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

[EDIT 2020]->现在我完全推荐这里的答案，使用android studio更容易，更快，不需要写任何代码-下面这个是在eclipse时代的:)-。

您可以在任何活动中使用此代码。它将在logcat中记录hashkey，这是调试键。这很简单，而且比使用SSL轻松。

PackageInfo info;
try {
    info = getPackageManager().getPackageInfo("com.you.name", PackageManager.GET_SIGNATURES);
    for (Signature signature : info.signatures) {
        MessageDigest md;
        md = MessageDigest.getInstance("SHA");
        md.update(signature.toByteArray());
        String something = new String(Base64.encode(md.digest(), 0));
        //String something = new String(Base64.encodeBytes(md.digest()));
        Log.e("hash key", something);
    }
} catch (NameNotFoundException e1) {
    Log.e("name not found", e1.toString());
} catch (NoSuchAlgorithmException e) {
    Log.e("no such an algorithm", e.toString());
} catch (Exception e) {
    Log.e("exception", e.toString());
}

你可以在知道密钥后删除代码;)

在Android Studio中也解决了我的问题，但方法略有不同。

在Android Studio中获取SHA-1值。

点击它 点击签署报告 sha - 1副本

SHA-1值是这样的 CD: A1: EA: A3:5C: 5 c: 68: FB:费尔南多-阿隆索:0:6 b: E5:5A: 72:64: DD: 26:8D: 44:84 打开http://tomeko.net/online_tools/hex_to_base64.php进行转换 你的SHA1值到base64。这就是Facebook所要求的 生成的哈希 " ********************= " 并复制关键散列 facebook应用程序控制台。

部分答案来自Github链接

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)
    {

    }
}

你可以从Java/Kotlin Activity中打印哈希键。部分代码已弃用，但这里是包含新旧代码的完整解决方案。

private fun printHashKey(context: Context) {
    try {

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
            val packageInfo: PackageInfo = context.packageManager.getPackageInfo(
                context.packageName,
                PackageManager.GET_SIGNING_CERTIFICATES
            )

            for (signature in packageInfo.signingInfo.apkContentsSigners) {
                val md = MessageDigest.getInstance("SHA")
                md.update(signature.toByteArray())
                Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT))
            }
        } else {
            val packageInfo: PackageInfo = context.packageManager.getPackageInfo(
                context.packageName,
                PackageManager.GET_SIGNATURES
            )

            for (signature in packageInfo.signatures) {
                val md = MessageDigest.getInstance("SHA")
                md.update(signature.toByteArray())
                Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT))
            }
        }

    } catch (e: PackageManager.NameNotFoundException) {
        Log.d(TAG, "printHashKey: PackageManager.NameNotFoundException -> $e")
    } catch (e: NoSuchAlgorithmException) {
        Log.d(TAG, "printHashKey: NoSuchAlgorithmException -> $e")
    }
}

最好的方法是使用以下代码:

private void getHashKey(String pkgName)
{
    try
    {
        PackageInfo info = getPackageManager().getPackageInfo(pkgName, PackageManager.GET_SIGNATURES);
        for (Signature signature : info.signatures)
        {
            MessageDigest md = MessageDigest.getInstance("SHA");
            md.update(signature.toByteArray());
            String hashKey = Base64.encodeBytes(md.digest());
            _hashKey_et.setText(hashKey);
            Log.i("KeyTool", pkgName + " -> hashKey = " + hashKey);
        }
    }
    catch (NameNotFoundException e)
    {
        e.printStackTrace();
    }
    catch (NoSuchAlgorithmException e)
    {
        e.printStackTrace();
    }
}

但我很沮丧，因为没有简单的工具来为Facebook应用程序生成HashKey。每次我都必须使用Openssl和Keytool，或者使用代码从签名中获得哈希值……

所以我写了一个简单的KeyGenTool，将为您做这项工作:-> KeyGenTool谷歌播放<-

享受:)