Question

I have to develop an android view such that i have 2 spinner controls in it, one for state and the second for cities.

My question is, how can I populate the city spinner automatically whenever a state is selected?

What’s the logic behind it?

My 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>

My 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>

And my activity.java file:

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

Here is the correct way dear….

I had wrote all the needed states and cities in string_arays….

like

<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

then in main xml added 2 spinners for both. i belive all of u can do i simple, na?

then i have my main.xml as…

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);
        }

Just check a look and do it by yourself…
Hope this will helps u a little…

k dear friends..
Sujith