滚轮控件的定义和使用

package com.ct.mywheel;

import wheel.OnWheelChangedListener;
import wheel.OnWheelScrollListener;
import wheel.WheelView;
import wheeladapter.AbstractWheelTextAdapter;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MainActivity extends Activity {
    private LinearLayout categaryLayout;
    private ImageView categaryImg;
    private TextView categaryTv;
    private String[] expense_explanation;
    private Integer[] expense_images;
    private Integer expenses_id=0,account_id=0;
    private boolean scrolling = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main); 
        categaryLayout = (LinearLayout)findViewById(R.id.expense_category);
        categaryImg = (ImageView)findViewById(R.id.expense_category_imv);
        categaryTv = (TextView)findViewById(R.id.expense_category_tv); 
        expense_explanation = getResources().getStringArray(R.array.EXPENSES_CATEGORY);
        expense_images = new Integer[]{R.drawable.repast, R.drawable.xiuxianyule,
                R.drawable.book, R.drawable.shsj, R.drawable.juhuijiaoyou,
                R.drawable.liwu, R.drawable.huafeiwangfei, R.drawable.transport,
                R.drawable.cloth, R.drawable.touzikuisun, R.drawable.yiyao,
                R.drawable.other};
        categaryLayout.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
                builder.setTitle("选择支出种类");
                LayoutInflater inflater = LayoutInflater.from(MainActivity.this);
                View view = inflater.inflate(R.layout.expense_category_wheel, null);
                final WheelView expenses_category_wheel = (WheelView) view
                        .findViewById(R.id.expense_category_wheel);
                expenses_category_wheel.setVisibility(3);
                expenses_category_wheel.setViewAdapter(new MyExpensesAdapter(MainActivity.this,
                        expense_explanation, expense_images));
                
                expenses_category_wheel.addChangingListener(new OnWheelChangedListener() {
                    
                    @Override
                    public void onChanged(WheelView wheel, int oldValue, int newValue) {
                        // TODO Auto-generated method stub
                        expenses_id = newValue;
                    }
                });
                
                expenses_category_wheel.addScrollingListener(new OnWheelScrollListener() {
                    
                    @Override
                    public void onScrollingStarted(WheelView wheel) {
                        // TODO Auto-generated method stub
                        scrolling = true;
                    }
                    
                    @Override
                    public void onScrollingFinished(WheelView wheel) {
                        // TODO Auto-generated method stub
                         scrolling = false;
                         expenses_id=expenses_category_wheel.getCurrentItem();
                    }
                });
                builder.setView(view);
                builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        categaryImg.setImageResource(expense_images[expenses_id]);
                        categaryTv.setText(expense_explanation[expenses_id]);
                    }
                }).setNegativeButton("取消", null).create().show();
                
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
    private class MyExpensesAdapter extends AbstractWheelTextAdapter{
        
        private String[] explanation=null;
        private Integer[] images=null;
        
        
        
        @Override
        public View getItem(int index, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            View view = super.getItem(index, convertView, parent);
             ImageView img = (ImageView) view.findViewById(R.id.category);
             img.setImageResource(images[index]);
             TextView tv=(TextView) view.findViewById(R.id.expense_name);
             tv.setText(explanation[index]);
            return super.getItem(index, convertView, parent);
        }

        public MyExpensesAdapter(Context context,String[] explanation,Integer[] images) {
            super(context,R.layout.expense_category_wheel_item);
            this.explanation=explanation;
            this.images=images;
        }
        
        protected MyExpensesAdapter(Context context) {
            super(context);
            // TODO Auto-generated constructor stub
        }

        @Override
        public int getItemsCount() {
            // TODO Auto-generated method stub
            return explanation.length;
        }

        @Override
        protected CharSequence getItemText(int index) {
            // TODO Auto-generated method stub
            return explanation[index];
        }
        
    }
    
    

}

（在F:\java\MyWheel）