package com.example.circleprogressbar;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.RectF;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
public class RoundProgressBar extends View {
	
	
    public RoundProgressBar(Context context) {  
        this(context, null);  
    }  
  
    public RoundProgressBar(Context context, AttributeSet attrs) {  
        this(context, attrs, 0);  
    }  
      
    public RoundProgressBar(Context context, AttributeSet attrs, int defStyle) {  
        super(context, attrs, defStyle);  
          
        paint = new Paint();  
  
          
        TypedArray mTypedArray = context.obtainStyledAttributes(attrs,  
                R.styleable.RoundProgressBar);  
          
        //获取自定义属性和默认值  
        roundColor = mTypedArray.getColor(R.styleable.RoundProgressBar_roundColor, Color.RED);  
        roundProgressColor = mTypedArray.getColor(R.styleable.RoundProgressBar_roundProgressColor, Color.GREEN);  
        textColor = mTypedArray.getColor(R.styleable.RoundProgressBar_textColor, Color.GREEN);  
        textSize = mTypedArray.getDimension(R.styleable.RoundProgressBar_textSize, 15);  
        roundWidth = mTypedArray.getDimension(R.styleable.RoundProgressBar_roundWidth, 5);  
        max = mTypedArray.getInteger(R.styleable.RoundProgressBar_max, 100);  
        textIsDisplayable = mTypedArray.getBoolean(R.styleable.RoundProgressBar_textIsDisplayable, true);  
        style = mTypedArray.getInt(R.styleable.RoundProgressBar_style, 0);  
          
        mTypedArray.recycle();  
    }  
	/** 
     * 画笔对象的引用 
     */  
    private Paint paint;  
      
    /** 
     * 圆环的颜色 
     */  
    private int roundColor;  
      
    /** 
     * 圆环进度的颜色 
     */  
    private int roundProgressColor;  
      
    /** 
     * 中间进度百分比的字符串的颜色 
     */  
    private int textColor;  
      
    /** 
     * 中间进度百分比的字符串的字体 
     */  
    private float textSize;  
      
    /** 
     * 圆环的宽度 
     */  
    private float roundWidth;  
      
    /** 
     * 最大进度 
     */  
    private int max;  
      
    /** 
     * 当前进度 
     */  
    private int progress;  
    /** 
     * 是否显示中间的进度 
     */  
    private boolean textIsDisplayable;  
      
    /** 
     * 进度的风格,实心或者空心 
     */  
    private int style;  
      
    public static final int STROKE = 0;  
    public static final int FILL = 1;  
      
      
  
    @Override  
    protected void onDraw(Canvas canvas) {  
        super.onDraw(canvas);  
          
        /** 
         * 画最外层的大圆环 
         */  
        int centre = getWidth()/2; //获取圆心的x坐标  
        int radius = (int) (centre - roundWidth/2); //圆环的半径  
        paint.setColor(roundColor); //设置圆环的颜色  
        paint.setStyle(Paint.Style.STROKE); //设置空心  
        paint.setStrokeWidth(roundWidth); //设置圆环的宽度  
        paint.setAntiAlias(true);  //消除锯齿   
        canvas.drawCircle(centre, centre, radius, paint); //画出圆环  
          
        canvas.drawCircle(centre, centre, radius-20, paint);
        Log.e("log", centre + "");  
          
        /** 
         * 画进度百分比 
         */  
        paint.setStrokeWidth(0);   
        paint.setColor(textColor);  
        paint.setTextSize(textSize);  
        paint.setTypeface(Typeface.DEFAULT_BOLD); //设置字体  
        int percent = (int)(((float)progress / (float)max) * 100);  //中间的进度百分比,先转换成float在进行除法运算,不然都为0  
        float textWidth = paint.measureText(percent + "%");   //测量字体宽度,我们需要根据字体的宽度设置在圆环中间  
          
        if(textIsDisplayable && percent != 0 && style == STROKE){  
            canvas.drawText(percent + "%", centre - textWidth / 2, centre + textSize/2, paint); //画出进度百分比  
        }  
          
