我想通过json的url解析数据和图像。
我使用以下代码来做同样的事情。但是当我向下滚动时，我不明白为什么图像会消失。
任何人都可以告诉我当我向下滚动时如何停止消失图像？
图像随机加载我该如何解决？
请在下面找到源代码链接： -
http://www.wingnity.com/blog/android-json-parsing-and-image-loading-tutorial/
公共类MainActivity扩展了Activity {
ArrayList<Actors> actorsList;
ActorAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
actorsList = new ArrayList<Actors>();
new JSONAsyncTask().execute("http://milagro.in/wip/apps/n/THDC2.json");
ListView listview = (ListView)findViewById(R.id.list);
adapter = new ActorAdapter(getApplicationContext(), R.layout.row, actorsList);
listview.setAdapter(adapter);
listview.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position,
long id) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), actorsList.get(position).gettata_project_name(), Toast.LENGTH_LONG).show();
}
});
}
class JSONAsyncTask extends AsyncTask<String, Void, Boolean> {
ProgressDialog dialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
dialog = new ProgressDialog(MainActivity.this);
dialog.setMessage("Loading, please wait");
dialog.setTitle("Connecting server");
dialog.show();
dialog.setCancelable(false);
}
@Override
protected Boolean doInBackground(String... urls) {
try {
//------------------>>
HttpGet httppost = new HttpGet(urls[0]);
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(httppost);
// StatusLine stat = response.getStatusLine();
int status = response.getStatusLine().getStatusCode();
if (status == 200) {
HttpEntity entity = response.getEntity();
String data = EntityUtils.toString(entity);
JSONObject jsono = new JSONObject(data);
JSONArray jarray = jsono.getJSONArray("data");
for (int i = 0; i < jarray.length(); i++) {
JSONObject object = jarray.getJSONObject(i);
Actors actor = new Actors();
actor.settata_project_name(object.getString("tata_project_name"));
actor.setproject_Typology(object.getString("project_Typology"));
actor.setproject_logo_url(object.getString("project_logo_url"));
actor.setprice(object.getString("price"));
actorsList.add(actor);
}
return true;
}
//------------------>>
} catch (ParseException e1) {
e1.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return false;
}
protected void onPostExecute(Boolean result) {
dialog.cancel();
adapter.notifyDataSetChanged();
if(result == false)
Toast.makeText(getApplicationContext(), "Unable to fetch data from server", Toast.LENGTH_LONG).show();
}
}
}
public class ActorAdapter extends ArrayAdapter<Actors> {
ArrayList<Actors> actorList;
LayoutInflater vi;
int Resource;
ViewHolder holder;
public ActorAdapter(Context context, int resource, ArrayList<Actors> objects) {
super(context, resource, objects);
vi = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
Resource = resource;
actorList = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// convert view = design
View v = convertView;
if (v == null) {
holder = new ViewHolder();
v = vi.inflate(Resource, null);
holder.imageview = (ImageView) v.findViewById(R.id.ivImage);
holder.Projectname = (TextView) v.findViewById(R.id.Projectname);
holder.typology = (TextView) v.findViewById(R.id.typology);
holder.price = (TextView) v.findViewById(R.id.price);
v.setTag(holder);
} else {
holder = (ViewHolder) v.getTag();
}
new DownloadImageTask(holder.imageview).execute(actorList.get(position).getproject_logo_url());
holder.imageview.setImageResource(R.drawable.ic_launcher);
//new DownloadImageTask(holder.imageview).execute(actorList.get(position).getproject_logo_url());
holder.Projectname.setText(actorList.get(position).gettata_project_name());
holder.typology.setText(actorList.get(position).getproject_Typology());
holder.price.setText("Price: " + actorList.get(position).getprice());
return v;
}
static class ViewHolder {
public ImageView imageview;
public TextView Projectname;
public TextView typology;
public TextView price;
}
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
公共类演员{
private String tata_project_name;
private String project_Typology;
private String project_logo_url;
private String price;
public Actors() {
// TODO Auto-generated constructor stub
}
public Actors(String tata_project_name, String project_Typology,String project_logo_url, String price ) {
super();
this.tata_project_name = tata_project_name;
this.project_Typology = project_Typology;
this.project_logo_url = project_logo_url;
this.price = price;
}
public String gettata_project_name() {
return tata_project_name;
}
public void settata_project_name(String tata_project_name) {
this.tata_project_name = tata_project_name;
}
public String getproject_Typology() {
return project_Typology;
}
public void setproject_Typology(String project_Typology) {
this.project_Typology = project_Typology;
}
public String getproject_logo_url() {
return project_logo_url;
}
public void setproject_logo_url(String project_logo_url) {
this.project_logo_url = project_logo_url;
}
public String getprice() {
return price;
}
public void setprice(String price) {
this.price = price;
}
}