这是Xamarin的版本

private void printKeyHash()
{
    try
    {
        PackageInfo info = PackageManager.GetPackageInfo(PackageName, PackageInfoFlags.Signatures);
        foreach (var signature in info.Signatures)
        {
            MessageDigest md = MessageDigest.GetInstance("SHA1");
            md.Update(signature.ToByteArray());
            var hash = Base64.EncodeToString(md.Digest(), Base64Flags.Default);
            Log.Debug("KeyHash:", hash);
        }
    }
    catch (PackageManager.NameNotFoundException e)
    {

    }
    catch (NoSuchAlgorithmException e)
    {

    }
}

在一个类似的问题上，我发现这对我很有效:

将你想知道散列值的apkname.apk文件复制到“Java\jdk1.7.0_79\bin”文件夹中 执行keytool -list -printcert -jarfile apkname.apk 复制SHA1值并使用此站点进行转换 使用转换后的Keyhash值(例如:zaHqo1xcaPv6CmvlWnJk3SaNRIQ=)

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) {

    }
}

要获得Android密钥哈希码，请遵循以下步骤:

下载OpenSSL for Windows 现在解压缩到C盘 打开CMD提示符 输入cd C:\Program Files\Java\ jdk1.6.0_26\bin 然后只输入keytool -export -alias myAlias -keystore c:\ users \您的用户名\。android\myKeyStore | C:\openssl-0.9.8 k_win32 \bin\openssl sha1 -二进制| C:\openssl-0.9.8 k_win32 \bin\openssl enc -a -e 完成

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

在Android Studio中，只需点击右侧侧边栏面板“Gradle”即可显示gardel面板: -YOURAPPNAME ——任务 ——安卓 ----(双击)signingReport(启动Gradle Daemon)

然后你会看到结果:

Config: debug
Store: C:\Users\username\.android\debug.keystore
Alias: AndroidDebugKey
MD5: C8:46:01:EA:36:02:D1:21:1B:23:19:91:D4:32:CB:AC
SHA1: 38:AB:4C:01:01:D7:62:E0:61:D1:9F:52:04:0C:E5:07:4E:E4:9B:39
SHA-256: 1B:8C:DC:35:48:10:01:2C:1F:BD:01:64:F1:01:06:01:60:01:A6:8B:10:15:2E:BF:7B:C4:FD:38:4C:C1:74:01
Valid until: Saturday, February 12, 2050

SHA1副本:

38:AB:4C:01:01:D7:62:E0:68:D1:9F:52:04:0C:E5:07:4E:E4:9B:39

进入本页

粘贴SHA1并生成您的Facebook密钥哈希代码。