          
        /** 
         * 画圆弧 ,画圆环的进度 
         */  
          
        //设置进度是实心还是空心  
        paint.setStrokeWidth(roundWidth); //设置圆环的宽度  
        paint.setColor(roundProgressColor);  //设置进度的颜色  
        RectF oval = new RectF(centre - radius, centre - radius, centre  
                + radius, centre + radius);  //用于定义的圆弧的形状和大小的界限  
          
        switch (style) {  
        case STROKE:{  
            paint.setStyle(Paint.Style.STROKE);  
            canvas.drawArc(oval, 270, 360 * progress / max, false, paint);  //根据进度画圆弧  
            
             int pointY=(int) Math.sin(2*Math.PI/360*((360*progress / max+270)%360))*radius+centre;
             int pointx=(int) Math.cos(2*Math.PI/360*((360*progress / max+270)%360))*radius+centre;
             
             paint.setStyle(Style.FILL);
             paint.setStrokeWidth(1);
             canvas.drawCircle(pointx, pointY, roundWidth/2, paint);
            
            break;  
        }  
        case FILL:{  
            paint.setStyle(Paint.Style.FILL_AND_STROKE);  
            if(progress !=0)  
                canvas.drawArc(oval, 180, 360 * progress / max, true, paint);  //根据进度画圆弧  
            break;  
        }  
        }  
          
    }  
      
      
    public synchronized int getMax() {  
        return max;  
    }  
  
    /** 
     * 设置进度的最大值 
     * @param max 
     */  
    public synchronized void setMax(int max) {  
        if(max < 0){  
            throw new IllegalArgumentException("max not less than 0");  
        }  
        this.max = max;  
    }  
  
    /** 
     * 获取进度.需要同步 
     * @return 
     */  
    public synchronized int getProgress() {  
        return progress;  
    }  
  
    /** 
     * 设置进度,此为线程安全控件,由于考虑多线的问题,需要同步 
     * 刷新界面调用postInvalidate()能在非UI线程刷新 
     * @param progress 
     */  
    public synchronized void setProgress(int progress) {  
        if(progress < 0){  
            throw new IllegalArgumentException("progress not less than 0");  
        }  
        if(progress > max){  
            progress = max;  
        }  
        if(progress <= max){  
            this.progress = progress;  
            postInvalidate();  
        }  
          
    }  
      
      
    public int getCricleColor() {  
        return roundColor;  
    }  
  
    public void setCricleColor(int cricleColor) {  
        this.roundColor = cricleColor;  
    }  
  
    public int getCricleProgressColor() {  
        return roundProgressColor;  
    }  
  
    public void setCricleProgressColor(int cricleProgressColor) {  
        this.roundProgressColor = cricleProgressColor;  
    }  
  
    public int getTextColor() {  
        return textColor;  
    }  
  
    public void setTextColor(int textColor) {  
        this.textColor = textColor;  
    }  
  
    public float getTextSize() {  
        return textSize;  
    }  
  
    public void setTextSize(float textSize) {  
        this.textSize = textSize;  
    }  
  
    public float getRoundWidth() {  
        return roundWidth;  
    }  
  
    public void setRoundWidth(float roundWidth) {  
        this.roundWidth = roundWidth;  
    }  
  
  
}
********************style文件
<!-- 自定义控件属性 -->
    <declare-styleable name="RoundProgressBar">    
        <attr name="roundColor" format="color"/>  
        <attr name="roundProgressColor" format="color"/>  
        <attr name="roundWidth" format="dimension"></attr>  
        <attr name="textColor" format="color" />    
        <attr name="textSize" format="dimension" />   
        <attr name="max" format="integer"></attr>   
        <attr name="textIsDisplayable" format="boolean"></attr>  
        <attr name="style">  
            <enum name="STROKE" value="0"></enum>  
            <enum name="FILL" value="1"></enum>  
        </attr>  
    </declare-styleable>   
****************************xml 布局文件*************************
<com.example.circleprogressbar.RoundProgressBar 
	    android:id="@+id/rpb"
	    android:layout_width="match_parent"
	    android:layout_height="match_parent"
	    
	    android_custom:roundColor="#D1D1D1"    
        android_custom:roundProgressColor="@android:color/black"    
        android_custom:textColor="#9A32CD"    
        android_custom:textIsDisplayable="false"    
        android_custom:roundWidth="10dip"    
        android_custom:textSize="18sp"/>    
	    
	    />
******************************普通progresbar换背景**************************
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item  android:id="@android:id/background" >
<shape>
<corners
android:radius="5dip" />
<gradient
android:startColor="#dcdcdc"
android:endColor="#dcdcdc" />
</shape>
</item>
<!-- 设置进度条颜色(白色) -->
<item android:id="@android:id/progress" >
<clip >
<shape>
<corners
android:radius="10dip" />
<gradient
android:startColor="#ff0000"
android:endColor="#ff0000" />
</shape>
</clip>
</item>
</layer-list>
********************************************圆形图片********************************
package com.example.circleimage;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Xfermode;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
public abstract class MaskedImage extends ImageView {
	 private static final Xfermode MASK_XFERMODE;  
	    private Bitmap mask;  
	    private Paint paint;  
	  
	    static {  
	        PorterDuff.Mode localMode = PorterDuff.Mode.DST_IN;  
	        MASK_XFERMODE = new PorterDuffXfermode(localMode);  
	        
	    }  
	  
	    public MaskedImage(Context paramContext) {  
	        super(paramContext);  
	    }  
	  
	    public MaskedImage(Context paramContext, AttributeSet paramAttributeSet) {  
	        super(paramContext, paramAttributeSet);  
	    }  
	  
	    public MaskedImage(Context paramContext, AttributeSet paramAttributeSet, int paramInt) {  
	        super(paramContext, paramAttributeSet, paramInt);  
	    }  
	  
	    public abstract Bitmap createMask();  
	  
	    protected void onDraw(Canvas paramCanvas) {  
	        Drawable localDrawable = getDrawable();  
	        if (localDrawable == null)  
	            return;  
	        try {  
	            if (this.paint == null) {  
	                Paint localPaint1 = new Paint();  
	                this.paint = localPaint1;  
	                this.paint.setFilterBitmap(false);  
	                Paint localPaint2 = this.paint;  
	                Xfermode localXfermode1 = MASK_XFERMODE;  
	                @SuppressWarnings("unused")  
	                Xfermode localXfermode2 = localPaint2.setXfermode(localXfermode1);  
	            }  
	            float f1 = getWidth();  
	            float f2 = getHeight();  
	            int i = paramCanvas.saveLayer(0.0F, 0.0F, f1, f2, null, 31);  
	            int j = getWidth();  
	            int k = getHeight();  
	            localDrawable.setBounds(0, 0, j, k);  
	            localDrawable.draw(paramCanvas);  
	            if ((this.mask == null) || (this.mask.isRecycled())) {  
	                Bitmap localBitmap1 = createMask();  
	                this.mask = localBitmap1;  
	            }  
	            Bitmap localBitmap2 = this.mask;  
	            Paint localPaint3 = this.paint;  
	            paramCanvas.drawBitmap(localBitmap2, 0.0F, 0.0F, localPaint3);  
	            paramCanvas.restoreToCount(i);  
	            return;  
	        } catch (Exception localException) {  
	            StringBuilder localStringBuilder = new StringBuilder()  
	                    .append("Attempting to draw with recycled bitmap. View ID = ");  
	            System.out.println("localStringBuilder=="+localStringBuilder);  
	        }  
	    }  
	
}
**********************************************musk****************
package com.example.circleimage;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Xfermode;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
public abstract class MaskedImage extends ImageView {
	 private static final Xfermode MASK_XFERMODE;  
	    private Bitmap mask;  
	    private Paint paint;  
	  
	    static {  
	        PorterDuff.Mode localMode = PorterDuff.Mode.DST_IN;  
	        MASK_XFERMODE = new PorterDuffXfermode(localMode);  
	        
	    }  
	  
	    public MaskedImage(Context paramContext) {  
	        super(paramContext);  
	    }  
	  
	    public MaskedImage(Context paramContext, AttributeSet paramAttributeSet) {  
	        super(paramContext, paramAttributeSet);  
	    }  
	  
	    public MaskedImage(Context paramContext, AttributeSet paramAttributeSet, int paramInt) {  
	        super(paramContext, paramAttributeSet, paramInt);  
	    }  
	  
	    public abstract Bitmap createMask();  
	  
	    protected void onDraw(Canvas paramCanvas) {  
	        Drawable localDrawable = getDrawable();  
	        if (localDrawable == null)  
	            return;  
	        try {  
	            if (this.paint == null) {  
	                Paint localPaint1 = new Paint();  
	                this.paint = localPaint1;  
	                this.paint.setFilterBitmap(false);  
	                Paint localPaint2 = this.paint;  
	                Xfermode localXfermode1 = MASK_XFERMODE;  
	                @SuppressWarnings("unused")  
	                Xfermode localXfermode2 = localPaint2.setXfermode(localXfermode1);  
	            }  
	            float f1 = getWidth();  
	            float f2 = getHeight();  
	            int i = paramCanvas.saveLayer(0.0F, 0.0F, f1, f2, null, 31);  
	            int j = getWidth();  
	            int k = getHeight();  
	            localDrawable.setBounds(0, 0, j, k);  
	            localDrawable.draw(paramCanvas);  
	            if ((this.mask == null) || (this.mask.isRecycled())) {  
	                Bitmap localBitmap1 = createMask();  
	                this.mask = localBitmap1;  
	            }  
	            Bitmap localBitmap2 = this.mask;  
	            Paint localPaint3 = this.paint;  
	            paramCanvas.drawBitmap(localBitmap2, 0.0F, 0.0F, localPaint3);  
	            paramCanvas.restoreToCount(i);  
	            return;  
	        } catch (Exception localException) {  
	            StringBuilder localStringBuilder = new StringBuilder()  
	                    .append("Attempting to draw with recycled bitmap. View ID = ");  
	            System.out.println("localStringBuilder=="+localStringBuilder);  
	        }  
	    }  
	
}
**********************************cirimageview*******************************888
package com.example.circleimage;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
public class CircularImage extends MaskedImage {
	public CircularImage(Context paramContext) {  
        super(paramContext);  
    }  
  
    public CircularImage(Context paramContext, AttributeSet paramAttributeSet) {  
        super(paramContext, paramAttributeSet);  
    }  
  
    public CircularImage(Context paramContext, AttributeSet paramAttributeSet, int paramInt) {  
        super(paramContext, paramAttributeSet, paramInt);  
    }  
  
    public Bitmap createMask() {  
        int i = getWidth();  
        int j = getHeight();  
        Bitmap.Config localConfig = Bitmap.Config.ARGB_8888;  
        Bitmap localBitmap = Bitmap.createBitmap(i, j, localConfig);  
        Canvas localCanvas = new Canvas(localBitmap);  
        Paint localPaint = new Paint(1);  
        localPaint.setColor(-16777216);  
        float f1 = getWidth();  
        float f2 = getHeight();  
        RectF localRectF = new RectF(0.0F, 0.0F, 50, 50);  
        localCanvas.drawOval(localRectF, localPaint);  
        return localBitmap;  
}
}
*************************************quickbar******************************8
package com.droid;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.text.style.TypefaceSpan;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
public class MyLetterListView extends View {
	
	OnTouchingLetterChangedListener onTouchingLetterChangedListener;
	String[] b = {"#","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"};
	int choose = -1;
	Paint paint = new Paint();
	boolean showBkg = false;
	public MyLetterListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
	}
	public MyLetterListView(Context context, AttributeSet attrs) {
		super(context, attrs);
	}
	public MyLetterListView(Context context) {
		super(context);
	}
	
