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我一直在這個問題上停留了幾個小時,所以任何幫助都將非常感激。 林收到這個錯誤 嘗試上的空對象引用Android ArrayAdapter中的setAdapter出現Android錯誤
一個ArrayAdapter類
public class LocationsAdapter extends ArrayAdapter<String> {
public LocationsAdapter(Context context, ArrayList<String> locations) {
super(context, R.layout.location_list, locations);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater layoutInflater = LayoutInflater.from(getContext());
View customView = layoutInflater.inflate(R.layout.location_list, parent, false);
String name = getItem(position);
TextView textView = (TextView)customView.findViewById(R.id.locationTF);
textView.setText(name);
return customView;
}
}
調用虛擬方法 '無效android.widget.ListView.setAdapter(android.widget.ListAdapter)'activity_maps.xml
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/listViewLocations" />
location_list.xml
<TextView
android:layout_width="135dp"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:id="@+id/locationTF"
android:layout_weight="0.03" />
MapsActivity類
private ArrayAdapter<String> adapter;
.
.
.
public void initAdapter(){
ArrayList<String> sl = new ArrayList<>();
sl.add("b");
adapter = new LocationsAdapter(this, sl);
ListView listView = (ListView) findViewById(R.id.listViewLocations);
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
}
});
}
請出示您的活動的onCreate方法佈局ID –
的onCreate運行initAdapter() – Bryan
請編輯您的問題...在哪裏做了包含你想找到的列表視圖的XML文件的setContentView? FindViewById可以返回null。這是你的問題 –