我试图根据第一个spinner中的选择来获取第二个微调器中的状态。如果我选择印度获得所有状态但我不想那样，我只需要印度国家，请帮助我。我粘贴了我的代码
package com.example.sankar.machinetest;
import android.content.res.AssetManager;
import android.content.res.Resources;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemClickListener, AdapterView.OnItemSelectedListener {
private Spinner countrySpinner, stateSpinner, citySpinner;
private TextView cityCodeTextView;
private Button submitButton;
private ArrayList<String> country_list, state_list, city_list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
countrySpinner = (Spinner) findViewById(R.id.county);
stateSpinner = (Spinner) findViewById(R.id.states);
citySpinner = (Spinner) findViewById(R.id.city);
country_list = new ArrayList<String>();
state_list = new ArrayList<String>();
city_list = new ArrayList<String>();
try {
JSONObject jsonObject = new JSONObject(loadJsonFromAsset());
JSONArray jsonArray = jsonObject.getJSONArray("countries");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject countries_object = jsonArray.getJSONObject(i);
String country_name = countries_object.getString("name");
String country_code = countries_object.getString("countryCode");
country_list.add(country_name);
JSONArray states_array = countries_object.getJSONArray("states");
for (int j = 0; j < states_array.length(); j++) {
JSONObject states_object = states_array.getJSONObject(j);
String state_name = states_object.getString("name");
state_list.add(state_name);
JSONArray city_array = states_object.getJSONArray("cities");
for (int k = 0; k < city_array.length(); k++) {
JSONObject city_object = city_array.getJSONObject(k);
String city_name = city_object.getString("name");
String city_code = city_object.getString("code");
city_list.add(city_name);
}
}
}
ArrayAdapter<String> country_adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_spinner_dropdown_item, country_list);
countrySpinner.setAdapter(country_adapter);
ArrayAdapter<String> city_adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_spinner_dropdown_item, city_list);
citySpinner.setAdapter(city_adapter);
countrySpinner.setOnItemSelectedListener(this);
} catch (JSONException e) {
e.printStackTrace();
}
}
public String loadJsonFromAsset() {
String json = null;
try {
InputStream is = getAssets().open("countries.json");
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
json = new String(buffer, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return json;
}
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
}
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int position, long l) {
if (position==0) {
ArrayAdapter<String> state_adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_spinner_dropdown_item, state_list);
stateSpinner.setAdapter(state_adapter);
}
}
@Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
}
我的json是
{
"countries": [{
"name": "India",
"countryCode": "91",
"states": [{
"name": "Kerala",
"cities": [{
"name": "Thrissur",
"code": "680111"
}, {
"name": "Kochi",
"code": "680222"
}, {
"name": "Trivandrum",
"code": "680333"
}]
}, {
"name": "TamilNadu",
"cities": [{
"name": "Chennai",
"code": "380111"
}, {
"name": "Coimbatore",
"code": "380222"
}]
}]
}, {
"name": "Germany",
"countryCode": "49",
"states": [{
"name": "Bayern",
"cities": [{
"name": "Nurnburg",
"code": "123"
}, {
"name": "Munich",
"code": "125"
}]
}, {
"name": "Berlin",
"cities": [{
"name": "Berlin",
"code": "223"
}]
}]
}]
}
答案 0 :(得分：1)
你可以试试这个
public class Country {
private String name;
private String code;
private List<State> states;
public Country(String name, String code, List<State> states) {
this.name = name;
this.code = code;
this.states = states;
}
public String getName() {
return name;
}
public String getCode() {
return code;
}
public List<State> getStates() {
return states;
}
@Override
public String toString() {
return name;
}
}
public class State {
private String name;
private List<City> cities;
public State(String name, List<City> cities) {
this.name = name;
this.cities = cities;
}
public String getName() {
return name;
}
public List<City> getCities() {
return cities;
}
@Override
public String toString() {
return name;
}
}
public class City {
private String name;
private String code;
public City(String name, String code) {
this.name = name;
this.code = code;
}
public String getName() {
return name;
}
public String getCode() {
return code;
}
@Override
public String toString() {
return name;
}
}
然后像这样
从JSON构建数据try {
JSONObject jsonObject = new JSONObject(loadJsonFromAsset());
JSONArray jsonArray = jsonObject.getJSONArray("countries");
List<Country> countries;
List<City> cities;
List<State> states;
countries = new ArrayList<>();
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject countries_object = jsonArray.getJSONObject(i);
// get country name and code
String country_name = countries_object.getString("name");
String country_code = countries_object.getString("countryCode");
// get country states
JSONArray states_array = countries_object.getJSONArray("states");
states = new ArrayList<>();
for (int j = 0; j < states_array.length(); j++) {
JSONObject states_object = states_array.getJSONObject(j);
// get state name
String state_name = states_object.getString("name");
// get all city for this state
JSONArray city_array = states_object.getJSONArray("cities");
cities = new ArrayList<>();
for (int k = 0; k < city_array.length(); k++) {
JSONObject city_object = city_array.getJSONObject(k);
// get city name and code
String city_name = city_object.getString("name");
String city_code = city_object.getString("code");
// add new city
cities.add(new City(city_name, city_code));
}
// add new state with cities
states.add(new State(state_name, cities));
}
countries.add(new Country(country_name, country_code, states));
}
ArrayAdapter<Country> country_adapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_dropdown_item, countries);
country_adapter.setAdapter(mCountryAdapter);
country_adapter.setOnItemSelectedListener(this);
} catch (JSONException e) {
e.printStackTrace();
}
最后
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
Country country = (Country) mCountrySpinner.getSelectedItem();
mStateSpinner.setAdapter(new ArrayAdapter<>(this, android.R.layout.simple_spinner_dropdown_item, country.getStates()));
}
答案 1 :(得分：0)
String countryCode = null;
You can call your second spinner in onItemSelected method.
countryCode = countrySpinner.getSelectedItem().toString();
// call your second adapter
before populate state list
HashMap<String, String> hmap = new HashMap<String, String>();
hmap.put(country_code, stateName);