所以我有一个AsyncTask从Mysql数据库中提取数据并显示它，目前这个工作正常，但我需要将简单的适配器更改为自定义适配器，这样我可以用显示的内容做更多。但我不确定我需要更改什么才能使我的自定义适配器与我的AsyncTask一起使用。
public class SearchFor extends AppCompatActivity implements View.OnClickListener {
DBManager db;
ListView lv;
myAdapter myAdapter;
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> attractionList;
ArrayList<HashMap<String, String>> transportList;
// url to get all attraction list
private static String url_all_attractions = "http://10.0.2.2/TravelApp/get_all_attractions.php";
private static String url_all_transport = "http://10.0.2.2/TravelApp/get_all_transport.php";
// JSON Node names for attraction
private static final String TAG_SUCCESS = "success";
private static final String TAG_ATTRACTION = "attraction";
private static final String TAG_ATTRACTIONID = "Id";
private static final String TAG_NAME = "Name";
private static final String TAG_TYPE = "Type";
private static final String TAG_LOCATION = "Location";
private static final String TAG_OPENING = "OpeningTime";
private static final String TAG_CLOSING = "ClosingTime";
private static final String TAG_NEARBYSTOP = "NearbyStop";
private static final String TAG_LATITUDE = "Latitude";
private static final String TAG_LONGITUDE = "Longitude";
//JSON Node names for transport
private static final String TAG_TRANSPORT = "transport";
private static final String TAG_TRANSPORTID = "Id";
private static final String TAG_TIME = "Time";
private static final String TAG_NEXTSTOP = "NextStop";
private static final String TAG_PHONENUMBER = "PhoneNumber";
// attraction JSONArray
JSONArray attraction = null;
JSONArray transport = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search_for);
db = new DBManager(this);
// Hashmap for ListView
attractionList = new ArrayList<HashMap<String, String>>();
transportList = new ArrayList<HashMap<String, String>>();
lv = (ListView) findViewById(R.id.list_search);
this.registerForContextMenu(lv);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
if(v.getId()== R.id.list_search ){
this.getMenuInflater().inflate(R.menu.context_menu_more,menu);
}
}
@Override
public boolean onContextItemSelected(MenuItem item) {
AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
switch (item.getItemId()) {
case R.id.menuBookmark:
testAdd();
break;
case R.id.menuDirections:
break;
default:
return super.onContextItemSelected(item);
}
return false;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.home_button, menu);
getMenuInflater().inflate(R.menu.optionsmenu,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if(id == R.id.go_home){
Intent i = new Intent(getApplicationContext(),QavelNav.class);
startActivity(i);
}
if (item.isChecked())
item.setChecked(false);
else
item.setChecked(true);
if(id == R.id.attractionSub1){
new LoadAllAttractions().execute();
}else if(id == R.id.attractionSub2){
Toast.makeText(getApplicationContext(),"Pubs", Toast.LENGTH_LONG).show();
}else if(id == R.id.attractionSub3){
}else if(id == R.id.attractionSub4){
}else if(id == R.id.transportSub1){
new LoadAllTransport().execute();
}else if(id == R.id.transportSub2){
}
return super.onOptionsItemSelected(item);
}
@Override
public void onClick(View view) {
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View viewClicked,
int position, long id) {
System.out.println(position);
}
});
}
/**
* Background Async Task to Load all product by making HTTP Request
*/
class LoadAllAttractions extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
*/
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(SearchFor.this);
pDialog.setMessage("Loading attractions. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All attraction from url
*/
