代码如下，现在能运行 能安装就是在输入账号密码之后，无法春昂见

class MainActivity : AppCompatActivity(),View.OnClickListener{
    private var mAccount: EditText? = null
    private var mPassword: EditText? = null
    private var mlogin: Button? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        initView()
        ininListener()
    }

    private fun ininListener() {
        mlogin!!.setOnClickListener { v -> handlerLoginEvent(v) }
    }

    private fun handlerLoginEvent(v: View) {
        val accountText = mAccount!!.text.toString()
        val passwordText = mPassword!!.text.toString()
        saveUserInfo(accountText, passwordText)
    }

    private fun saveUserInfo(accountText: String, passwordText: String) {
        Log.d(TAG, "保存了用户信息")
        //        File fileDir=this.getFilesDir();
//        Log.d(TAG,"filesDir==="+fileDir.toString());
        var fileDir=this.getFilesDir();
        Log.d(TAG,"+++++"+fileDir)
        try {
            val file = File("/data/user/0/ymbky.example.suizai/files/info.text")
            if (!file.exists()) {
                file.createNewFile()
            }
            val fos = FileOutputStream(file)
            fos.write("$accountText****$passwordText".toByteArray())
            fos.close()
        } catch (e: Exception) {
            e.printStackTrace()
        }
    }

    private fun initView() {
        mAccount = findViewById(R.id.et_account)
        mPassword = findViewById(R.id.et_password)
        mlogin = findViewById(R.id.bt_login)
    }

    companion object {
        private const val TAG = "MainActivity"
    }

    override fun onClick(v: View?) {
        TODO("Not yet implemented")
    }

 现在经过测试可以确定在 

private fun handlerLoginEvent(v: View) {
        val accountText = mAccount!!.text.toString()
        val passwordText = mPassword!!.text.toString()
        saveUserInfo(accountText, passwordText)
    }
这一步能够拿到输入的账号密码，但是写不出来 ，大佬帮忙看一下