android - 如何使用 fastscroll 和 albhabet 索引器实现 ListView

Question

请帮助我在这 2 天里感到震惊。我想在联系人应用程序/下图中实现一个带有 fastscroll 和 albhabet 索引器的 ListView。我正在使用 SimpleAdapter 来填充 ListView。从图中可以看出，通过从右侧的字母表索引器中选择一个字母，listView 选择会转到相应的 ListItem。请分享一些例子。提前谢谢你。EX:下面是我的代码，它只是对字母表进行排序，当我点击与 E 相关的 E 字母表数据是 gng 到 diaplay ..但是当我触摸字母表时它没有在中间显示 E 文本框。

如何在中间显示 E 文本框..当我触摸 fastscroll 中间文本框时必须显示。

主 Activity .java

   public class MainActivity extends Activity implements SearchView.OnQueryTextListener,SearchView.OnCloseListener {

private ListView listView;
private SearchView search;
EfficientAdapter objectAdapter;
EfficientAdapter2 objectAdapter1;
int textlength=0;
private CheckBox checkStat, checkRoutine, checkTat;
 private GestureDetector mGestureDetector;

    // x and y coordinates within our side index
    private static float sideIndexX;
    private static float sideIndexY;

    // height of side index
    private int sideIndexHeight;

    // number of items in the side index
    private int indexListSize;

    // list with items for side index
    private ArrayList<Object[]> indexList = null;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
   setContentView(R.layout.homempleb);
   Log.i("scan"," txtScanResult ");

   Arrays.sort(CountriesList.name);
ActionItem nextItem     = new ActionItem(); 
final QuickAction quickAction = new QuickAction(this, QuickAction.VERTICAL);
quickAction.addActionItem(nextItem);
quickAction.setOnDismissListener(new QuickAction.OnDismissListener()           {            
    @Override
    public void onDismiss() {
        Toast.makeText(getApplicationContext(), "Dismissed", Toast.LENGTH_SHORT).show();
    }
});


listView = (ListView) findViewById(R.id.homelistView);
listView.setTextFilterEnabled(true);
objectAdapter = new EfficientAdapter(this);
 mGestureDetector = new GestureDetector(this, new SideIndexGestureListener());
listView.setAdapter(objectAdapter);


}
 @Override
    public boolean onTouchEvent(MotionEvent event)
    {
        if (mGestureDetector.onTouchEvent(event))
        {
            return true;
        } else
        {
            return false;
        }
    }

    private ArrayList<Object[]> createIndex(String[] strArr)
    {
        ArrayList<Object[]> tmpIndexList = new ArrayList<Object[]>();
        Object[] tmpIndexItem = null;

        int tmpPos = 0;
        String tmpLetter = "";
        String currentLetter = null;
        String strItem = null;

        for (int j = 0; j < strArr.length; j++)
        {
            strItem = strArr[j];
            currentLetter = strItem.substring(0, 1);

            // every time new letters comes
            // save it to index list
            if (!currentLetter.equals(tmpLetter))
            {
                tmpIndexItem = new Object[3];
                tmpIndexItem[0] = tmpLetter;
                tmpIndexItem[1] = tmpPos - 1;
                tmpIndexItem[2] = j - 1;

                tmpLetter = currentLetter;
                tmpPos = j + 1;

                tmpIndexList.add(tmpIndexItem);
            }
        }

        // save also last letter
        tmpIndexItem = new Object[3];
        tmpIndexItem[0] = tmpLetter;
        tmpIndexItem[1] = tmpPos - 1;
        tmpIndexItem[2] = strArr.length - 1;
        tmpIndexList.add(tmpIndexItem);

        // and remove first temporary empty entry
        if (tmpIndexList != null && tmpIndexList.size() > 0)
        {
            tmpIndexList.remove(0);
        }

        return tmpIndexList;
    }
    @Override
    public void onWindowFocusChanged(boolean hasFocus)
    {
        super.onWindowFocusChanged(hasFocus);

        final ListView listView = (ListView) findViewById(R.id.homelistView);
        LinearLayout sideIndex = (LinearLayout) findViewById(R.id.sideIndex);
        sideIndexHeight = sideIndex.getHeight();
        sideIndex.removeAllViews();

        // TextView for every visible item
        TextView tmpTV = null;

        // we'll create the index list
        indexList = createIndex(CountriesList.name);

        // number of items in the index List
        indexListSize = indexList.size();

        // maximal number of item, which could be displayed
        int indexMaxSize = (int) Math.floor(sideIndex.getHeight() / 20);

        int tmpIndexListSize = indexListSize;

