求android实现未读短信图标数字提示效果

public static Bitmap generatorContactCountIcon(Bitmap icon,int i,CommonActivity context){ 
        //初始化画布 
        int iconSize=(int)context.getResources().getDimension(android.R.dimen.app_icon_size); 
        Bitmap contactIcon=Bitmap.createBitmap(icon.getWidth(), icon.getHeight(), Config.ARGB_8888); 
        Canvas canvas=new Canvas(contactIcon); 
        //拷贝图片 
        Paint iconPaint=new Paint(); 
        iconPaint.setDither(true);//防抖动 
        iconPaint.setFilterBitmap(true);//用来对Bitmap进行滤波处理，这样，当你选择Drawable时，会有抗锯齿的效果 
        Rect src=new Rect(0, 0, icon.getWidth(), icon.getHeight()); 
        Rect dst=new Rect(0, 0, iconSize, iconSize); 
        canvas.drawBitmap(icon, src, src, iconPaint); 
         
        //在图片上创建一个覆盖的联系人个数 
        int contacyCount=i; 
        //启用抗锯齿和使用设备的文本字距 
        Paint countPaint=new Paint(Paint.ANTI_ALIAS_FLAG|Paint.DEV_KERN_TEXT_FLAG); 
        countPaint.setColor(Color.WHITE); 
        countPaint.setTextSize(16f); 
        countPaint.setTypeface(Typeface.DEFAULT_BOLD); 
        canvas.drawText(String.valueOf(contacyCount), iconSize-17, 23, countPaint);
        return contactIcon; 
    }画上去