Question

我想在我的Android应用程序中集成Facebook。

我已按照this link中的步骤进行操作。

MainActivity ：

public class LoginActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        FacebookSdk.sdkInitialize(getApplicationContext());
        setContentView(R.layout.activity_login);

       try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    "com.facebook.samples.loginhowto",
                    PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
            }
        } catch (Exception e) {

        }
    }
}

清单文件：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.facebook.android" >

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <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>

        <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="App_id_Value"/>

    </application>


    <!-- Connect to Internet Permissions -->
    <uses-permission android:name="android.permission.INTERNET"/>


</manifest>

Log cat是：

09-03 13:12:49.240  18433-18433/? E/Zygote﹕ MountEmulatedStorage()
09-03 13:12:49.240  18433-18433/? E/Zygote﹕ v2
09-03 13:12:49.245  18433-18433/? E/SELinux﹕ [DEBUG] get_category: variable seinfo: default sensitivity: NULL, cateogry: NULL
09-03 13:12:49.740  18433-18480/? E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #4
    Process: com.facebook.android, PID: 18433
    java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Object.hashCode()' on a null object reference
            at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:746)
            at java.util.concurrent.ConcurrentHashMap.containsKey(ConcurrentHashMap.java:774)
            at com.facebook.internal.Utility.queryAppSettings(Utility.java:825)
            at com.facebook.login.widget.LoginButton$1.run(LoginButton.java:489)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:818)

Answer 1

问题出在这里

PackageInfo info = getPackageManager().getPackageInfo(
                    "com.facebook.samples.loginhowto",
                    PackageManager.GET_SIGNATURES);

您必须编写清单中指定的应用包。在这种情况下：

PackageInfo info = getPackageManager().getPackageInfo(
                    "com.facebook.android",
                    PackageManager.GET_SIGNATURES);

Answer 2

您在manifest.xml和代码中使用了不同的包名称来生成哈希密钥。

尝试这样：

private void getHashKey() {
    try {
        PackageInfo info = getPackageManager().getPackageInfo(
                getPackageName(), PackageManager.GET_SIGNATURES);
        for (Signature signature : info.signatures) {
            MessageDigest md = MessageDigest.getInstance("SHA");
            md.update(signature.toByteArray());
            Log.d("RAJAT",
                    "KeyHash: "
                            + Base64.encodeToString(md.digest(),
                                    Base64.DEFAULT));
        }
    } catch (NameNotFoundException e) {
    } catch (NoSuchAlgorithmException e) {
    }

}

在Android中集成Facebook时遇到异常

2 个答案: