通讯录侧边栏快速滑动效果的实现
那，我原创的文章比较少，所以基本上都是自己看了，然后稍加修改的！
综合这两个帖子：
http://blog.csdn.net/ilysony/article/details/6292771
http://blog.csdn.net/yan_daoqiu/article/details/6393300
中文的还没去实验
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我不知道怎么传图 - - ！
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大概思路就是在listView里面设置了 section,然后侧边栏是一个自定义的组件
侧边栏ontouch中会去 让listview 跳到相应位置list.setSelection();
listview中设置onScroll监听器，滑动时候让中间弹出windows,不滑动时候隐藏
window中显示的就是首字母。
侧边栏代码
public class SideBar extends View{private char[] l; private SectionIndexer sectionIndexter = null; private ListView list; private final int m_nItemHeight = 29; public SideBar(Context context) { super(context); init(); } public SideBar(Context context, AttributeSet attrs) { super(context, attrs); init(); } private void init() { l = new char[] { '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' }; setBackgroundColor(0x44FFFFFF); } public SideBar(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); } public void setListView(ListView _list) { list = _list; sectionIndexter = (SectionIndexer) _list.getAdapter(); } public boolean onTouchEvent(MotionEvent event) { super.onTouchEvent(event); int i = (int) event.getY(); int idx = i / m_nItemHeight; if (idx >= l.length) { idx = l.length - 1; } else if (idx < 0) { idx = 0; } if (event.getAction() == MotionEvent.ACTION_DOWN || event.getAction() == MotionEvent.ACTION_MOVE) { if (sectionIndexter == null) { sectionIndexter = (SectionIndexer) list.getAdapter(); } int position = sectionIndexter.getPositionForSection(l[idx]); if (position == -1) { return true; } list.setSelection(position); } return true; } protected void onDraw(Canvas canvas) { Paint paint = new Paint(); paint.setColor(0xFFA6A9AA); paint.setTextSize(20); paint.setTextAlign(Paint.Align.CENTER); float widthCenter = getMeasuredWidth() / 2; for (int i = 0; i < l.length; i++) { canvas.drawText(String.valueOf(l[i]), widthCenter, m_nItemHeight + (i * m_nItemHeight), paint); } super.onDraw(canvas); } }public class MyAdapter extends BaseAdapter implements SectionIndexer{private ArrayList<String> stringArray; private Context context; public MyAdapter(Context _context, ArrayList<String> arr) { stringArray = arr; context = _context; } public int getCount() { return stringArray.size(); } public Object getItem(int arg0) { return stringArray.get(arg0); } public long getItemId(int arg0) { return 0; } public View getView(int position, View v, ViewGroup parent) { LayoutInflater inflate = ((Activity) context).getLayoutInflater(); View view = (View) inflate.inflate(R.layout.listview_row, null); LinearLayout header = (LinearLayout) view.findViewById(R.id.section); String label = stringArray.get(position); char firstChar = label.toUpperCase().charAt(0); if (position == 0) { setSection(header, label); } else { String preLabel = stringArray.get(position - 1); char preFirstChar = preLabel.toUpperCase().charAt(0); if (firstChar != preFirstChar) { setSection(header, label); } else { header.setVisibility(View.GONE); } } TextView textView = (TextView) view.findViewById(R.id.textView); textView.setText(label); return view; } private void setSection(LinearLayout header, String label) { TextView text = new TextView(context); header.setBackgroundColor(0xffaabbcc); text.setTextColor(Color.WHITE); text.setText(label.substring(0, 1).toUpperCase()); text.setTextSize(20); text.setPadding(5, 0, 0, 0); text.setGravity(Gravity.CENTER_VERTICAL); header.addView(text); } public int getPositionForSection(int section) { if (section == 35) { return 0; } for (int i = 0; i < stringArray.size(); i++) { String l = stringArray.get(i); char firstChar = l.toUpperCase().charAt(0); if (firstChar == section) { return i; } } return -1; } public int getSectionForPosition(int arg0) { return 0; } public Object[] getSections() { return null; } }TextView overlay = (TextView) View.inflate(this, R.layout.overlay, null); getWindowManager() .addView( overlay, 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) ); list.setOnScrollListener(onScroll);OnScrollListener onScroll = new OnScrollListener() { boolean visible; @Override public void onScrollStateChanged(AbsListView view, int scrollState) { visible = true; if (scrollState == ListView.OnScrollListener.SCROLL_STATE_IDLE) { overlay.setVisibility(View.INVISIBLE); } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { if (visible) { overlay.setText(list.getItemAtPosition(firstVisibleItem).toString().substring(0, 1)); overlay.setVisibility(View.VISIBLE); } }};