Question

我在我的android项目中使用listview。为此，我创建了BaseAdapter的子级。但是我遇到错误，应用崩溃了。

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)

    val restaurantListView:ListView? = activity?.findViewById(R.id.restaurant)
    restaurantListView?.adapter = RestaurantAdapter()
    }
}

class RestaurantAdapter:BaseAdapter()
{
override fun getCount(): Int {
return 3
}

override fun getItem(position: Int): Any {
    return Any()
}

override fun getItemId(position: Int): Long {
    return 0
}

override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View? {
    return null
}
}

2019-01-27 19：32：50.372 25975-25975 / com.example.foodtaskerkotlin E / Android运行时：致命异常：主要流程：com.example.foodtaskerkotlin，PID：25975 java.lang.NullPointerException：尝试在空对象引用上调用虚拟方法'int android.view.View.getImportantForAccessibility（）' 在android.widget.AbsListView.obtainView（AbsListView.java:2379）在android.widget.ListView.makeAndAddView（ListView.java:1970）在android.widget.ListView.fillDown（ListView.java:704）在android.widget.ListView.fillFromTop（ListView.java:765）在android.widget.ListView.layoutChildren（ListView.java:1744）在android.widget.AbsListView.onLayout（AbsListView.java:2161）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.widget.LinearLayout.setChildFrame（LinearLayout.java:1741）在android.widget.LinearLayout.layoutVertical（LinearLayout.java:1585）在android.widget.LinearLayout.onLayout（LinearLayout.java:1494）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.widget.FrameLayout.layoutChildren（FrameLayout.java:323）在android.widget.FrameLayout.onLayout（FrameLayout.java:261）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.widget.LinearLayout.setChildFrame（LinearLayout.java:1741）在android.widget.LinearLayout.layoutVertical（LinearLayout.java:1585）在android.widget.LinearLayout.onLayout（LinearLayout.java:1494）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.support.v4.widget.DrawerLayout.onLayout（DrawerLayout.java:1231）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.widget.FrameLayout.layoutChildren（FrameLayout.java:323）在android.widget.FrameLayout.onLayout（FrameLayout.java:261）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.widget.LinearLayout.setChildFrame（LinearLayout.java:1741）在android.widget.LinearLayout.layoutVertical（LinearLayout.java:1585）在android.widget.LinearLayout.onLayout（LinearLayout.java:1494）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.widget.FrameLayout.layoutChildren（FrameLayout.java:323）在android.widget.FrameLayout.onLayout（FrameLayout.java:261）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.widget.LinearLayout.setChildFrame（LinearLayout.java:1741）在android.widget.LinearLayout.layoutVertical（LinearLayout.java:1585）在android.widget.LinearLayout.onLayout（LinearLayout.java:1494）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.widget.FrameLayout.layoutChildren（FrameLayout.java:323）在android.widget.FrameLayout.onLayout（FrameLayout.java:261）在com.android.internal.policy.DecorView.onLayout（DecorView.java:724）在android.view.View.layout（View.java:17523）在android.view.ViewGroup.layout（ViewGroup.java:5612）在android.view.ViewRootImpl.performLayout（ViewRootImpl.java:2342）在android.view.ViewRootImpl.performTraversals（ViewRootImpl.java:2069）在android.view.ViewRootImpl.doTraversal（ViewRootImpl.java:1246）在android.view.ViewRootImpl $ TraversalRunnable.run（ViewRootImpl.java:6301）在android.view.Choreographer $ CallbackRecord.run（Choreographer.java:871）在android.view.Choreographer.doCallbacks（Choreographer.java:683）在android.view.Choreographer.doFrame（Choreographer.java:619）在android.view.Choreographer $ FrameDisplayEventReceiver.run（Choreographer.java:857）在android.os.Handler.handleCallback（Handler.java:751）在android.os.Handler.dispatchMessage（Handler.java:95）在android.os.Looper.loop（Looper.java:154）在android.app.ActivityThread.main（ActivityThread.java:6077）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:866） 2019-01-27 19：32：50.372 25975-25975 / com.example.foodtaskerkotlin E / AndroidRuntime：在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:756）

Kotlin中的基本适配器问题

0 个答案: