【发布时间】：2017-01-09 18:14:38
【问题描述】：
我正在尝试用一个图标和一段文本填充一个列表视图，该文本是从一个具有这两个项目的成员变量的类接收的。
每次在活动中显示列表视图时，应用程序都会崩溃，我看不出它有什么问题。 我确定问题出在自定义数组适配器中，因为我可以初始化和查看标准列表视图没问题，但我看不出这个问题出在哪里。
具有信息的类定义如下：
public class Pokemon {
// core info
String name;
String number;
int no;
int icon;
public Pokemon(String name, int n, int icon){
this.name = name;
this.number = Integer.toString(n);
this.no = n;
this.icon = icon;
}
并在下面实例化为一个ArrayList：
ArrayList<Pokemon> starters = new ArrayList<>();
starters.add(new Pokemon("Bulbasaur", 1, R.drawable.p1)
);
starters.add(new Pokemon("Ivysaur", 2, R.drawable.p2)
);
starters.add(new Pokemon("Venasaur", 3, R.drawable.p3)
);
starters.add(new Pokemon("Charmander", 4, R.drawable.p4)
);
starters.add(new Pokemon("Charmeleon", 5, R.drawable.p5)
);
starters.add(new Pokemon("Charizard", 6, R.drawable.p6)
);
starters.add(new Pokemon("Squirtle", 7, R.drawable.p7)
);
starters.add(new Pokemon("Wartortle", 8, R.drawable.p8)
);
starters.add(new Pokemon("Blastoise", 9, R.drawable.p9)
);
我的自定义适配器是：
public class PokedexArrayAdaptor extends ArrayAdapter<Pokemon>{
Context context;
List<Pokemon> pokemonList;
int layoutResourceId;
public PokedexArrayAdaptor(Context context, int layoutResourceId, ArrayList<Pokemon> objects) {
super(context, layoutResourceId, objects);
this.context = context;
this.layoutResourceId = layoutResourceId;
this.pokemonList = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View rowView = convertView;
PokemonHolder holder;
Pokemon pokemon = pokemonList.get(position);
if(rowView == null){
LayoutInflater vi;
vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
rowView = vi.inflate(layoutResourceId, null);
holder = new PokemonHolder();
holder.name = (TextView)findViewById(R.id.pokemonNameList);
holder.sprite = (ImageView)findViewById(R.id.pokemonIconList);
holder.desc = (TextView)findViewById(R.id.secondLine);
rowView.setTag(holder);
}
else holder = (PokemonHolder)rowView.getTag();
Pokemon pok = pokemonList.get(position);
holder.name.setText(pok.name);
holder.sprite.setImageResource(pokemon.icon);
holder.desc.setText(pok.number);
return rowView;
}
}
在 OnCreate 中，我调用并设置适配器：
customAdaptor = new PokedexArrayAdaptor(this, R.layout.pokedex_entry, starters);
pokedexList = (ListView)findViewById(R.id.pokedexListView);
pokedexList.setAdapter(customAdaptor);
我的 ListView xml 是：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:padding="6dip" >
<ImageView
android:id="@+id/pokemonIconList"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:paddingRight="40dp"
android:paddingLeft="20dp"
android:layout_alignParentBottom="true"
android:layout_alignParentTop="true"
android:layout_marginRight="6dip"
android:contentDescription="TODO"
android:src="@drawable/p1" />
<TextView
android:id="@+id/secondLine"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:ellipsize="marquee"
android:singleLine="true"
android:text="Description"
android:textSize="12sp"
android:layout_toRightOf="@id/pokemonIconList"/>
<TextView
android:id="@+id/pokemonNameList"
android:layout_width="fill_parent"
android:layout_marginTop="10dp"
android:layout_height="wrap_content"
android:layout_above="@id/secondLine"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_alignWithParentIfMissing="true"
android:gravity="center_vertical"
android:text="Example application"
android:textSize="16sp"
android:layout_toRightOf="@id/pokemonIconList"/>
我的活动 xml 是：
<?xml version="1.0" encoding="utf-8"?>
<dallasapps.shinyhunter.SlidingContainer
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFCDD2">
<ListView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/pokedexListView">
</ListView>
</LinearLayout>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/mainTrackScreen"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="dallasapps.shinyhunter.Track"
android:background="#E0E0E0"
android:clickable="true">
<Button
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:id="@+id/sideBtn"
android:visibility="invisible"
android:background="#0000"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="Gen: ORAS"
android:id="@+id/genTxt"
android:layout_centerHorizontal="true"
android:layout_alignParentTop="true"/>
<ImageButton
android:layout_width="55dp"
android:layout_height="55dp"
android:id="@+id/pokedexBtn"
android:background="@drawable/pokedex_xy_icon"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"/>
<ImageView
android:layout_width="match_parent"
android:layout_marginTop="74dp"
android:layout_height="110dp"
android:scaleType="fitCenter"
android:layout_alignParentTop="true"
android:src="@drawable/p8"
android:id="@+id/trackedPokemon"
android:layout_below="@+id/pokedexBtn"
android:layout_centerHorizontal="true"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="24dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="30sp"
android:text="#001 Bulbasaur"
android:id="@+id/pokedexNo"
android:gravity="center_vertical"
android:layout_below="@+id/trackedPokemon"
android:layout_centerHorizontal="true"/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/pokedexNo"
android:layout_marginTop="15dp"
android:layout_centerHorizontal="true"
android:id="@+id/linearLayout">
<Button
android:layout_width="wrap_content"
android:layout_height="80dp"
android:textSize="50sp"
android:text="-"
android:id="@+id/minBtn"
android:background="#F44336"
android:layout_weight="1"/>
<LinearLayout
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<TextView
android:layout_width="180dp"
android:layout_height="wrap_content"
android:textAlignment="center"
android:textSize="40dp"
android:layout_marginTop="5dp"
android:layout_marginBottom="10dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="0"
android:id="@+id/counterTxt"
android:layout_weight="1"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Chance"
android:id="@+id/chance"
android:textAlignment="center"
android:layout_below="@+id/linearLayout"
android:layout_gravity="center_horizontal"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:textSize="30dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="1/4096"
android:id="@+id/chanceTxt"
android:layout_below="@+id/chance"
android:layout_gravity="center"/>
</LinearLayout>
<Button
android:layout_width="wrap_content"
android:layout_height="80dp"
android:textSize="50sp"
android:text="+"
android:id="@+id/plusBtn"
android:background="#F44336"
android:layout_weight="1"
/>
</LinearLayout>
<Button
android:layout_width="70dp"
android:layout_height="70dp"
android:layout_marginTop="-15dp"
android:scaleType="fitCenter"
android:background="#0000"
android:drawableBottom="@drawable/tallgrass"
android:text="Method"
android:id="@+id/methodBtn"
style="?android:attr/borderlessButtonStyle"
android:layout_alignParentTop="true"
android:layout_alignRight="@+id/trackedPokemon"
android:layout_alignEnd="@+id/trackedPokemon"/>
<Button
android:layout_width="wrap_content"
android:layout_height="60dp"
android:textSize="24dp"
android:text="Found"
android:layout_marginBottom="30dp"
android:id="@+id/foundBtn"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"/>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="15dp"
android:id="@+id/scTrackChk"
android:checked="false"
android:layout_alignBottom="@+id/foundBtn"
android:layout_alignLeft="@+id/methodBtn"
android:layout_alignStart="@+id/methodBtn"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="Shiny Charm"
android:id="@+id/scTrackText"
android:layout_below="@+id/scTrackChk"
android:layout_alignRight="@+id/linearLayout"
android:layout_alignEnd="@+id/linearLayout"/>
<ImageView
android:layout_width="30dp"
android:layout_height="30dp"
android:id="@+id/imageView"
android:src="@drawable/shiny_charm"
android:layout_above="@+id/scTrackChk"
android:layout_alignRight="@+id/scTrackChk"
android:layout_alignEnd="@+id/scTrackChk"/>
<ImageView
android:layout_width="30dp"
android:layout_height="30dp"
android:id="@+id/eggTrackImage"
android:src="@drawable/egg"
android:layout_above="@+id/mmTrackChk"
android:layout_alignRight="@+id/mmTrackChk"
android:layout_alignEnd="@+id/mmTrackChk"/>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="15dp"
android:id="@+id/mmTrackChk"
android:checked="false"
android:layout_alignBaseline="@+id/scTrackChk"
android:layout_alignBottom="@+id/scTrackChk"
android:layout_alignRight="@+id/pokedexBtn"
android:layout_alignEnd="@+id/pokedexBtn"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="Masuda"
android:id="@+id/masudaTrackTxt"
android:layout_alignTop="@+id/scTrackText"
android:layout_alignLeft="@+id/pokedexBtn"
android:layout_alignStart="@+id/pokedexBtn"/>
</RelativeLayout>
我似乎根本无法填充列表视图。当我使用标准数组适配器和一个简单的String[] list = {...} 来填充它时它可以工作，所以我确信这是我的自定义适配器的问题，但我不知道如何。
我尝试将持有者减少为仅处理文本值并将其他值设置为每个列表值的常量，但这也不起作用。
有什么想法吗？我遵循了许多在线指南，尝试了覆盖 ArrayAdapter 的不同方法，但没有一个有效。
非常感谢任何帮助。
编辑： 崩溃日志：
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: FATAL EXCEPTION: main
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: Process: dallasapps.shinyhunter, PID: 16121
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at dallasapps.shinyhunter.Track$PokedexArrayAdaptor.getView(Track.java:98)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.AbsListView.obtainView(AbsListView.java:2346)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.ListView.makeAndAddView(ListView.java:1876)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.ListView.fillDown(ListView.java:702)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.ListView.fillFromTop(ListView.java:763)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.ListView.layoutChildren(ListView.java:1685)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.AbsListView.onLayout(AbsListView.java:2148)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.View.layout(View.java:16692)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:5445)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.View.layout(View.java:16692)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:5445)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at dallasapps.shinyhunter.SlidingContainer.onLayout(SlidingContainer.java:70)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.View.layout(View.java:16692)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:5445)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.View.layout(View.java:16692)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:5445)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.support.v7.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:437)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.View.layout(View.java:16692)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:5445)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.View.layout(View.java:16692)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:5445)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.View.layout(View.java:16692)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:5445)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at com.android.internal.policy.PhoneWindow$DecorView.onLayout(PhoneWindow.java:2684)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.View.layout(View.java:16692)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:5445)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2178)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1938)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1114)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6068)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.Choreographer.doCallbacks(Choreographer.java:670)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.Choreographer.doFrame(Choreographer.java:606)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.os.Handler.handleCallback(Handler.java:739)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:95)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.os.Looper.loop(Looper.java:148)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5539)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
01-09 10:21:56.377 16121-16121/dallasapps.shinyhunter D/AppTracker: App Event: crash
【问题讨论】：
-
发生崩溃而你遗漏了最重要的事情.. crashdump / stacktrace。
-
分享您的崩溃日志。这将有很大帮助
标签： java android listview custom-adapter