WheelView运用实例，实现安卓仿苹果地址联动滑动选择

【核心代码】

package kankan.wheel.demo;

import com.example.wheeldemo.R;

import kankan.wheel.widget.OnWheelChangedListener;
import kankan.wheel.widget.OnWheelScrollListener;
import kankan.wheel.widget.WheelView;
import kankan.wheel.widget.adapters.AbstractWheelTextAdapter;
import kankan.wheel.widget.adapters.ArrayWheelAdapter;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

public class CitiesActivity extends Activity {
    // Scrolling flag
    private boolean scrolling = false;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.cities_layout);
                
        final WheelView country = (WheelView) findViewById(R.id.country);
        country.setVisibleItems(3);
        country.setViewAdapter(new CountryAdapter(this));

        final String cities[][] = new String[][] {
                new String[] {"New York", "Washington", "Chicago", "Atlanta", "Orlando"},
                new String[] {"Ottawa", "Vancouver", "Toronto", "Windsor", "Montreal"},
                new String[] {"Kiev", "Dnipro", "Lviv", "Kharkiv"},
                new String[] {"Paris", "Bordeaux"},
                };
        
        final WheelView city = (WheelView) findViewById(R.id.city);
        city.setVisibleItems(5);

        country.addChangingListener(new OnWheelChangedListener() {
            public void onChanged(WheelView wheel, int oldValue, int newValue) {
                if (!scrolling) {
                    updateCities(city, cities, newValue);
                }
            }
        });
        
        country.addScrollingListener( new OnWheelScrollListener() {
            public void onScrollingStarted(WheelView wheel) {
                scrolling = true;
            }
            public void onScrollingFinished(WheelView wheel) {
                scrolling = false;
                updateCities(city, cities, country.getCurrentItem());
            }
        });

        country.setCurrentItem(1);
    }
    
    /**
     * Updates the city wheel
     */
    private void updateCities(WheelView city, String cities[][], int index) {
        ArrayWheelAdapter<String> adapter =
            new ArrayWheelAdapter<String>(this, cities[index]);
        adapter.setTextSize(18);
        city.setViewAdapter(adapter);
        city.setCurrentItem(cities[index].length / 2);  
        TextView select_city = (TextView) findViewById(R.id.select_city);
        select_city.setText(cities[index][getWheel(R.id.city).getCurrentItem()]);
    }
    
    private WheelView getWheel(int id) {
        return (WheelView) findViewById(id);
    }

    /**
     * Adapter for countries
     */
    private class CountryAdapter extends AbstractWheelTextAdapter {
        // Countries names
        private String countries[] =
            new String[] {"USA", "Canada", "Ukraine", "France"};
        // Countries flags
        private int flags[] =
            new int[] {R.drawable.usa, R.drawable.canada, R.drawable.ukraine, R.drawable.france};
        
        /**
         * Constructor
         */
        protected CountryAdapter(Context context) {
            super(context, R.layout.country_layout, NO_RESOURCE);
            
            setItemTextResource(R.id.country_name);
        }

        @Override
        public View getItem(int index, View cachedView, ViewGroup parent) {
            View view = super.getItem(index, cachedView, parent);
            ImageView img = (ImageView) view.findViewById(R.id.flag);
            img.setImageResource(flags[index]);
            return view;
        }
        
        @Override
        public int getItemsCount() {
            return countries.length;
        }
        
        @Override
        protected CharSequence getItemText(int index) {
            return countries[index];
        }
    }
}