string/facebook_app_id"/>
</manifest>
答案 0 :(得分：0)
如果您使用的是Android Studio，请使用Fragment创建空白活动。
让我们说ExampleFragment，我假设您的活动已经创建
public class ExampleFragment extends Fragment {
LoginButton loginButton;
TextView mTextDetails;
private AccessTokenTracker mTokenTracker;
private ProfileTracker mProfileTracker;
private CallbackManager mCallbackManager;
private FacebookCallback<LoginResult> mCallback=new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
AccessToken accessToken = loginResult.getAccessToken();
Profile profile = Profile.getCurrentProfile();
Log.d("Fb Login Success ", "In OnSuccess");
if(profile != null){
Log.d("Message: ", "Welcome "+profile.getName());
}
}
@Override
public void onCancel() {
Log.d("APP", "onCancel");
Toast.makeText(getActivity(), "login via Facebook cancelled by user ", Toast.LENGTH_LONG).show();
}
@Override
public void onError(FacebookException e) {
Log.d("APP", "onError");
Toast.makeText(getActivity(), "Error Occurred!, Unable to login via Facebook, please try again ", Toast.LENGTH_LONG).show();
}
};
//Empty constructor
public ExampleFragment() {
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FacebookSdk.sdkInitialize(getActivity().getApplicationContext());
mCallbackManager=CallbackManager.Factory.create();
setupTokenTracker();
setupProfileTracker();
mTokenTracker.startTracking();
mProfileTracker.startTracking();
}
@Override
public void onResume() {
super.onResume();
Profile profile = Profile.getCurrentProfile();
if(profile != null) {
Log.d("Fb Login Success ", "In OnResume");
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view=inflater.inflate(R.layout.fragment_login, container, false);
return view;
}
public void onViewCreated(View view,Bundle savedInstanceState){
super.onViewCreated(view,savedInstanceState);
loginButton = (LoginButton) view.findViewById(R.id.login_button);
loginButton.setFragment(this);
//loginButton.setBackgroundResource(R.drawable.facebook);
loginButton.setCompoundDrawablesWithIntrinsicBounds(null, null, null, null);
loginButton.setCompoundDrawablePadding(0);
loginButton.setPadding(20, 20, 20, 20);
loginButton.setText("");
loginButton.setWidth(250);
loginButton.setHeight(35);
//loginButton.setCompoundDrawables(null, null, null, null);
loginButton.registerCallback(mCallbackManager, mCallback);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
mCallbackManager.onActivityResult(requestCode, resultCode, data);
}
@Override
public void onStop() {
super.onStop();
mTokenTracker.stopTracking();
mProfileTracker.stopTracking();
}
private void setupTokenTracker() {
mTokenTracker = new AccessTokenTracker() {
@Override
protected void onCurrentAccessTokenChanged(AccessToken oldAccessToken, AccessToken currentAccessToken) {
Log.d("APP currentAccessToken", "" + currentAccessToken);
}
};
}
private void setupProfileTracker() {
mProfileTracker = new ProfileTracker() {
@Override
protected void onCurrentProfileChanged(Profile oldProfile, Profile currentProfile) {
if(currentProfile!=null)
Log.d("APP currentProfile", "" + currentProfile);
Log.d("Fb Login Success ", "In setupProfileTracker");
}
};
}
//End of file
}
在您的活动XML布局
中 <fragment
android:id="@+id/fragment"
android:name="com.example.ExampleFragment"
tools:layout="@layout/fragment_example"
android:layout_width="match_parent"
android:layout_height="match_parent" />
在片段xml布局中，Fragment_example.xml
<com.facebook.login.widget.LoginButton
android:id="@+id/login_button"
style="?android:textAppearanceSmall"
android:layout_width="250dp"
android:layout_height="50dp"
android:text="Facebook"
android:background="#3b5998"
android:textStyle="bold"
android:textColor="@android:color/white"
android:radius="10dp"
/>