	@Override
	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);
		if(showBkg){
		    canvas.drawColor(Color.parseColor("#40000000"));
		}
		
	    int height = getHeight();
	    int width = getWidth();
	    int singleHeight = height / b.length;
	    for(int i=0;i<b.length;i++){
	       paint.setColor(Color.WHITE);
	       paint.setTypeface(Typeface.DEFAULT_BOLD);
	       paint.setAntiAlias(true);
	       if(i == choose){
	    	   paint.setColor(Color.parseColor("#3399ff"));
	    	   paint.setFakeBoldText(true);
	       }
	       float xPos = width/2  - paint.measureText(b[i])/2;
	       float yPos = singleHeight * i + singleHeight;
	       canvas.drawText(b[i], xPos, yPos, paint);
	       paint.reset();
	    }
	   
	}
	
	@Override
	public boolean dispatchTouchEvent(MotionEvent event) {
		final int action = event.getAction();
	    final float y = event.getY();
	    final int oldChoose = choose;
	    final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener;
	    final int c = (int) (y/getHeight()*b.length);
	    
		switch (action) {
			case MotionEvent.ACTION_DOWN:
				showBkg = true;
				if(oldChoose != c && listener != null){
					if(c > 0 && c< b.length){
						listener.onTouchingLetterChanged(b[c]);
						choose = c;
						invalidate();
					}
				}
				
				break;
			case MotionEvent.ACTION_MOVE:
				if(oldChoose != c && listener != null){
					if(c > 0 && c< b.length){
						listener.onTouchingLetterChanged(b[c]);
						choose = c;
						invalidate();
					}
				}
				break;
			case MotionEvent.ACTION_UP:
				showBkg = false;
				choose = -1;
				invalidate();
				break;
		}
		return true;
	}
	@Override
	public boolean onTouchEvent(MotionEvent event) {
		return super.onTouchEvent(event);
	}
	public void setOnTouchingLetterChangedListener(
			OnTouchingLetterChangedListener onTouchingLetterChangedListener) {
		this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;
	}
	public interface OnTouchingLetterChangedListener{
		public void onTouchingLetterChanged(String s);
	}
	
}
*****************************************mainactivity***************************
package com.droid;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.regex.Pattern;
import android.app.Activity;
import android.content.AsyncQueryHandler;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.graphics.PixelFormat;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.WindowManager;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import com.droid.MyLetterListView.OnTouchingLetterChangedListener;
public class Activity01 extends Activity {
	private BaseAdapter adapter;  
    private ListView personList;
    private TextView overlay;
    private MyLetterListView letterListView;
    private AsyncQueryHandler asyncQuery;  
    private static final String NAME = "name", NUMBER = "number", SORT_KEY = "sort_key";
    private HashMap<String, Integer> alphaIndexer;//存放存在的汉语拼音首字母和与之对应的列表位置
    private String[] sections;//存放存在的汉语拼音首字母
    private Handler handler;
    private OverlayThread overlayThread;
  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
        
        personList = (ListView) findViewById(R.id.list_view);
        letterListView = (MyLetterListView) findViewById(R.id.MyLetterListView01);
        letterListView.setOnTouchingLetterChangedListener(new LetterListViewListener());
        
        asyncQuery = new MyAsyncQueryHandler(getContentResolver());
        alphaIndexer = new HashMap<String, Integer>();
        handler = new Handler();
        overlayThread = new OverlayThread();
        initOverlay();
    }  
  
    @Override  
    protected void onResume() {  
        super.onResume();  
        Uri uri = Uri.parse("content://com.android.contacts/data/phones");  
        String[] projection = { "_id", "display_name", "data1", "sort_key" };  
        asyncQuery.startQuery(0, null, uri, projection, null, null,  
                "sort_key COLLATE LOCALIZED asc");
    }  
  
    //查询联系人
    private class MyAsyncQueryHandler extends AsyncQueryHandler {  
  
        public MyAsyncQueryHandler(ContentResolver cr) {  
            super(cr);  
  
