SectionIndexer 的使用（联系人分类索引）

转自：SectionIndexer 的使用（联系人分类索引）

 // 获取标题栏索引
 int position = sectionIndexter.getPositionForSection(l[idx]);
             if (position == -1) {
                 return true;
             }
     // 设置调整到指定区域
             list.setSelection(position);

 1. Main.xml 

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent">
 <ListView android:id="@+id/myListView"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
 />
 <android.test.SideBar
     android:id = "@+id/sideBar"
     android:layout_height="fill_parent"
     android:layout_width="22px"
     android:layout_alignParentRight="true"
 />
 </RelativeLayout>

 2. listview_row.xml 

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="vertical"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content">
 <LinearLayout
     android:id="@+id/section"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
 />
 <TextView android:id="@+id/textView"
     android:layout_width="wrap_content"
     android:layout_height="80sp"
     android:textSize="45sp"
 />
 </LinearLayout>

 3. MyAdapter.java 

 package android.test;
 import java.util.ArrayList;
 import android.app.Activity;
 import android.content.Context;
 import android.graphics.Color;
 import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
 import android.widget.LinearLayout;
 import android.widget.SectionIndexer;
 import android.widget.TextView;
 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;
     }
 }

  4.  SideBar.java 

 package android.test;
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 import android.view.View;
 import android.widget.ListView;
 import android.widget.SectionIndexer;
 public class SideBar extends View {
     private char[] l;
     private SectionIndexer sectionIndexter = null;
     private ListView list;
     private final int m_nItemHeight = 60;
     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(getMeasuredHeight()/26);
         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);
     }
 }

 5. Main.java 

 package android.test;
 import java.util.ArrayList;
 import android.app.Activity;
 import android.os.Bundle;
 import android.widget.ListView;
 public class Main extends Activity {
     /** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         ListView list = (ListView) findViewById(R.id.myListView);
         ArrayList<String> stringList = InitListViewData();
         MyAdapter adapter = new MyAdapter(this, stringList);
         list.setAdapter(adapter);
         SideBar indexBar = (SideBar) findViewById(R.id.sideBar);
         indexBar.setListView(list);
     }
     private ArrayList<String> InitListViewData() {
         ArrayList<String> stringList = new ArrayList<String>();
         stringList.add("aback");
         stringList.add("abash");
         stringList.add("abbey");
         stringList.add("abhor");
         stringList.add("abide");
         stringList.add("abuse");
         stringList.add("candidate");
         stringList.add("capture");
         stringList.add("careful");
         stringList.add("catch");
         stringList.add("cause");
         stringList.add("celebrate");
         stringList.add("forever");
         stringList.add("fable");
         stringList.add("fidelity");
         stringList.add("fox");
         stringList.add("funny");
         stringList.add("fail");
         stringList.add("jail");
         stringList.add("jade");
         stringList.add("jailor");
         stringList.add("january");
         stringList.add("jasmine");
         stringList.add("jazz");
         stringList.add("zero");
         stringList.add("zoo");
         stringList.add("zeus");
         stringList.add("zebra");
         stringList.add("zest");
         stringList.add("zing");
         return stringList;
     }
 }