小编Mis*_*ere的帖子

为什么我们TaskStackBuilder在创建通知时使用？我没有得到它背后的逻辑.

有人可以解释一下.

public void showText(final String text){
    Intent intent = new Intent (this, MainActivity.class);
    TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
    stackBuilder.addParentStack(MainActivity.class);
    stackBuilder.addNextIntent(intent);
    PendingIntent pendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);
    Notification notification = new Notification.Builder(this)
            .setSmallIcon(R.mipmap.ic_launcher)
            .setContentTitle(getString(R.string.app_name))
            .setAutoCancel(true)
            .setPriority(Notification.PRIORITY_MAX)
            .setDefaults(Notification.DEFAULT_VIBRATE)
            .setContentIntent(pendingIntent)
            .setContentText(text)
            .build();
    NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.notify(NOTIFICACTION_ID, notification);
}

我正在尝试在菜单栏上实现“搜索窗口小部件”。但是，我收到错误消息：“无法将null强制转换为非null类型的android.widget.SearchView”。但没有结果。

你能给我一些提示吗？

minSdkVersion 17 targetSdkVersion 26

override fun onCreateOptionsMenu(menu: Menu?): Boolean {

        menuInflater.inflate(R.menu.menu, menu)

        val searchView = menu!!.findItem(R.id.app_bar_search).actionView as SearchView
        val searchManager = getSystemService(Context.SEARCH_SERVICE) as SearchManager
        searchView.setSearchableInfo(searchManager.getSearchableInfo(componentName))
        searchView.setOnQueryTextListener(object: SearchView.OnQueryTextListener{
            override fun onQueryTextSubmit(p0: String?): Boolean {
                return false
            }

            override fun onQueryTextChange(p0: String?): Boolean {
                return false
            }

        })

<item
        android:id="@+id/app_bar_search"
        android:actionViewClass="android.widget.SearchView"
        android:icon="@drawable/ic_search_black_24dp"
        android:title="Search"
        app:showAsAction="always"/>