        }  
  
        @Override  
        protected void onQueryComplete(int token, Object cookie, Cursor cursor) {  
            if (cursor != null && cursor.getCount() > 0) {  
                List<ContentValues> list = new ArrayList<ContentValues>();  
                cursor.moveToFirst();  
                for (int i = 0; i < cursor.getCount(); i++) {
                    ContentValues cv = new ContentValues();  
                    cursor.moveToPosition(i);  
                    String name = cursor.getString(1);  
                    String number = cursor.getString(2);  
                    String sortKey = cursor.getString(3);
                    if (number.startsWith("+86")) {  
                        cv.put(NAME, name);  
                        cv.put(NUMBER, number.substring(3));  //去掉+86
                        cv.put(SORT_KEY, sortKey);  
                    } else {  
                        cv.put(NAME, name);  
                        cv.put(NUMBER, number);  
                        cv.put(SORT_KEY, sortKey);  
                    }  
                    list.add(cv);  
                }  
                if (list.size() > 0) {  
                    setAdapter(list);  
                }  
            }  
        }  
  
    }  
  
    private void setAdapter(List<ContentValues> list) {
    	adapter = new ListAdapter(this, list);
        personList.setAdapter(adapter);  
  
    }
    
    private class ListAdapter extends BaseAdapter {
    	 private LayoutInflater inflater;  
         private List<ContentValues> list;
    	
    	public ListAdapter(Context context, List<ContentValues> list) {
    		this.inflater = LayoutInflater.from(context);
    		this.list = list;
    		alphaIndexer = new HashMap<String, Integer>();
    		sections = new String[list.size()];
    		
    		for (int i = 0; i < list.size(); i++) {
    			//当前汉语拼音首字母
    			String currentStr = getAlpha(list.get(i).getAsString(SORT_KEY));
    			//上一个汉语拼音首字母,如果不存在为“ ”
                String previewStr = (i - 1) >= 0 ? getAlpha(list.get(i - 1).getAsString(SORT_KEY)) : " ";
                if (!previewStr.equals(currentStr)) {
                	String name = getAlpha(list.get(i).getAsString(SORT_KEY));
                	alphaIndexer.put(name, i);  
                	sections[i] = name; 
                }
            }
    	}
    	
		@Override
		public int getCount() {
			return list.size();
		}
		@Override
		public Object getItem(int position) {
			return list.get(position);
		}
		@Override
		public long getItemId(int position) {
			return position;
		}
		
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			ViewHolder holder;
			if (convertView == null) {  
                convertView = inflater.inflate(R.layout.list_item, null);
                holder = new ViewHolder();  
                holder.alpha = (TextView) convertView.findViewById(R.id.alpha);  
                holder.name = (TextView) convertView.findViewById(R.id.name);  
                holder.number = (TextView) convertView.findViewById(R.id.number);  
                convertView.setTag(holder);  
            } else {  
                holder = (ViewHolder) convertView.getTag();  
            }  
            ContentValues cv = list.get(position);  
            holder.name.setText(cv.getAsString(NAME));
            holder.number.setText(cv.getAsString(NUMBER));
            String currentStr = getAlpha(list.get(position).getAsString(SORT_KEY));
            String previewStr = (position - 1) >= 0 ? getAlpha(list.get(position - 1).getAsString(SORT_KEY)) : " ";
            if (!previewStr.equals(currentStr)) {  
                holder.alpha.setVisibility(View.VISIBLE);
                holder.alpha.setText(currentStr);
            } else {  
                holder.alpha.setVisibility(View.GONE);
            }  
            return convertView;  
		}
		
		private class ViewHolder {
			TextView alpha;  
            TextView name;  
            TextView number;
		}
    	