        // handling that case when indexListSize > indexMaxSize
        while (tmpIndexListSize > indexMaxSize)
        {
            tmpIndexListSize = tmpIndexListSize / 2;
        }

        // computing delta (only a part of items will be displayed to save a
        // place)
        double delta = indexListSize / tmpIndexListSize;

        String tmpLetter = null;
        Object[] tmpIndexItem = null;

        // show every m-th letter
        for (double i = 1; i <= indexListSize; i = i + delta)
        {
            tmpIndexItem = indexList.get((int) i - 1);
            tmpLetter = tmpIndexItem[0].toString();
            tmpTV = new TextView(this);
            tmpTV.setText(tmpLetter);
            tmpTV.setGravity(Gravity.CENTER);
            tmpTV.setTextSize(20);
            LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, 1);
            tmpTV.setLayoutParams(params);
            sideIndex.addView(tmpTV);
        }

        // and set a touch listener for it
        sideIndex.setOnTouchListener(new OnTouchListener()
        {
            @Override
            public boolean onTouch(View v, MotionEvent event)
            {
                // now you know coordinates of touch
                sideIndexX = event.getX();
                sideIndexY = event.getY();

                // and can display a proper item it country list
                displayListItem();

                return false;
            }
        });
    }

    class SideIndexGestureListener extends
    GestureDetector.SimpleOnGestureListener
 {
   @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2,
        float distanceX, float distanceY)
{
    // we know already coordinates of first touch
    // we know as well a scroll distance
    sideIndexX = sideIndexX - distanceX;
    sideIndexY = sideIndexY - distanceY;

    // when the user scrolls within our side index
    // we can show for every position in it a proper
    // item in the country list
    if (sideIndexX >= 0 && sideIndexY >= 0)
    {
        displayListItem();
    }

    return super.onScroll(e1, e2, distanceX, distanceY);
}
  }

    public void displayListItem()
    {
    // compute number of pixels for every side index item
    double pixelPerIndexItem = (double) sideIndexHeight / indexListSize;

    // compute the item index for given event position belongs to
    int itemPosition = (int) (sideIndexY / pixelPerIndexItem);

    // compute minimal position for the item in the list
    int minPosition = (int) (itemPosition * pixelPerIndexItem);

    // get the item (we can do it since we know item index)
    Object[] indexItem = indexList.get(itemPosition);

    // and compute the proper item in the country list
    int indexMin = Integer.parseInt(indexItem[1].toString());
    int indexMax = Integer.parseInt(indexItem[2].toString());
    int indexDelta = Math.max(1, indexMax - indexMin);

    double pixelPerSubitem = pixelPerIndexItem / indexDelta;
    int subitemPosition = (int) (indexMin + (sideIndexY - minPosition) / pixelPerSubitem);

    ListView listView = (ListView) findViewById(R.id.homelistView);
    listView.setSelection(subitemPosition);
    }

EfficientAdapter.java

 public class EfficientAdapter extends BaseAdapter {
 private LayoutInflater mInflater;
  private Context context;

  public EfficientAdapter(Context context) {
mInflater = LayoutInflater.from(context);
this.context=context;

  }


 public int getCount() {
return CountriesList.name.length;
 }

     public Object getItem(int position) {

return position;
 }

      public long getItemId(int position) {
return position;
   }

         public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
    convertView = mInflater.inflate(R.layout.homemplebrowview, null);
    holder = new ViewHolder();
    holder.text1 = (TextView) convertView
            .findViewById(R.id.name);
    holder.text2 = (TextView) convertView
            .findViewById(R.id.mrn);
    holder.text3 = (TextView) convertView
            .findViewById(R.id.date);
    holder.text4 = (TextView) convertView
            .findViewById(R.id.age);
    holder.text5 = (TextView) convertView
            .findViewById(R.id.gender);
    holder.text6 = (TextView) convertView
            .findViewById(R.id.wardno);
    holder.text7 = (TextView) convertView
            .findViewById(R.id.roomno);
    holder.text8 = (TextView) convertView
            .findViewById(R.id.bedno);                  
    holder.btnList = (Button)convertView.findViewById(R.id.listbutton);
 //   holder.btnList.setOnClickListener(this);

    holder.btnList.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {                       
            Intent next=new Intent(context, SeviceDetails.class);
            context.startActivity(next);
        }
    });


    convertView.setTag(holder);
} else {
    holder = (ViewHolder) convertView.getTag();
}