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_attractions, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Attractions: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// attraction found
// Getting Array of Products
attraction = json.getJSONArray(TAG_ATTRACTION);
// looping through All Products
for (int i = 0; i < attraction.length(); i++) {
JSONObject c = attraction.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ATTRACTIONID);
String name = c.getString(TAG_NAME);
String type = c.getString(TAG_TYPE);
String location = c.getString(TAG_LOCATION);
String opening = c.getString(TAG_OPENING);
String closing = c.getString(TAG_CLOSING);
String nearbyStop1 = c.getString(TAG_NEARBYSTOP);
String latitude = c.getString(TAG_LATITUDE);
String longitude = c.getString(TAG_LONGITUDE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ATTRACTIONID, id);
map.put(TAG_NAME, name);
map.put(TAG_TYPE, type);
map.put(TAG_LOCATION, location);
map.put(TAG_OPENING,opening);
map.put(TAG_CLOSING,closing);
map.put(TAG_NEARBYSTOP, nearbyStop1);
map.put(TAG_LATITUDE, latitude);
map.put(TAG_LONGITUDE, longitude);
// adding HashList to ArrayList
attractionList.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
**/
protected void onPostExecute(String file_url) {
final ArrayList<Adapter> listData = new ArrayList<Adapter>();
listData.clear();
// dismiss the dialog after getting all attraction
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
SearchFor.this, attractionList,
R.layout.list_attractions, new String[]{TAG_ATTRACTIONID,
TAG_NAME,TAG_TYPE,TAG_LOCATION,TAG_OPENING,TAG_CLOSING,TAG_NEARBYSTOP,TAG_LATITUDE,TAG_LONGITUDE},
new int[]{R.id.Attractionid, R.id.tvAttractionName, R.id.tvAttractionType, R.id.tvAttractionLocation,R.id.tvAttractionOpening,R.id.tvAttractionClosing,R.id.tvAttractionNearbyStop1});
// updating listview
//myAdapter = new myAdapter(listData);
lv.setAdapter(adapter);
}
});
}
}
class LoadAllTransport extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
*/
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(SearchFor.this);
pDialog.setMessage("Loading Transport. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All attraction from url
*/
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_transport, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Transport: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// attraction found
// Getting Array of Products
transport = json.getJSONArray(TAG_TRANSPORT);
// looping through All Products
for (int i = 0; i < transport.length(); i++) {
JSONObject c = transport.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_TRANSPORTID);
String name = c.getString(TAG_NAME);
String type = c.getString(TAG_TYPE);
String location = c.getString(TAG_LOCATION);
String time = c.getString(TAG_TIME);
String nextStop = c.getString(TAG_NEXTSTOP);
String phoneNumber = c.getString(TAG_PHONENUMBER);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_TRANSPORTID, id);
map.put(TAG_NAME, name);
map.put(TAG_TYPE, type);
map.put(TAG_LOCATION, location);
map.put(TAG_TIME,time);
map.put(TAG_NEXTSTOP,nextStop);
map.put(TAG_PHONENUMBER, phoneNumber);
// adding HashList to ArrayList
transportList.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
**/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all attraction
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
SearchFor.this, transportList,
R.layout.list_transport, new String[]{TAG_TRANSPORTID,
TAG_NAME,TAG_TYPE,TAG_LOCATION,TAG_TIME,TAG_NEXTSTOP,TAG_PHONENUMBER},
new int[]{R.id.transportid, R.id.tvTransportName, R.id.tvTransportType, R.id.tvTransportLocation,R.id.tvTransportPhone});
// updating listview
lv.setAdapter(adapter);
}
});
}
}
public void testAdd(){
TextView TextName = (TextView)findViewById(R.id.tvAttractionName);