    }
    
    //初始化汉语拼音首字母弹出提示框
    private void initOverlay() {
    	LayoutInflater inflater = LayoutInflater.from(this);
    	overlay = (TextView) inflater.inflate(R.layout.overlay, null);
    	overlay.setVisibility(View.INVISIBLE);
		WindowManager.LayoutParams lp = new WindowManager.LayoutParams(
				LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT,
				WindowManager.LayoutParams.TYPE_APPLICATION,
				WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
						| WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
				PixelFormat.TRANSLUCENT);
		WindowManager windowManager = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);
		windowManager.addView(overlay, lp);
    }
    
    private class LetterListViewListener implements OnTouchingLetterChangedListener{
		@Override
		public void onTouchingLetterChanged(final String s) {
			if(alphaIndexer.get(s) != null) {
				int position = alphaIndexer.get(s);
				personList.setSelection(position);
				overlay.setText(sections[position]);
				overlay.setVisibility(View.VISIBLE);
				handler.removeCallbacks(overlayThread);
				//延迟一秒后执行,让overlay为不可见
				handler.postDelayed(overlayThread, 1500);
			} 
		}
    	
    }
    
    //设置overlay不可见
    private class OverlayThread implements Runnable {
		@Override
		public void run() {
			overlay.setVisibility(View.GONE);
		}
    	
    }
    
    
	//获得汉语拼音首字母
    private String getAlpha(String str) {  
        if (str == null) {  
            return "#";  
        }  
  
        if (str.trim().length() == 0) {  
            return "#";  
        }  
  
        char c = str.trim().substring(0, 1).charAt(0);  
        // 正则表达式,判断首字母是否是英文字母  
        Pattern pattern = Pattern.compile("^[A-Za-z]+$");  
        if (pattern.matcher(c + "").matches()) {  
            return (c + "").toUpperCase();  
        } else {  
            return "#";  
        }  
    }  
  
}
******************************listItem*********************************
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent">
	<TextView
		android:id="@+id/alpha"
		android:layout_width="fill_parent"
  		android:layout_height="wrap_content"
  		android:paddingLeft="13dip"
  		android:background="#333333"
		android:textColor="#99CCFF"
		android:textAppearance="?android:textAppearanceMedium"
		android:visibility="gone" />
		
	<ImageView
		android:id="@+id/image_view"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_alignParentLeft="true"
		android:layout_marginRight="5.0dip"
		android:src="@drawable/contact_list_icon"
		android:layout_below="@id/alpha" />
		
    <TextView
    	android:id="@+id/name"
    	android:textAppearance="?android:textAppearanceMedium"
    	android:layout_width="wrap_content"
    	android:layout_height="wrap_content"
    	android:layout_marginLeft="2.0dip"
    	android:layout_marginTop="6.0dip"
    	android:layout_marginRight="5.0dip"
    	android:singleLine="true"
    	android:layout_toRightOf="@id/image_view"
    	android:layout_alignTop="@id/image_view" />
    	
    <TextView
    	android:id="@+id/number"
    	android:textAppearance="?android:textAppearanceSmall"
    	android:ellipsize="marquee"
    	android:layout_width="wrap_content"
    	android:layout_height="wrap_content"
    	android:singleLine="true"
    	android:textColor="#AAAAAA"
    	android:layout_below="@id/name"
    	android:layout_alignLeft="@id/name"
    	android:layout_alignWithParentIfMissing="true" />
    	
</RelativeLayout>
****************************main.xml
<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:orientation="vertical"  
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent" > 
     
    <ListView android:id="@+id/list_view" 
		android:layout_height="wrap_content" 
		android:layout_width="fill_parent"
		android:scrollbars="none"
		android:cacheColorHint="#00000000" />
    <com.droid.MyLetterListView 
    	android:id="@+id/MyLetterListView01" 
		android:background="#40000000" 
		android:layout_width="30dip" 
		android:layout_height="fill_parent"
		android:layout_alignParentRight="true" />
</RelativeLayout> 
***************************overlay.xml*************************************
<?xml version="1.0" encoding="utf-8"?>
<TextView
  	xmlns:android="http://schemas.android.com/apk/res/android"
  	android:textSize="70sp"
    android:textColor="#3399ff"
    android:background="#ffffff"  
    android:minWidth="80dip"  
    android:maxWidth="80dip"  
    android:padding="5dip"
    android:gravity="center" 
/>
原文:http://www.cnblogs.com/hanyong/p/4417894.html