将列表视图从旧值刷新为新值时出现问题。通过几个小时的搜索，我得到了那个adapter.notifyDataSetChanged(); 必须使用。但我无法理解如何使用它，因为每当我使用它时都会出现错误
“未为 ListAdapter 类型定义方法 notifyDataSetChanged()”
我不确定我是否做对了。请帮忙...
这是我的代码
public class Slider extends Activity implements OnClickListener,
OnDrawerOpenListener, OnDrawerCloseListener {
Button mCloseButton;
Button mOpenButton;
MultiDirectionSlidingDrawer mDrawer;
ListView list;
TextView t1;
String data, query, is;
Spinner d;
String FILENAME = "http://24.php";
ArrayList<String> pos;
ListAdapter adapter;
ArrayList<HashMap<String, String>> mylist;
HashMap<String, String> map;
static String j_id = null;
static Object j_make = null;
static String j_model = null;
static String j_version = null;
static String j_price = null;
static String j_reg_plc = null;
String ID = "car_id";
String MAKE = "make";
String MODEL = "model";
String VERSION = "version";
String PRICE = "expected_price";
String PLACE_REG = "registration_place";
CheckBox cb1, cb2, cb3, cb4, cb5, cb6, cb7, cb8, cb9, cb10;
Spinner sp1;
int flag = 0;
String drive[] = new String[] { "Select Drive", "Two-Wheel Drive",
"Four-Wheel Drive", "All-Wheel Drive" };
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.slider);
t1 = (TextView) findViewById(R.id.noRec);
list = (ListView) findViewById(R.id.listView1);
cb1 = (CheckBox) findViewById(R.id.checkBox1);
cb2 = (CheckBox) findViewById(R.id.checkBox2);
cb3 = (CheckBox) findViewById(R.id.checkBox3);
cb4 = (CheckBox) findViewById(R.id.checkBox4);
cb5 = (CheckBox) findViewById(R.id.checkBox5);
cb6 = (CheckBox) findViewById(R.id.checkBox6);
cb7 = (CheckBox) findViewById(R.id.checkBox7);
cb8 = (CheckBox) findViewById(R.id.checkBox8);
cb9 = (CheckBox) findViewById(R.id.checkBox9);
cb10 = (CheckBox) findViewById(R.id.checkBox10);
d = (Spinner) findViewById(R.id.drive);
@SuppressWarnings("unchecked")
ArrayAdapter spdrv = new ArrayAdapter(this,
android.R.layout.simple_spinner_item, drive);
d.setAdapter(spdrv);
t1.setVisibility(View.GONE);
mylist = new ArrayList<HashMap<String, String>>();
pos = new ArrayList<String>();
Bundle bundle = getIntent().getExtras();
String stuff = bundle.getString("stuff");
Toast.makeText(getApplicationContext(), "Stuff= |" + stuff + "|",
Toast.LENGTH_LONG).show();
if (stuff.contains("null")) {
t1.setVisibility(View.VISIBLE);
t1.setText("No Records Found");
Toast.makeText(getApplicationContext(), "No Records Found!",
Toast.LENGTH_LONG).show();
} else {
load_list(stuff); //Load list with values
}
mCloseButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
flag = 1;
query = "Select make, model, version, expected_price, registration_place FROM `used_cars` where registration_place ="
+ "'" + j_reg_plc + "'";
if (cb1.isChecked()) {
query = query + " AND transmission ='Yes'";
}
if (cb2.isChecked()) {
query = query + " AND ac ='Yes'";
}
if (cb3.isChecked()) {
query = query + " AND car_lockk ='Yes'";
}
if (cb4.isChecked()) {
query = query + " AND sunroof ='Yes'";
}
if (cb5.isChecked()) {
query = query + " AND window ='Yes'";
}
if (cb6.isChecked()) {
query = query + " AND seats ='Yes'";
}
if (cb7.isChecked()) {
query = query + " AND stearing ='Yes'";
}
if (cb8.isChecked()) {
query = query + " AND player ='Yes'";
}
if (cb9.isChecked()) {
query = query + " AND sound_system ='Yes'";
}
if (cb10.isChecked()) {
query = query + " AND wheels ='Yes'";
}
query = query + ";";
Toast.makeText(getApplicationContext(), "QUERY= " + query,
Toast.LENGTH_LONG).show();
System.out.println("QUERY= " + query);
startDownload();
mDrawer.animateClose();
}
});
mOpenButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if (!mDrawer.isOpened())
