学步园

1. Main.xml

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

2. listview_row.xml

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

3. MyAdapter.java

package android.test;<br /> import java.util.ArrayList;<br /> import android.app.Activity;<br /> import android.content.Context;<br /> import android.graphics.Color;<br /> import android.view.Gravity;<br /> import android.view.LayoutInflater;<br /> import android.view.View;<br /> import android.view.ViewGroup;<br /> import android.widget.BaseAdapter;<br /> import android.widget.LinearLayout;<br /> import android.widget.SectionIndexer;<br /> import android.widget.TextView;<br /> public class MyAdapter extends BaseAdapter implements SectionIndexer {<br /> private ArrayList<String> stringArray;<br /> private Context context;<br /> public MyAdapter(Context _context, ArrayList<String> arr) {<br /> stringArray = arr;<br /> context = _context;<br /> }<br /> public int getCount() {<br /> return stringArray.size();<br /> }<br /> public Object getItem(int arg0) {<br /> return stringArray.get(arg0);<br /> }<br /> public long getItemId(int arg0) {<br /> return 0;<br /> }<br /> public View getView(int position, View v, ViewGroup parent) {<br /> LayoutInflater inflate = ((Activity) context).getLayoutInflater();<br /> View view = (View) inflate.inflate(R.layout.listview_row, null);<br /> LinearLayout header = (LinearLayout) view.findViewById(R.id.section);<br /> String label = stringArray.get(position);<br /> char firstChar = label.toUpperCase().charAt(0);<br /> if (position == 0) {<br /> setSection(header, label);<br /> } else {<br /> String preLabel = stringArray.get(position - 1);<br /> char preFirstChar = preLabel.toUpperCase().charAt(0);<br /> if (firstChar != preFirstChar) {<br /> setSection(header, label);<br /> } else {<br /> header.setVisibility(View.GONE);<br /> }<br /> }<br /> TextView textView = (TextView) view.findViewById(R.id.textView);<br /> textView.setText(label);<br /> return view;<br /> }<br /> private void setSection(LinearLayout header, String label) {<br /> TextView text = new TextView(context);<br /> header.setBackgroundColor(0xffaabbcc);<br /> text.setTextColor(Color.WHITE);<br /> text.setText(label.substring(0, 1).toUpperCase());<br /> text.setTextSize(20);<br /> text.setPadding(5, 0, 0, 0);<br /> text.setGravity(Gravity.CENTER_VERTICAL);<br /> header.addView(text);<br /> }<br /> public int getPositionForSection(int section) {<br /> if (section == 35) {<br /> return 0;<br /> }<br /> for (int i = 0; i < stringArray.size(); i++) {<br /> String l = stringArray.get(i);<br /> char firstChar = l.toUpperCase().charAt(0);<br /> if (firstChar == section) {<br /> return i;<br /> }<br /> }<br /> return -1;<br /> }<br /> public int getSectionForPosition(int arg0) {<br /> return 0;<br /> }<br /> public Object[] getSections() {<br /> return null;<br /> }<br /> }

4.  SideBar.java

package android.test;<br /> import android.content.Context;<br /> import android.graphics.Canvas;<br /> import android.graphics.Paint;<br /> import android.util.AttributeSet;<br /> import android.view.MotionEvent;<br /> import android.view.View;<br /> import android.widget.ListView;<br /> import android.widget.SectionIndexer;<br /> public class SideBar extends View {<br /> private char[] l;<br /> private SectionIndexer sectionIndexter = null;<br /> private ListView list;<br /> private final int m_nItemHeight = 29;<br /> public SideBar(Context context) {<br /> super(context);<br /> init();<br /> }<br /> public SideBar(Context context, AttributeSet attrs) {<br /> super(context, attrs);<br /> init();<br /> }<br /> private void init() {<br /> l = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',<br /> 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };<br /> setBackgroundColor(0x44FFFFFF);<br /> }<br /> public SideBar(Context context, AttributeSet attrs, int defStyle) {<br /> super(context, attrs, defStyle);<br /> init();<br /> }<br /> public void setListView(ListView _list) {<br /> list = _list;<br /> sectionIndexter = (SectionIndexer) _list.getAdapter();<br /> }<br /> public boolean onTouchEvent(MotionEvent event) {<br /> super.onTouchEvent(event);<br /> int i = (int) event.getY();<br /> int idx = i / m_nItemHeight;<br /> if (idx >= l.length) {<br /> idx = l.length - 1;<br /> } else if (idx < 0) {<br /> idx = 0;<br /> }<br /> if (event.getAction() == MotionEvent.ACTION_DOWN || event.getAction() == MotionEvent.ACTION_MOVE) {<br /> if (sectionIndexter == null) {<br /> sectionIndexter = (SectionIndexer) list.getAdapter();<br /> }<br /> int position = sectionIndexter.getPositionForSection(l[idx]);<br /> if (position == -1) {<br /> return true;<br /> }<br /> list.setSelection(position);<br /> }<br /> return true;<br /> }<br /> protected void onDraw(Canvas canvas) {<br /> Paint paint = new Paint();<br /> paint.setColor(0xFFA6A9AA);<br /> paint.setTextSize(20);<br /> paint.setTextAlign(Paint.Align.CENTER);<br /> float widthCenter = getMeasuredWidth() / 2;<br /> for (int i = 0; i < l.length; i++) {<br /> canvas.drawText(String.valueOf(l[i]), widthCenter, m_nItemHeight + (i * m_nItemHeight), paint);<br /> }<br /> super.onDraw(canvas);<br /> }<br /> }

5. Main.java

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