我正在尝试显示具有不同类型行的 ListView。我有一个由,等Result继承的抽象类。我从 JSON 响应中获取结果。解析没问题，我的工厂设法正确创建了一些对象。ArtistLabelReleaseResult
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;
}
}
}
结果.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);
}
艺术家.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;
}
}
标签.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;
}
}
如您所见，我Artist和Label班级非常相似，但只有我的Label班级在TextView titleText = (TextView) convertView.findViewById(R.id.title_label).
这不是setContentView()我正在做的onCreate。
我的Result对象从来null没有，也没有null字段。
我确实检查了是否convertView在null我的getView方法中，如果有，则对 View 进行膨胀null。
我没有使用 ViewHolder，因为Release并且Master将显示额外的字段。
编辑 ：
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>