Android FaceBook登录 分享获取HashKey（密钥散列）的简单方法

代码执行获取密钥散列：

 try {
            int i = 0;
            PackageInfo info = getPackageManager().getPackageInfo( getPackageName(),  PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                i++;
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                String KeyHash = Base64.encodeToString(md.digest(), Base64.DEFAULT);
                //KeyHash 就是你要的，不用改任何代码  复制粘贴 ;
                Log.e("tyl","KeyHash="+KeyHash);
            }
        }
        catch (PackageManager.NameNotFoundException e) {

        }
        catch (NoSuchAlgorithmException e) {

        }