holder.text1.setText(CountriesList.name[position]);
holder.text2.setText(CountriesList.mrn[position]);
holder.text3.setText(CountriesList.actualstart[position]);
holder.text4.setText(CountriesList.age[position]);
holder.text5.setText(CountriesList.gender[position]);
holder.text6.setText(CountriesList.wardNo[position]);
holder.text7.setText(CountriesList.roomNo[position]);
holder.text8.setText(CountriesList.bedNo[position]);

return convertView;
     }
     static class ViewHolder {
public Button btnList;
public TextView text8;
public TextView text7;
public TextView text6;
public TextView text5;
public TextView text4;
public TextView text1;
public TextView text2;
public TextView text3;
     }

  @Override
     public void notifyDataSetChanged()
  {
super.notifyDataSetChanged();
      }


    }

Answer 1

这是ListView中字母表索引的简单代码，它使用了2个java程序文件

1.我们处理listview索引的MainActivity文件

2.CustomAdapter.java 文件，它是 BaseAdapter 的子类，用于列出元素。

MainActivity.java

public class MainActivity extends Activity implements View.OnClickListener
{
    private Map<String, Integer> mapIndex;
    private String[] fruits;
    private ListView fruitsList;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        fruitsList.setAdapter(new CustomAdapter(this, Arrays.asList(fruits)));

        getIndexList(fruits);
        displayIndex();
    }

    private void init()
    {
        fruitsList = (ListView)findViewById(R.id.list_fruits);
        fruits = getResources().getStringArray(R.array.fruits_array);
        Arrays.sort(fruits);
    }

    private void getIndexList(String[] fruits)
    {
        mapIndex = new LinkedHashMap<String, Integer>();
        for(int i=0; i<fruits.length; i++)
        {
            String fruit = fruits[i];
            String index = fruit.substring(0,1);

            if(mapIndex.get(index) == null)
                mapIndex.put(index, i);
        }
    }

    private void displayIndex()
    {
        LinearLayout indexLayout = (LinearLayout)findViewById(R.id.side_index);
        List<String> indexList = new ArrayList<String>(mapIndex.keySet());

        TextView textView;
        for(String index : indexList)
        {
            textView = (TextView) getLayoutInflater().inflate(R.layout.alphabetindicator, null);
            textView.setText(index);
            textView.setOnClickListener(this);
            indexLayout.addView(textView);
        }
    }

    @Override
    public void onClick(View v) {
        TextView selectedTextView  = (TextView) v;
        fruitsList.setSelection(mapIndex.get(selectedTextView.getText()));
    }
}

CustomAdaper.java

public class CustomAdapter extends BaseAdapter
{
    private Context context;
    private List<String> listItem;
    private LayoutInflater layoutInflater;

    CustomAdapter(Context context, List<String> listItem) {
        this.context = context;
        this.listItem = listItem;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            viewHolder = new ViewHolder();
            layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = layoutInflater.inflate(R.layout.indexindicator, parent, false);
            viewHolder.textView = (TextView) convertView.findViewById(R.id.listitem);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }
        viewHolder.textView.setText(listItem.get(position));
        return convertView;
    }

    static class ViewHolder {
        TextView textView;
    }

    @Override
    public int getCount() {
        return listItem.size();
    }

    @Override
    public Object getItem(int position) {
        return listItem.get(position);
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }
}

activity_main.xml

<LinearLayout>
    <ListView
        android:id="@+id/list_fruits"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:scrollbars="none">
    </ListView>

    <LinearLayout
        android:id="@+id/side_index"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:background="@color/white"
        android:gravity="center_horizontal"
        android:orientation="vertical" >
    </LinearLayout>
</LinearLayout>

alphabetIndicator.xml

<?xml version="1.0" encoding="utf-8"?>
    <TextView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/side_list_item"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:padding="3dp"
        android:textSize="14sp" />

IndexIndicator.xml

<LinearLayout
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:orientation="vertical">
    <TextView
        android:id="@+id/listitem"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="left"
        android:padding="3dp"
        android:textColor="#000000"
        android:textSize="14sp" />
</LinearLayout>

最后，在 strings.xml 文件中包含一个字符串数组(根据您的需要替换/增加项目)

<string-array name="fruits_array">
        <item>Cantalope</item>
        <item>Date</item>
        <item>Grape</item>
        <item>Gooseberry</item>
        <item>Guava</item>
        <item>Honeydew melon</item>
        <item>Elderberry</item>
        <item>Fig</item>
        <item>Grapefruit</item>
</string-array>