这是Facebook官方页面上给出的内容:

   keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore | openssl sha1 -binary | openssl base64

让我把这个命令分解成几个片段。

Look for "keytool.exe". You can search that on the C: drive. You can find it in "java jdk" or "java jre". If you have installed multiple versions, choose any. Open a CMD prompt and go to the above directory where you found "keytool.exe". Clip the "exe`" and paste the above command provided on the Facebook page. You will get an error on entering this that OpenSSL is not recognized as in input output command. Solution : Download "Openssl" from OpenSSL (if you have a 64-bit machine you must download openssl-0.9.8e X64). Extract and save it anywhere... I saved it on the C: drive in the OpenSSl folder Replace the openssl in the above command in which you was getting an error of OpenSSL with "C:\OpenSSL\bin\openssl" at both the places after the pipe, "|". If prompted for a password, enter android.

你会得到你的哈希键。要了解进一步的步骤，请再次参考Facebook页面。

This required no coding input. Go to Android Studio-> 
Click on Right side panel "Gradle"=>
*Your App Name =>
*Your App Name(root)=>
*Tasks=>
*android =>
*Double click on **signinReport**=>
Will get 
example :
SHA1: [![6A:DE:ED:5A:9F:0B:19:47:38:DC:DE:3B:7B:A2:D7:4C:6C:0A:24:70][1]][1]

Go to 

http://fbkeyhash.com/index.php
Paste your SHA-1

我只是为这个确切的目的做了一个工具，即https://keyhash.vaibhavpandey.com/。它比其他任何方法都简单，因为它需要您浏览计算机上的密钥存储库，并输入密码，分别为谷歌和Facebook生成SHA-1十六进制和Base64版本。

不必担心密钥库或密码短语，因为工作完全是在浏览器中完成的，您可以检查网络选项卡，该工具也是开源的https://github.com/vaibhavpandeyvpz/keyhash。

试试这个:

两种方法来获得哈希键值

1)从命令行获取哈希键(官方文档:https://developers.facebook.com/docs/android/getting-started)

keytool -exportcert -alias androiddebugkey -keystore %HOMEPATH%\.android\debug.keystore | openssl sha1 -binary | openssl
base64

OR

2)获取哈希键使用代码

  @Override
   protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_main);

            //Hask Kay generation 
             GetKeyHase();
    }

    private void GetKeyHase() {
            try {
                PackageInfo info = getPackageManager().getPackageInfo("ADD YOUR PACKAGE NAME", PackageManager.GET_SIGNATURES);
                for (Signature signature : info.signatures) {
                    MessageDigest md = (MessageDigest.getInstance("SHA"));
                    md.update(signature.toByteArray());
                    String hashkey_value = new String(Base64.encode(md.digest(), 0));
                    Log.e("hash key", hashkey_value);
                    //check you logcat hash key value
                }
            }catch (Exception e) {
                Log.e("exception", e.toString());
            }
        }

对于Android应用程序

这段代码用于在Android应用程序中获取Facebook集成的哈希键。我已经测试了所有的设备，一切正常。只更改此代码的包名:

private void facebookHashKey() {

    try {
        PackageInfo info = getPackageManager().getPackageInfo("com.app.helpcove", PackageManager.GET_SIGNATURES);
        for (Signature signature : info.signatures) {
            MessageDigest md = MessageDigest.getInstance("SHA");
            md.update(signature.toByteArray());
            String hashCode  = Base64.encodeToString(md.digest(), Base64.DEFAULT);
            System.out.println("Print the hashKey for Facebook :"+hashCode);
            Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
        }
    } catch (NameNotFoundException e) {

    } catch (NoSuchAlgorithmException e) {

    }
}

1)创建一个密钥来签署您的应用程序，并记住别名。 2)安装OpenSSL。 3)将OpenSSL的bin文件夹放在您的路径中。 4)按照FB-Android-SDK页面上“设置单点登录”中提到的步骤，生成您的哈希密钥。确保您输入了正确的别名和密钥库文件名。 5)在facebook上创建一个应用程序，在移动设备选项卡下，输入这个哈希密钥。