【发布时间】：2017-09-30 10:45:55
【问题描述】：
我正在创建一个应在列表视图中显示景点的应用程序。 数据是从 json 解析的。 在这个 json 中有一个列，它声明了视线所在的城市。 现在我想创建一种过滤器，它应该使用我的 Json 中的 City 值检查当前的 Cityname。 例如，柏林有一个景点，我现在的城市是柏林，列表视图应该显示它。如果用户在慕尼黑并且视线在柏林，则列表视图不应显示此项目。 我从 TextView 中的不同 Activity 获取当前 cityname 值。 这是我的 Listview 活动：
public class Locations extends AppCompatActivity implements AdapterView.OnItemClickListener {
ArrayList<productforloc> arrayList;
ListView lv;
private String TAG = Locations.class.getSimpleName();
private TextView addressField; //Add a new TextView to your activity_main to display the address
private LocationManager locationManager;
private String provider;
int i = 1;
private ProgressDialog pDialog;
String name;
// URL to get contacts JSON
private static String url = "http://partypeople.bplaced.net/maptest.json";
ArrayList<HashMap<String, String>> contactList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.content_main);
Intent i = getIntent();
String cityname = i.getExtras().getString("cityname");
TextView city = (TextView) findViewById(R.id.ort);
city.setText(cityname);
pDialog = new ProgressDialog(Locations.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(true);
pDialog.show();
arrayList = new ArrayList<>();
lv = (ListView) findViewById(R.id.lv);
lv.setOnItemClickListener((AdapterView.OnItemClickListener) this);
runOnUiThread(new Runnable() {
@Override
public void run() {
new ReadJSON().execute(url);
}
});
final ImageButton filteropen = (ImageButton) findViewById(R.id.aufklaupen);
filteropen.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
RelativeLayout filter = (RelativeLayout) findViewById(R.id.filterloc);
filter.setVisibility(View.VISIBLE);
ImageButton filterclose = (ImageButton) findViewById(R.id.zuklappen);
filterclose.setVisibility(View.VISIBLE);
filteropen.setVisibility(View.INVISIBLE);
}
});
final ImageButton filterclose = (ImageButton) findViewById(R.id.zuklappen);
filterclose.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
RelativeLayout filter = (RelativeLayout) findViewById(R.id.filterloc);
filter.setVisibility(View.INVISIBLE);
ImageButton filteropen = (ImageButton) findViewById(R.id.aufklaupen);
filteropen.setVisibility(View.VISIBLE);
filterclose.setVisibility(View.INVISIBLE);
}
});
}
class ReadJSON extends AsyncTask<String,Integer,String> {
@Override
protected String doInBackground(String... params) {
return readURL(params[0]);
}
@Override
protected void onPostExecute(String content) {
try{
JSONObject jo = new JSONObject(content);
JSONArray ja = jo.getJSONArray("contacts");
for(int i=0;i<ja.length();i++){
JSONObject po = ja.getJSONObject(i);
arrayList.add(new productforloc(
po.getString("imageurl"),
po.getString("name"),
po.getString("street"),
po.getString("postalcode"),
po.getString("musicstyle"),
po.getString("musicsecond"),
po.getString("entry"),
po.getString("opening"),
po.getString("agegroup"),
po.getString("urlbtn"),
po.getString("Fsk"),
po.getString("city"),
po.getString("bg")
));
}
} catch (JSONException e) {
e.printStackTrace();
}
final CustomListAdapterforloc adapter = new CustomListAdapterforloc(getApplicationContext(),R.layout.model,arrayList);
lv.setAdapter(adapter);
if(pDialog.isShowing()){
pDialog.dismiss();
}
}
}
private String readURL(String url){
StringBuilder content = new StringBuilder();
try{
URL uri = new URL(url);
URLConnection urlConnection = uri.openConnection();
BufferedReader bufferedReader= new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
String line;
while((line = bufferedReader.readLine()) !=null){
content.append(line+"\n");
}
bufferedReader.close();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return content.toString();
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
productforloc pForloc = arrayList.get(position);
Intent intent = new Intent();
intent.setClass(this,DetailActivity.class);
intent.putExtra("name",pForloc.getName());
intent.putExtra("imageurl",pForloc.getImage());
intent.putExtra("street",pForloc.getStreet());
intent.putExtra("postalcode",pForloc.getPostalcode());
intent.putExtra("entry",pForloc.getEntry());
intent.putExtra("agegroup",pForloc.getAgegroup());
intent.putExtra("opening",pForloc.getOpening());
intent.putExtra("urlbtn",pForloc.getUrlbtn());
intent.putExtra("Fsk",pForloc.getFsk());
intent.putExtra("city",pForloc.getCity());
intent.putExtra("musicstyle",pForloc.getMusicstyle());
intent.putExtra("musicsecond",pForloc.getMusicsecond());
intent.putExtra("bg",pForloc.getBg());
startActivity(intent);
}
/**
* Async task class to get json by making HTTP call
}
*/
}
这是我的 Customlistadapter Activity；
public class CustomListAdapterforloc extends ArrayAdapter<productforloc>{
ArrayList<productforloc> products;
Context context;
int resource;
public CustomListAdapterforloc(Context context, int resource, List<productforloc> products) {
super(context, resource, products);
this.products = (ArrayList<productforloc>) products;
this.context = context;
this.resource = resource;
}
@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView== null){
LayoutInflater layoutInflater = (LayoutInflater) getContext().getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
convertView = layoutInflater.inflate(R.layout.model,null,true);
}
productforloc product = getItem(position);
ImageView imageView = (ImageView) convertView.findViewById(R.id.imagelist);
Picasso.with(context).load(product.getImage()).into(imageView);
TextView txtName= (TextView) convertView.findViewById(R.id.namelist);
txtName.setText(product.getName());
return convertView;
}
}
【问题讨论】：
-
你为什么不把你想要的项目保留在你的产品数组列表中？这不是你的解决方案吗？也可以在这行之前做，final CustomListAdapterforloc adapter = new CustomListAdapterforloc(getApplicationContext(),R.layout.model,arrayList);
-
是的，当然，这是我想做的，但我该怎么做
标签： android listview filtering