Android kotlin - BottomNavigationView 在 TimerTask

Question

这是有效的代码：

class Stackoverflow : AppCompatActivity() {

    private var menuView: BottomNavigationMenuView? = null

    private var mBottomNavigationView: BottomNavigationView? = null

    private var newmsgTimer: Timer? = null

    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_home)

        mBottomNavigationView = findViewById<View>(R.id.bottom_navigation) as BottomNavigationView

        menuView = mBottomNavigationView!!.getChildAt(0) as BottomNavigationMenuView

        mBottomNavigationView!!.setOnNavigationItemSelectedListener { item ->

            when (item.itemId) {

                R.id.nav_voting -> {

                }

                R.id.nav_search -> {

                }

            }

            return@setOnNavigationItemSelectedListener true

        }

        newmsg()

    }

    private fun newmsg(){

        QBadgeView(this@Stackoverflow).bindTarget(menuView!!.getChildAt(3)).badgeNumber = 7 // IT WORKS HERE

        newmsgTimer = Timer()

        val timerTask = object:TimerTask() {

            override fun run() {

                Log.d("letsSee", "PIKABOO") // it's getting printed

            }

        }

        newmsgTimer!!.schedule(timerTask, 0, 60000)

    }

}

那么它不起作用。

我不知道这个错误是关于什么的：

java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getVisibility()' on a null object reference

        at android.support.design.internal.BottomNavigationMenuView.onMeasure(BottomNavigationMenuView.java:145)

任何想法如何使它在 TimeTask 中工作？提前致谢

编辑：

再次运行后，我也收到此错误：

FATAL EXCEPTION: Timer-1

    Process: com.exmpl.exmpl, PID: 9978

    android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

忽略这一点：需要添加更多单词blabla

Answer 1

您不能直接在另一个线程上更改视图属性，只能在主线程上更改。val timerTask = object : TimerTask() {&nbsp; &nbsp; override fun run() {&nbsp; &nbsp; &nbsp; &nbsp; Log.d("letsSee", "PIKABOO") // it's getting printed&nbsp; &nbsp; &nbsp; &nbsp; menuView.post{&nbsp; &nbsp; &nbsp; QBadgeView(this@Stackoverflow).bindTarget(menuView!!.getChildAt(3)).badgeNumber = 7&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }