Facebook登录将无法解析toByteArray（）

Question

我正在构建一个需要Facebook登录和身份验证的应用程序。

我正在关注

https://developers.facebook.com/docs/android/getting-started#create-app

我收到了这个错误：当我点击facebook登录按钮时：

多个帖子说这段代码应该解决错误

Key hash doesn't match while facebook login in android

  try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    "com.hitup.hitup",
                    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)
        {

        }

然而无法解析toByteArray（）方法！

如何解决此错误并为我的应用程序实现简单的Facebook登录？

Answer 1

您必须导入android.content.pm.Signature而不是java.security.Signature。

Answer 2

from Logcat you can get hash key of facebook please do copy from logcat which having Logcat tag "KeyHash" and put it in your project on developer.facebook site 

import android.content.pm.Signature;

      try {
        PackageInfo info = getPackageManager().getPackageInfo(
                **"do not forgot to your package name"**, 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) {

    }



OR 

1. for Android default keystore  : add this to in your terminal 
 
keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore | openssl sha1 -binary | openssl base64

2. for signed keystore 

keytool -exportcert -alias aliasname -keystore keystorename | openssl sha1 -binary | openssl base64