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);
     }

 }

SideBar

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