在应用程序中我正在从Url加载数据并在列表视图中显示它。我从Url检索的总项目是5项目，它在listview中成功显示。但是getView（）在后端运行无限次。 IT继续打电话直到活动还活着。我无法理解它为什么要打电话这么多时间。 我的代码是
public class asasa extends Activity {
//ListView listView;
Intent intent;
public int currentimageindex=0;
private ProgressDialog pDialog;
//Class Declartion DataHolder
DataHolder obj;
Timer timer;
TimerTask task;
ImageView slidingimage;
private int[] IMAGE_IDS = {
R.drawable.myno, R.drawable.cock, R.drawable.item,
R.drawable.ketchup,R.drawable.oil,R.drawable.pan
};
//ProgressDialog progressDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
static final String URL = "http://10.0.2.2/android_connect/get_all_products.php";
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_NAME = "name";
private static final String TAG_Description = "description";
private static final String TAG_URL = "url";
private static final String TAG_Price = "price";
LazyAdapter adapter;
// flag for Internet connection status
Boolean isInternetPresent = false;
// products JSONArray
JSONArray products = null;
// Connection detector class
ConnectionDetector cd;
String ITEMTITLE ="HasMapValue";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
cd = new ConnectionDetector(getApplicationContext());
// get Internet status
isInternetPresent = cd.isConnectingToInternet();
if (isInternetPresent) {
LoadAllProducts il = new LoadAllProducts();
il.execute(URL);
}
else
{
// Internet connection is not present
// Ask user to connect to Internet
Toast.makeText(asasa.this, "No Internet Connection You don't have internet connection.", Toast.LENGTH_LONG).show();
}
}
public void longToast(CharSequence message) {
Toast.makeText(this, message, Toast.LENGTH_LONG).show();
}
public class LazyAdapter extends BaseAdapter {
private Activity activity;
private LayoutInflater inflater=null;
private ArrayList<HashMap<String, Object>> data;
int i=0;
public LazyAdapter(Activity a, ArrayList<HashMap<String, Object>> d) {
activity = a;
data=d;
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public int getCount() {
return data.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
if(convertView==null)
vi = inflater.inflate(R.layout.list_row, null);
TextView title = (TextView)vi.findViewById(R.id.title); // title
TextView artist = (TextView)vi.findViewById(R.id.artist); // artist name
TextView duration = (TextView)vi.findViewById(R.id.duration); // duration
ImageView imageview=(ImageView) vi.findViewById(R.id.list_image);
HashMap<String, Object> song = new HashMap<String, Object>();
song = data.get(position);
DataHolder objj=new DataHolder();
objj=(DataHolder) song.get(ITEMTITLE);
Log.i("iiiiii "," " +i++);
Log.i("objj.GetName() ",objj.GetName());
Log.i("objj.GetDescription() ",objj.GetDescription());
Log.i("objj.GetPrice() ",objj.GetPrice());
title.setText(objj.GetName());
artist.setText(objj.GetDescription());
duration.setText(objj.GetPrice());
imageview.setImageBitmap(objj.Getimage());
return vi;
}
}
class LoadAllProducts extends AsyncTask<String, String, String> {
// creating new HashMap
ArrayList<HashMap<String, Object>> productsList=new ArrayList<HashMap<String,Object>>();
Bitmap decodedByte;
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(asasa.this);
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products 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, "GET", params);
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
Log.i("products ",products.toString());
// looping through All Products
Log.i("LENGTHHHH "," "+products.length());
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
Log.i("ccccccccc ",c.toString());
// Storing each json item in variable
// String id = c.getString(TAG_PID);
String name = c.getString(TAG_NAME);
Log.i("name::",name);
String description = c.getString(TAG_Description);
Log.i("description::",description);
String price = c.getString(TAG_Price);
Log.i("price",price);
byte[] decodedString = Base64.decode(c.getString(TAG_URL), Base64.DEFAULT);
decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
obj=new DataHolder();
obj.setData(name, description, price, decodedByte);
HashMap<String, Object> map = new HashMap<String, Object>();
map.put(ITEMTITLE, obj);
productsList.add(map);
}
} else {
// no products found
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
ListView list;
// dismiss the dialog after getting all products
list=(ListView)findViewById(R.id.list);
adapter=new LazyAdapter(asasa.this, productsList);
list.setAdapter(adapter);
// Click event for single list row
list.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
}
});
if (pDialog.isShowing()) {
pDialog.dismiss();
}
}
}
public void onPause()
{
super.onPause();
}
public class DataHolder
{
String Name;
String Description;
String Price;
Bitmap image;
public void setData(String Name,String Descipton,String Price,Bitmap iamage)
{
this.Name=Name;
this.Description=Descipton;
this.Price=Price;
this.image=iamage;
}
public String GetName()
{return Name;}
public String GetDescription()
{return Description;}
public String GetPrice()
{return Price;}
public Bitmap Getimage()
{return image;}
}
}
getview（）
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
if(convertView==null)
vi = inflater.inflate(R.layout.list_row, null);
TextView title = (TextView)vi.findViewById(R.id.title); // title
TextView artist = (TextView)vi.findViewById(R.id.artist); // artist name
TextView duration = (TextView)vi.findViewById(R.id.duration); // duration
ImageView imageview=(ImageView) vi.findViewById(R.id.list_image);
HashMap<String, Object> song = new HashMap<String, Object>();
song = data.get(position);
DataHolder objj=new DataHolder();
objj=(DataHolder) song.get(ITEMTITLE);
Log.i("iiiiii "," " +i++);
Log.i("objj.GetName() ",objj.GetName());
Log.i("objj.GetDescription() ",objj.GetDescription());
Log.i("objj.GetPrice() ",objj.GetPrice());
title.setText(objj.GetName());
artist.setText(objj.GetDescription());
duration.setText(objj.GetPrice());
imageview.setImageBitmap(objj.Getimage());
return vi;
}
XML
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/background" >
<include layout="@layout/footer" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="460dp"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:background="@drawable/background2"
android:minHeight="400dp"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="@drawable/bar" >
<Button
android:id="@+id/back"
android:layout_width="50dp"
android:layout_height="50dp"
android:background="@drawable/left" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<ImageView
android:id="@+id/ImageView3_Left"
android:layout_width="200dp"
android:layout_height="150dp"
android:layout_gravity="center_vertical|center_horizontal"
android:layout_marginTop="20dp" >
</ImageView>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="10dp"
android:background="@drawable/textarea"
android:orientation="vertical" >
<ListView
android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:divider="#b5b5b5"
android:dividerHeight="1dp"
android:listSelector="@drawable/list_selector" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
答案 0 :(得分：4)
我会在这里为其他人发布答案..
使用ListView时，请确保将固定高度设置为ListView，否则将多次调用getView()。这是因为ListView尝试计算可见的项目数。
答案 1 :(得分：0)
我相信我已经解决了这个问题。
BaseAdapter适配器要求listview具有与fill_parent或match_parent匹配的高关联