(dinámico) Múltiples hilanderos estado/ciudad

Question

Tengo que desarrollar una vista de Android que tenga 2 controles giratorios, uno para el estado y el segundo para las ciudades.

Mi pregunta es, ¿cómo puedo poblar el girador de ciudad automáticamente cada vez que se selecciona un estado?

¿Cuál es la lógica detrás de esto?

Mi string.xml:

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
<string name="spinner_category"></string> 
<string-array name="category_state"> 
    <item >kerala</item> 
    <item >tamil nadu</item> 
    <item >Andra Pradesh</item> 
    <item >karnataka</item> 
</string-array> 
</resources> 

Mi main.xml:

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical"> 

    <LinearLayout android:orientation="horizontal" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content"> 
     <TextView android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:padding="10dip" 
      android:text="Select : "/> 
     <Spinner android:layout_width="250dip" 
      android:layout_height="wrap_content" 
      android:id="@+id/spinner_state"/> 
    </LinearLayout> 

<LinearLayout android:orientation="horizontal" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content"> 
     <TextView android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:padding="10dip" 
      android:text="Select : "/> 
     <Spinner android:layout_width="250dip" 
      android:layout_height="wrap_content" 
      android:id="@+id/spinner_state"/> 
    </LinearLayout> 
</LinearLayout> 

Y mi archivo activity.java:

package com.converter; 

import android.app.Activity; 
import android.os.Bundle; 
import android.widget.ArrayAdapter; 
import android.widget.Spinner; 

public class ConverterActivity extends Activity 
{ 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     Spinner spinner_s = (Spinner)findViewById(R.id.spinner_state); 
     ArrayAdapter<CharSequence> category_adapter = ArrayAdapter.createFromResource(
       this, R.array.category_array, android.R.layout.simple_spinner_item); 
     category_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
     spinner_s.setAdapter(category_adapter); 

    } 
} 

Answer 1

Aquí es la forma correcta querida ....

que había escrito todos los estados y ciudades se necesitan en string_arays ....

como

<string-array name="State_array"> 
      <item >s1</item> 
      <item >s2</item> 
      <item >s3</item> 
      <item >s4</item> 
    </string-array> 
//then cities array for each states, like 
<string-array name="State1Cities_array"> 
      <item >c11</item> 
      <item >c12</item> 
      <item >c15</item> 
      <item >c13</item> 
    </string-array> 
<string-array name="State2Cities_array"> 
      <item >c1</item> 
      <item >c2</item> 
      <item >c5</item> 
      <item >c3</item> 
    </string-array> 

// and so on for all the states 

después en XML principal agregado 2 hilanderos para ambos. creo en todo lo que puedes hacer yo simple, na?

entonces tengo mi main.xml como ...

spinner_states_activity = (Spinner)findViewById(R.id.spinner_states_main); 
     spinner_states_activity.setOnItemSelectedListener(this); 
     adapter = ArrayAdapter.createFromResource(
       this, R.array.state_array, android.R.layout.simple_spinner_item); 
     adapter.setDropDownViewResource(R.layout.myspinner); 
// my layout for spinners u can use urs or defalut. k? 
     spinner_states_activity.setAdapter(adapter); 

spinner_cities_activity = (Spinner)findViewById(R.id.spinner_cities_main); 
     spinner_cities_activity.setOnItemSelectedListener(this); 

//and in function onItemSelected 

     int pos,pos2; 
     pos = spinner_states_activity.getSelectedItemPosition(); 
     int iden=parent.getId(); 
     if(iden==R.id.spinner_states_main) 
     { 
      pos2 = 0; 
      switch (pos) 
      { 
       case 0: unit_adapter= ArrayAdapter.createFromResource(
          this, R.array.States1Cities_array, android.R.layout.simple_spinner_item); 
         break; 
       case 1: unit_adapter= ArrayAdapter.createFromResource(
          this, R.array.States3Cities_array, android.R.layout.simple_spinner_item); 
         break; 
         // all the StatesxCities entires.... 
       default: 
         break; 
      } 

      spinner_cities_activity.setAdapter(unit_adapter); 
      unit_adapter.setDropDownViewResource(R.layout.myspinner); 
     } 

Sólo echa un vistazo y hacerlo por ti mismo ... Esperamos que esto ayuda u un poco ...

k queridos amigos .. Sujith

Answer 2

que tiene que hacer el paso folloowing

1. crear una fuente de datos de ciudades (ya sea base de datos o en hashmap ("estado", "ciudad")).

