Question

我有一个带有一些幻灯片的ViewPager。在其中一张幻灯片中，我想要一个ListView，它将由适配器填充。

MyPager.java

public class myPager extends AppCompatActivity {
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_pager_layout);


    viewPager = (ViewPager) findViewById(R.id.view_pager);
    dotsLayout = (LinearLayout) findViewById(R.id.layoutDots);
    btnSkip = (Button) findViewById(R.id.btn_skip);
    btnNext = (Button) findViewById(R.id.btn_next);

    layouts = new int[]{
            R.layout.my_slide1,
            R.layout.my_slide2,
            R.layout.my_slide3};

    //... some code...//
    ArrayList<String> routes = new ArrayList<>();
    ListView routeList = (ListView) findViewById(R.id.routesList);
    ArrayAdapter routeAdaper = new RouteAdapter(this, android.R.layout.simple_list_item_1, routes);
// I get my error here
}}

这是带有ListView的幻灯片。 my_slide3.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <ListView
        android:id="@+id/routesList"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

my_pager_layout.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <LinearLayout
        android:id="@+id/layoutDots"
        android:layout_width="match_parent"
        android:layout_height="@dimen/dots_height"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="@dimen/dots_margin_bottom"
        android:gravity="center"
        android:orientation="horizontal"></LinearLayout>

    <View
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:alpha=".5"
        android:layout_above="@id/layoutDots"
        android:background="@android:color/white" />

    <Button
        android:id="@+id/btn_next"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:background="@null"
        android:text="@string/next"
        android:textColor="@android:color/black" />

    <Button
        android:id="@+id/btn_skip"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:background="@null"
        android:text="@string/skip"
        android:textColor="@android:color/black" />

</RelativeLayout>

getViewById返回null。我假设，因为ListView在View中而不是ContentView。那么获取ListView并为其设置适配器的最佳做法是什么？

来自ViewPager幻灯片的getViewById

0 个答案: