さまざまなタイプの行でListViewを表示しようとしています。、などResultによって継承された抽象クラスがあります。JSON応答から結果を取得しています。解析は問題ありません。私のファクトリはいくつかのオブジェクトを適切に作成することができます。ArtistLabelReleaseResult
これらのガイド1、2を使用して、私は拡張することになりましたBaseAdapter。
public class SearchResultsActivity extends ListActivity {
private static final String SEARCH_API_ENDPOINT = "http://xxxx.com/database/search?q=";
SearchResultAdapter searchAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.result_list);
searchAdapter = new SearchResultAdapter();
// handleIntent is needed because android:launchMode="singleTop" mode uses onNewIntent
handleIntent(getIntent());
}
@Override
protected void onNewIntent(Intent intent) {
handleIntent(intent);
}
private void handleIntent(Intent intent) {
if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
String query = intent.getStringExtra(SearchManager.QUERY); // get user input from search widget
String[][] params = new String[][]{{"q", query}}; // prepare GET parameters
HttpRequestHandler requestHandler = new HttpRequestHandler("GET");
String result;
requestHandler.setURL(HttpRequestHandler.API_URL, HttpRequestHandler.SEARCH_QUERY_ENDPOINT);
requestHandler.addParameters(params);
result = requestHandler.sendRequest();
if (result != null && !result.isEmpty()) {
try {
ArrayList<Result> resultList = new ResultFactory(new JSONObject(result)).getResults(); // JSON to Result objects
for (Result res: resultList) {
searchAdapter.addItem(res);
}
setListAdapter(searchAdapter);
} catch (JSONException e) {
System.out.println("xxjsonexception");
}
}
}
}
public class SearchResultAdapter extends BaseAdapter {
private List<Result> searchResults = new ArrayList<Result>();
private LayoutInflater mInflater;
public SearchResultAdapter() {
mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public void addItem(Result result) {
searchResults.add(result);
notifyDataSetChanged();
}
@Override
public Object getItem(int position) {
return searchResults.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public int getCount() {
return searchResults.size();
}
@Override
public int getViewTypeCount() {
return Result.Type.values().length; // enum length
}
@Override
public int getItemViewType(int position) {
return searchResults.get(position).getType().ordinal();
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Result tmp = searchResults.get(position); // only for testing
System.out.println("xxItem type " + tmp.getType());
View v = searchResults.get(position).getView(mInflater, convertView);
if (v == null) {
System.out.println("xxgetviewnull");
} else {
System.out.println("xxgetviewok");
}
return v;
}
}
}
Result.java：
public abstract class Result {
// general search result class
public enum Type {
ARTIST,
RELEASE,
MASTER,
LABEL,
ERROR,
}
public static final String NODE_RESULTS = "results";
public static final String NODE_TITLE = "title";
public static final String NODE_THUMB = "thumb";
public static final String NODE_RESSOURCE = "resource_url";
public static final String NODE_TYPE = "type";
public static final String NODE_URI = "uri";
public static final String NODE_ID = "id";
public static final String TYPE_ARTIST = "artist";
public static final String TYPE_RELEASE = "release";
public static final String TYPE_MASTER = "master";
public static final String TYPE_LABEL = "label";
protected String thumb;
protected String title;
protected String ressource_url;
protected static Type type;
protected String uri;
protected int id;
public void setData(JSONObject jsonResult) {
try {
setId(jsonResult.getInt(Result.NODE_ID));
setUri(jsonResult.getString(Result.NODE_URI));
setRessource_url(jsonResult.getString(Result.NODE_RESSOURCE));
setThumb(jsonResult.getString(Result.NODE_THUMB));
setTitle(jsonResult.getString(Result.NODE_TITLE));
} catch (JSONException e) {
type = Type.ERROR;
}
}
// getters and setters ..
public abstract View getView(LayoutInflater inflater, View convertView);
}
Artist.java：
public class Artist extends Result{
public Artist(){
type = Type.ARTIST;
}
@Override
public View getView(LayoutInflater inflater, View convertView) {
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_item_artist, null);
}
TextView textTitle = (TextView) convertView.findViewById(R.id.title_artist);
if (textTitle == null) {
System.out.println("xxtexttitle null");
} else {
System.out.println("xxtexttitleok " + title);
}
textTitle.setText(title);
return convertView;
}
}
Label.java
public class Label extends Result {
public Label() {
type = Type.LABEL;
}
@Override
public View getView(LayoutInflater inflater, View convertView) {
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_item_label, null);
}
if (convertView == null) {
System.out.println("xxconvertviewisnull");
} else {
System.out.println("xxconvertviewok");
}
TextView titleText = (TextView) convertView.findViewById(R.id.title_label);
titleText.setText(title);
return convertView;
}
}
ご覧のとおり、私のクラスArtistとクラスは非常に似ていますが、でNPEをスローするのはLabel私のクラスだけです。 LabelTextView titleText = (TextView) convertView.findViewById(R.id.title_label)
これはsetContentView()私がでやっているようではありませんonCreate。
私Resultのオブジェクトは決してフィールドnullを持っていません。私は自分のメソッドにが含まれている
かどうかを確認し、含まれている場合はビューを膨らませます。追加のフィールドが表示されるため、
ViewHolderを使用していません。nullconvertViewnullgetViewnullReleaseMaster
編集 ：
list_item_label.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="@+id/title_label"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
list_item_artist.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="@+id/title_artist"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#FFAAAA"
android:textSize="14pt"/>
</LinearLayout>