System.out.println(TextName.getText().toString());
}
public void addAttraction(View v){
TextView TextName = (TextView)findViewById(R.id.tvAttractionName);
System.out.println(TextName.getText().toString());
TextView TextType = (TextView) findViewById(R.id.tvAttractionType);
TextView TextLocation = (TextView)findViewById(R.id.tvAttractionLocation);
TextView TextOpening = (TextView)findViewById(R.id.tvAttractionOpening);
TextView TextClosing = (TextView)findViewById(R.id.tvAttractionClosing);
TextView TextNearbyStop = (TextView)findViewById(R.id.tvAttractionNearbyStop1);
ContentValues values = new ContentValues();
values.put(DBManager.ColName,TextName.getText().toString());
values.put(DBManager.ColType,TextType.getText().toString());
values.put(DBManager.ColLocation,TextLocation.getText().toString());
values.put(DBManager.ColOpening,TextOpening.getText().toString());
values.put(DBManager.ColClosing,TextClosing.getText().toString());
values.put(DBManager.ColNearbyStop,TextNearbyStop.getText().toString());
long id = db.Insert("BookmarkAttraction",values);
if (id > 0)
Toast.makeText(getApplicationContext(),"Added to bookmarks", Toast.LENGTH_LONG).show();
else
Toast.makeText(getApplicationContext(),"cannot insert", Toast.LENGTH_LONG).show();
}
public void addTransport(View v){
TextView TextName = (TextView)findViewById(R.id.tvTransportName);
TextView TextType = (TextView) findViewById(R.id.tvTransportType);
TextView TextLocation = (TextView)findViewById(R.id.tvTransportLocation);
TextView TextPhoneNumber = (TextView)findViewById(R.id.tvTransportPhone);
ContentValues values = new ContentValues();
values.put(DBManager.ColName,TextName.getText().toString());
values.put(DBManager.ColType,TextType.getText().toString());
values.put(DBManager.ColLocation,TextLocation.getText().toString());
values.put(DBManager.ColPhoneNumber,TextPhoneNumber.getText().toString());
long id = db.Insert("BookmarkTransport",values);
if (id > 0)
Toast.makeText(getApplicationContext(),"Added to bookmarks", Toast.LENGTH_LONG).show();
else
Toast.makeText(getApplicationContext(),"cannot insert", Toast.LENGTH_LONG).show();
}
class myAdapter extends BaseAdapter {
public ArrayList<Adapter> listItem;
public myAdapter(ArrayList<Adapter> listItem) {
this.listItem = listItem;
}
@Override
public int getCount() {
return listItem.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View view, ViewGroup viewGroup) {
LayoutInflater myInflator = getLayoutInflater();
final View myView = myInflator.inflate(R.layout.list_attractions, null);
final Adapter ac = listItem.get(position);
TextView attractionId = (TextView) myView.findViewById(R.id.Attractionid);
attractionId.setText(ac.ID);
TextView Name = (TextView) myView.findViewById(R.id.tvAttractionName);
Name.setText(ac.Name);
TextView Type = (TextView) myView.findViewById(R.id.tvAttractionType);
Type.setText(ac.Type);
TextView Location = (TextView) myView.findViewById(R.id.tvAttractionLocation);
Location.setText(ac.Location);
TextView Opening = (TextView) myView.findViewById(R.id.tvAttractionOpening);
Opening.setText(ac.Opening);
TextView Closing = (TextView) myView.findViewById(R.id.tvAttractionClosing);
Closing.setText(ac.Closing);
TextView NearbyStop1 = (TextView) myView.findViewById(R.id.tvAttractionNearbyStop1);
NearbyStop1.setText(ac.NearbyStop);
return myView;
}
}
}
感兴趣的部分是位于底部的自定义适配器（myAdapter），第一个AsyncTask是我试图转换为自定义适配器的东西。 onPostExecute是简单适配器的位置，也可能是我需要引用自定义适配器但需要帮助的地方
答案 0 :(得分：0)
似乎您正在使用单个适配器满足您的所有需求。
您是否考虑过为两个AsyncTasks创建两个自定义适配器类。
也很少有建议： 1.您可以使用Loader Callbacks和Cursor loader如果您正在使用AsyncTask进行数据库提取。 2. preExecute和postExecute已在UI线程上运行。所以不需要在那里调用runOnUIThread。 3.在Adapters getView方法中使用ViewHolder模式以获得更好的优化。