2. establece setOnItemSelectedListener (listener) para los estados que contienen spinner.

3. onItemSelected() método del listner anterior obtener los datos de datasouce creado en el primer paso y adjuntarlo a city spinner.

eso es todo.

Answer 3

public class ConverterActivity extends Activity { 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     Spinner citySpinner = (Spinner)findViewById(R.id.spinner_city); 
     final ArrayAdapter<String> cityAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, new String[]); // starts empty 
     city_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
     spinner_city.setAdapter(city_adapter); 

     Spinner categorySpinner = (Spinner)findViewById(R.id.spinner_state); 
     final ArrayAdapter<String> categoryAdapter = ArrayAdapter.createFromResource(
       this, R.array.category_array, android.R.layout.simple_spinner_item); 
     categoryAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
     categorySpinner.setAdapter(category_adapter); 
     categorySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { 
      @Override 
      public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { 
       String selectedState = parent.getItemAtPosition(position); 
       cityAdapter.clear(); // remove previous entries 
       // look up your cities for the state selectedState, using your own method 
       cityAdapter.add(the cities you want); // do that in a loop for all your cities 
       cityAdapter.notifyDataSetChanged(); 
      }; 
      @Override 
      public void onNothingSelected(AdapterView<?> parent) { 
       // do nothing 
      } 
     }); 
    } 
} 

NB: codificado en el editor de stackoverflow, puede haber algunos errores de sintaxis :)

para buscar las ciudades de cada estado, utilizar cualquier método que desea: puede definir en múltiples cuerdas-array recursos, o las obtenga de una base de datos, etc.

Answer 4

Ejemplo:

Spinner city=(Spinner)findViewById(R.id.citySpinner); 
    Spinner state=(Spinner)findViewById(R.id.stateSpinner); 

    final ArrayList<String> state_options=new ArrayList<String>(); 
    final ArrayList<String> city_options=new ArrayList<String>(); 

    state_options.add("state_1"); 
    state_options.add("state_2"); 
    state_options.add("state_3"); 
    // Here you can also get a cursor and add Strings as options to state_options instead of what i have done 

    city_options.add("city_1_state_1"); 
    city_options.add("city_2_state_1"); 
    city_options.add("city_3_state_1"); 
    // Here you can also get a cursor and add Strings as options to city_options instead of what i have done 

    ArrayAdapter<String> cityAdapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_spinner_item,city_options); 
    city.setAdapter(cityAdapter); 

    ArrayAdapter<String> stateAdapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_spinner_item,state_options); 
    state.setAdapter(stateAdapter); 

    state.setOnItemSelectedListener(new OnItemSelectedListener() { 

     @Override 
     public void onItemSelected(AdapterView<?> arg0, View view, 
         int position, long id) { 

      String stateName=state_options.get(position).toString(); 
       resetCity(stateName);        
     } 

     @Override 
     public void onNothingSelected(AdapterView<?> arg0) { 

     } 
    }); 

Ahora,

public void resetCity(String stateName) 
{  
     city_options.removeAll(city_options);//i haven't checked this. 
     if(stateName.eqauls("state_1")) 
     { 
      city_option.add("city_1_state_1"); 
      city_options.add("city_2_state_1"); 
      city_options.add("city_3_state_1"); 
      //you can also get a cursor and add Strings as options to city_options instead of what i have done 
     } 
     else if(stateName.eqauls("state_2")) 
     { 
      city_option.add("city_1_state_2"); 
      city_options.add("city_2_state_2"); 
      city_options.add("city_3_state_2"); 
      // you can also get a cursor and add Strings as options to city_options instead of what i have done 
     } 
     else 
     { 
      city_option.add("city_1_state_3"); 
      city_options.add("city_2_state_3"); 
      city_options.add("city_3_state_3"); 
      //you can also get a cursor and add Strings as options to city_options instead of what i have done 
     } 

     ArrayAdapter<String> cityAdapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_spinner_item,city_options); 
     city.setAdapter(cityAdapter); 
} 

Este es el ejemplo más simple. Puede establecer su city_options y state_options desde su base de datos.y luego puede usarlo para rellenar hilanderos.