java - 在 Android 上使用 Facebook 登录

Question

我正在尝试将“使用 Facebook 登录”功能添加到我的应用程序中，但我遇到了以下问题

1. 当我将 Facebook 登录按钮添加到 XML 时，出现渲染问题(当我刷新布局时问题消失，但再次出现如下所示的白屏)代码:
   <TextView
android:id="@+id/btnLogin"
android:layout_width="wrap_content"
android:layout_height="31dp"
android:layout_gravity="center"
android:layout_marginLeft="175dp"
android:text="Login With Facebook"
android:backgroundTint="#948b8b" />
<com.facebook.login.widget.LoginButton
android:id="@+id/loginButton"
android:visibility="gone"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>

Screen Rendering

1. 当我尝试运行我的应用程序时，我在控制台中看到以下堆栈跟踪信息。

我是 Android 新手，无法解决问题。非常感谢您的帮助。代码:

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
if(PrefUtils.getCurrentUser(LoginActivity.this) != null){
Intent homeIntent = new Intent(LoginActivity.this, MainActivity.class);
startActivity(homeIntent);
finish();
}
}

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.batman.eventmanager, PID: 2111 java.lang.ExceptionInInitializerError at java.lang.reflect.Constructor.newInstance(Native Method) at java.lang.reflect.Constructor.newInstance(Constructor.java:288) at android.view.LayoutInflater.createView(LayoutInflater.java:607) at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:743) at android.view.LayoutInflater.rInflate(LayoutInflater.java:806) at android.view.LayoutInflater.inflate(LayoutInflater.java:504) at android.view.LayoutInflater.inflate(LayoutInflater.java:414) at android.view.LayoutInflater.inflate(LayoutInflater.java:365) at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:378) at android.app.Activity.setContentView(Activity.java:2145) at com.example.batman.eventmanager.LoginActivity.onCreate(LoginActivity.java:33) at android.app.Activity.performCreate(Activity.java:5990) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) at android.app.ActivityThread.access$800(ActivityThread.java:151) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5254) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) Caused by: null at com.facebook.internal.Validate.sdkInitialized(Validate.java:99) at com.facebook.FacebookSdk.getCallbackRequestCodeOffset(FacebookSdk.java:735) at com.facebook.internal.CallbackManagerImpl$RequestCodeOffset.toRequestCode(CallbackManagerImpl.java:109) at com.facebook.login.widget.LoginButton.<clinit>(LoginButton.java:58) at java.lang.reflect.Constructor.newInstance(Native Method)  at java.lang.reflect.Constructor.newInstance(Constructor.java:288)  at android.view.LayoutInflater.createView(LayoutInflater.java:607)  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:743)  at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)  at android.view.LayoutInflater.inflate(LayoutInflater.java:504)  at android.view.LayoutInflater.inflate(LayoutInflater.java:414)  at android.view.LayoutInflater.inflate(LayoutInflater.java:365)  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:378)  at android.app.Activity.setContentView(Activity.java:2145)  at com.example.batman.eventmanager.LoginActivity.onCreate(LoginActivity.java:33)  at android.app.Activity.performCreate(Activity.java:5990)  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387 at android.app.ActivityThread.access$800(ActivityThread.java:151)  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)  at android.os.Handler.dispatchMessage(Handler.java:102)  at android.os.Looper.loop(Looper.java:135)  at android.app.ActivityThread.main(ActivityThread.java:5254)  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:903)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

1. 下面是我的 list XML`

   <activity
       android:name=".LoginActivity"
       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=".MainActivity"
       android:label="@string/app_name"
       android:theme="@style/AppTheme.NoActionBar">
       <intent-filter>
           <action android:name="com.example.batman.eventmanager.MainActivity" />
   
           <category android:name="android.intent.category.DEFAULT" />
       </intent-filter>
   </activity>
   <uses-permission android:name="android.permission.INTERNET"/>
   <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/facebook_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" />
   

   `TIA

Answer 1

您需要在 setContentView()

之前初始化 Facebook sdk

在 setContentView() 之前放置以下代码；

       FacebookSdk.sdkInitialize(getApplicationContext());
       callbackManager = CallbackManager.Factory.create();