mDrawer.animateOpen();
}
});
}
private void startDownload() {
new AppTask().execute(FILENAME);
}
public class AppTask extends AsyncTask<String, Integer, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
protected void onPostExecute(String result) {
super.onPostExecute(result);
Toast.makeText(getApplicationContext(), "res" + result,
Toast.LENGTH_LONG).show();
pos = new ArrayList<String>();
mylist.clear();
load_list(result); //Refresh list with new values
}
@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
}
@Override
protected String doInBackground(String... params) {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://animsinc.com/filter.php");
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(
5);
nameValuePairs.add(new BasicNameValuePair("Qry", query));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
httpclient.execute(httppost);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = EntityUtils.toString(entity);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
}
return is;
}
}
@Override
public void onContentChanged() {
super.onContentChanged();
mCloseButton = (Button) findViewById(R.id.button_close);
mOpenButton = (Button) findViewById(R.id.button_open);
mDrawer = (MultiDirectionSlidingDrawer) findViewById(R.id.drawer);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
@Override
public void onDrawerClosed() {
// TODO Auto-generated method stub
// demo.setVisibility(View.VISIBLE);
}
@Override
public void onDrawerOpened() {
// TODO Auto-generated method stub
// demo.setVisibility(View.GONE);
}
public void load_list(String lt) {
// list.setAdapter(null);
Toast.makeText(getApplicationContext(), "Inside load_list", 100).show();
try {
JSONArray jArray = new JSONArray(lt.toString());
for (int i = 0; i < jArray.length(); i++) {
Toast.makeText(getApplicationContext(),
"Inside load_list----FOR", 100).show();
map = new HashMap<String, String>();
JSONObject jObject = jArray.getJSONObject(i);
j_id = jObject.getString(ID);
j_make = jObject.getString(MAKE);
j_model = jObject.getString(MODEL);
j_version = jObject.getString(VERSION);
j_price = jObject.getString(PRICE);
j_reg_plc = jObject.getString(PLACE_REG);
data = j_make + "";
map.put("make", data);
data = j_model + "";
map.put("model", data);
data = j_version + "";
map.put("version", data);
data = j_price + "";
map.put("price", data);
data = j_reg_plc + "";
map.put("place", data);
mylist.add(map);
pos.add(j_id);
}
} catch (JSONException e) {
e.printStackTrace();
}
list = (ListView) findViewById(R.id.listView1);
String[] from = new String[] { "make", "model", "version", "price",
"place" };
int[] to = new int[] { R.id.text1, R.id.text5, R.id.text3, R.id.text4,
R.id.text2 };
adapter = new SimpleAdapter(this, mylist, R.layout.text_adaptr, from,
to);
Toast.makeText(getApplicationContext(), "B4 list setAdapter", 100)
.show();
// mylist.notifyDataSetChanged();
list.setAdapter(adapter);
// ---------------------------------
int[] colors = { 0, 0xff00ffff, 0 }; // red for the example
list.setDivider(new GradientDrawable(Orientation.RIGHT_LEFT, colors));
list.setDividerHeight(4);
list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
String data = pos.get(position) + "";
Toast.makeText(getApplicationContext(), "data: " + data,
Toast.LENGTH_LONG).show();
// Display_Car dc=new Display_Car();
// dc.get_cid(data);
Intent myIntent = new Intent(Slider.this, Buy_View.class);
Bundle bundle = new Bundle();
// Add your data to bundle
bundle.putString("stuff", data);
// Add the bundle to the intent
myIntent.putExtras(bundle);
startActivity(myIntent);
}
});
// ---------------------------------
}
}