@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    
    // Add code to print out the key hash
    try {
        PackageInfo info = getPackageManager().getPackageInfo(
                "com.facebook.samples.hellofacebook", 
                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 (NameNotFoundException e) {
        
    } catch (NoSuchAlgorithmException e) {
        
    }
    
    ...

保存更改并重新运行示例。检查你的logcat输出是否有类似这样的消息:

D/KeyHash:(936): 478uEnKQV+fMQT8Dy4AKvHkYibo=

将密钥哈希保存在开发人员配置文件中。重新运行示例并验证可以成功登录。

这就是我如何获得我的:

private class SessionStatusCallback implements Session.StatusCallback {
        @Override
        public void call(Session session, SessionState state, Exception exception) {

            if (exception != null) {
                new AlertDialog.Builder(FriendActivity.this)
                        .setTitle(R.string.login_failed_dialog_title)
                        .setMessage(exception.getMessage())
                        .setPositiveButton(R.string.ok_button, null)
                        .show();
            }

因此，当您试图在没有密钥的情况下输入时，将会出现异常。Facebook在这个例外中加入了RIGHT键。你所要做的就是复制它。

我也遇到了同样的问题，下面是我如何解决它的方法

keytool -list -alias androiddebugkey -keystore <project_file\android\app\debug.keystore>

请试试这个，它对我有用:

fun Context.generateSignKeyHash(): String {

    try {

        val info = packageManager.getPackageInfo(
            packageName,
            PackageManager.GET_SIGNATURES
        )

        for (signature in info.signatures) {
            val md = MessageDigest.getInstance("SHA")
            md.update(signature.toByteArray())
            return Base64.encodeToString(md.digest(), Base64.DEFAULT)
        }

    } catch (e: Exception) {
        Log.e("keyHash", e.message.toString())
    }

    return ""

}

    private fun generateKeyHash(): String? {try {
    val info =packageManager.getPackageInfo(packageName, PackageManager.GET_SIGNATURES)
    for (signature in info.signatures) {
        val md: MessageDigest = MessageDigest.getInstance("SHA")
        md.update(signature.toByteArray())
        return String(Base64.encode(md.digest(), 0))
    }
} catch (e: Exception) {
    Log.e("exception", e.toString())
}
    return "key hash not found"
}

自从API 26以来，你可以在KOTLIN中使用以下代码生成你的HASH key，而不需要任何Facebook SDK。

fun generateSSHKey(context: Context){
    try {
        val info = context.packageManager.getPackageInfo(context.packageName, PackageManager.GET_SIGNATURES)
        for (signature in info.signatures) {
            val md = MessageDigest.getInstance("SHA")
            md.update(signature.toByteArray())
            val hashKey = String(Base64.getEncoder().encode(md.digest()))
            Log.i("AppLog", "key:$hashKey=")
        }
    } catch (e: Exception) {
        Log.e("AppLog", "error:", e)
    }

}