SideBar 选择城市时右侧边上的 选择bar

        需要定义一个SideBar的视图类  在布局文件中引用   同时在布局中设置一个textView默认不可见 

当触摸时才显示   在调用的Activity中 

sideBar.setOnTouchingLetterChangedListener方法
离开时不可见   同时联动listView  listView.setSelection(i)设置联动;

package com.archie.lazyhousewifery.cityandauntdetail.makeview;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TextView;

import com.archie.lazyhousewifery.cityandauntdetail.Constants;

public class SideBar extends View {

    public String[] characters = new String[] { "#", "A", "B", "C", "D", "E", "F",
            "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W",
            "X", "Y", "Z" };

    private Paint paint;
    private int textSize = 16;
    private int defaultTextColor = Color.parseColor("#D2D2D2");
    private int selectedTextColor = Color.parseColor("#2DB7E1");
    private int touchedBgColor = Color.parseColor("#F5F5F5");
    private TextView  text_dialog;

    private OnTouchingLetterChangedListener onTouchingLetterChangedListener;

    private int position = -1;

    public SideBar(Context context) {
        super(context);
    }

    public SideBar(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public SideBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }
    
    public void setTextDialog(TextView textView){
        this.text_dialog = textView;
    } 

    private void init() {
        paint = new Paint();
        paint.setAntiAlias(true);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        int height = getHeight();
        int width = getWidth();
        int singleHeight = height / characters.length;

        for (int i = 0; i < characters.length; i++) {
            if (i == position) {
                paint.setColor(selectedTextColor);
            } else {
                paint.setColor(defaultTextColor);
            }
            paint.setTextSize(textSize);

            float xPos = width / 2 - paint.measureText(characters[i]) / 2;
            float yPos = singleHeight * i + singleHeight;
            canvas.drawText(characters[i], xPos, yPos, paint);
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int action = event.getAction();
        float y = event.getY();
        position = (int) (y / (getHeight() / characters.length));
        if (position >= 0 && position < Constants.CITY_TYPE.length) {
            onTouchingLetterChangedListener.onTouchingLetterChanged(position);
            switch (action) {
                case MotionEvent.ACTION_UP:
                    setBackgroundColor(Color.TRANSPARENT);
                    position = -1;
                    invalidate();
                    if (text_dialog != null) {
                        text_dialog.setVisibility(View.INVISIBLE);
                    }
                    break;
                default:
                    setBackgroundColor(touchedBgColor);
                    invalidate();
                    text_dialog.setText(characters[position]);
                    break;
            }
        }else{

            setBackgroundColor(Color.TRANSPARENT);
            if (text_dialog != null) {
                text_dialog.setVisibility(View.INVISIBLE);
            }

        }
        return true;
    }

    public void setOnTouchingLetterChangedListener(
            OnTouchingLetterChangedListener onTouchingLetterChangedListener) {
        this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;
    }


    public interface OnTouchingLetterChangedListener {
        public void onTouchingLetterChanged(int position);
    }

}

private void initSideBar() {

        sideBar.setTextDialog(dialog_text);
        sideBar.setOnTouchingLetterChangedListener(new SideBar.OnTouchingLetterChangedListener() {

            @Override
            public void onTouchingLetterChanged(int position) {
                String city_label = Constants.CITY_TYPE[position];
                for (int i = 0; i < cityList.size(); i++) {
                    if (cityList.get(i).getCityName().equals(city_label)) {

                        cityListView.setSelection(i);
                        dialog_text.setVisibility(View.VISIBLE);
                        break;
                    }
                    if(i == cityList.size() -1){

                        dialog_text.setVisibility(View.INVISIBLE);

                    }
                }
            }
        });

    }

上边的代码是在activity中引用sideBar  回调的方法  其他的稍作处理就可以运行了