我在使用facebook sdk时遇到错误。它给我一个关于OnActivtyResult方法的错误。
请查看下面给出的代码。
这是LogCat结果:
07-05 22:33:51.762 24690-24690/uni.ek.com.re_think E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=64206, result=-1, data=Intent { (has extras) }} to activity {uni.ek.com.re_think/uni.ek.com.re_think.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:3462)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3505)
at android.app.ActivityThread.access$1100(ActivityThread.java:150)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1346)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:5225)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at uni.ek.com.re_think.MainActivity.onActivityResult(MainActivity.java:134)
at android.app.Activity.dispatchActivityResult(Activity.java:5322)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3458)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3505)
at android.app.ActivityThread.access$1100(ActivityThread.java:150)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1346)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:5225)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)
这是MainActivity:
package uni.ek.com.re_think;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.FacebookSdk;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
public class MainActivity extends AppCompatActivity {
EditText name,pass;
Button login;
LoginButton fb_login;
String name1,pass1;
int count,counter;
CallbackManager callbackManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FacebookSdk.sdkInitialize(getApplicationContext());
CallbackManager callbackManager = CallbackManager.Factory.create();
setContentView(R.layout.activity_main);
fb_login= (LoginButton)findViewById(R.id.btnl_fblogin);
//////////////////
fb_login.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
Toast.makeText(getApplicationContext(),"success",Toast.LENGTH_SHORT).show();
}
@Override
public void onCancel() {
}
@Override
public void onError(FacebookException error) {
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
callbackManager.onActivityResult(requestCode, resultCode, data);
}
}
Mainfest.xml
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/app_id"/>
<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" />
<activity android:name=".MainActivity" android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
请解决问题
答案 0 :(得分:1)
callbackManager
始终为null,因为它只是一个局部变量。更改您的onCreate
以填写类字段/成员,如下所示:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FacebookSdk.sdkInitialize(getApplicationContext());
callbackManager = CallbackManager.Factory.create();
//.. the rest of your onCreate