FastScroll(2)不分组的listview 打开fastscroll的分组提示功能

本文只让fastscroll具有提示分组功能，但listview并不显示分组，如果想让分组的listview显示fastscroll，看下篇。

1，在listview中打开fastscroll

2，自定义fastscroll的样式，其中包括分组相关的样式

3，代码如下：

主要是实现了sectionIndexer接口

 import java.util.ArrayList;

 import android.content.Context;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
 import android.widget.ImageView;
 import android.widget.SectionIndexer;
 import android.widget.TextView;

 import com.example.fastscroll.R;

 public class CustomFastScrollAdapter extends BaseAdapter implements SectionIndexer{

     private LayoutInflater mInflater;
     private Context mContext;

     /*
      * 保存当前section的第一条记录的Position
      * Character是section,Integer是section对应的第一条数据的position
      */
     /*
      *     保存每个section的第一条数据的position
      *     firstPositions的下标        firstPositions的值
      *                 0                0
      *                 1                2
      *                 2                4
      *              3                6
      */

     private Integer firstPositions[];

     /*     用空间代时间，把数据中的每个position对应的section index存下来
      *     如：
      *     sectionIndexes的下标        sectionIndexes数组中的值（section的下标）
      *             0                          0
      *             1                        0
      *             2                        1
      *             3                        1
      *             4                        2
      *             5                        2
      *             6                        3
      *             ...                        ...
      */
     private int sectionIndexes[];//保存每个position对应的section index

     private Character sections [] ;
     private String countries[]= { "Afghanistan", "Albania", "Algeria", "American Samoa",
             "Andorra", "Angola", "Anguilla", "Antarctica",
             "Antigua and Barbuda", "Argentina", "Armenia", "Aruba",
             "Australia", "Austria", "Azerbaijan",
             "Bahrain", "Bangladesh","Barbados", "Belarus", "Belgium",
             "Belize", "Benin", "Bermuda","Bhutan", "Bolivia",
             "Bosnia and Herzegovina", "Botswana","Bouvet Island",
             "Brazil", "British Indian Ocean Territory","British Virgin Islands",
             "Brunei", "Bulgaria", "Burkina Faso","Burundi", "Cote d'Ivoire",
             "Cambodia", "Cameroon", "Canada","Cape Verde",
             "Cayman Islands", "Central African Republic", "Chad",
             "Chile", "China", "Christmas Island", "Cocos (Keeling) Islands",
             "Colombia", "Comoros", "Congo", "Cook Islands", "Costa Rica",
             "Croatia", "Cuba", "Cyprus", "Czech Republic",
             "Democratic Republic of the Congo", "Denmark", "Djibouti",
             "Dominica", "Dominican Republic",
             "East Timor", "Ecuador", "Egypt",
             "El Salvador", "Equatorial Guinea", "Eritrea", "Estonia","Ethiopia",
             "Faeroe Islands", "Falkland Islands", "Fiji",
             "Finland", "Former Yugoslav Republic of Macedonia", "France",
             "French Guiana", "French Polynesia", "French Southern Territories",
             "Gabon", "Georgia", "Germany", "Ghana", "Gibraltar", "Greece",
             "Greenland", "Grenada", "Guadeloupe", "Guam", "Guatemala",
             "Guinea", "Guinea-Bissau", "Guyana",
             "Haiti","Heard Island and McDonald Islands", "Honduras", "Hong Kong","Hungary",
             "Iceland", "India", "Indonesia", "Iran", "Iraq","Ireland", "Israel","Italy",
             "Jamaica", "Japan", "Jordan",
             "Kazakhstan", "Kenya", "Kiribati", "Kuwait", "Kyrgyzstan", "Laos",
             "Latvia", "Lebanon", "Lesotho", "Liberia", "Libya",
             "Liechtenstein", "Lithuania", "Luxembourg", "Macau", "Madagascar",
             "Malawi", "Malaysia", "Maldives", "Mali", "Malta",
             "Marshall Islands", "Martinique", "Mauritania", "Mauritius",
             "Mayotte", "Mexico", "Micronesia", "Moldova", "Monaco", "Mongolia",
             "Montserrat", "Morocco", "Mozambique", "Myanmar", "Namibia",
             "Nauru", "Nepal", "Netherlands", "Netherlands Antilles",
             "New Caledonia", "New Zealand", "Nicaragua", "Niger", "Nigeria",
             "Niue", "Norfolk Island", "North Korea", "Northern Marianas",
             "Norway", "Oman", "Pakistan", "Palau", "Panama",
             "Papua New Guinea", "Paraguay", "Peru", "Philippines",
             "Pitcairn Islands", "Poland", "Portugal", "Puerto Rico", "Qatar",
             "Reunion", "Romania", "Russia", "Rwanda", "Sqo Tome and Principe",
             "Saint Helena", "Saint Kitts and Nevis", "Saint Lucia",
             "Saint Pierre and Miquelon", "Saint Vincent and the Grenadines",
             "Samoa", "San Marino", "Saudi Arabia", "Senegal", "Seychelles",
             "Sierra Leone", "Singapore", "Slovakia", "Slovenia",
             "Solomon Islands", "Somalia", "South Africa",
             "South Georgia and the South Sandwich Islands", "South Korea",
             "Spain", "Sri Lanka", "Sudan", "Suriname",
             "Svalbard and Jan Mayen", "Swaziland", "Sweden", "Switzerland",
             "Syria", "Taiwan", "Tajikistan", "Tanzania", "Thailand",
             "The Bahamas", "The Gambia", "Togo", "Tokelau", "Tonga",
             "Trinidad and Tobago", "Tunisia", "Turkey", "Turkmenistan",
             "Turks and Caicos Islands", "Tuvalu", "Uganda",
             "Ukraine", "United Arab Emirates", "United Kingdom",
             "United States", "United States Minor Outlying Islands", "Uruguay",
             "Uzbekistan", "Vanuatu", "Vatican City", "Venezuela", "Vietnam","Virgin Islands",
             "Wallis and Futuna", "Western Sahara", "Yemen", "Yugoslavia",
             "Zambia", "Zimbabwe" };
     /*private String countries[]= {
             "A",
             "啊有", "啊有2", "啊1有",
             "啊有3", "爱有3", "爱有4", "暗3","暗32",
             "B",
             "把工和1", "把工2和","把1工和", "把工2和", "把工4和",
             "白2为", "冰的","冰的2", "冰的3","布是","部公","爸五","兵妥",
             "兵妥2","兵妥3","兵妥4",
             "C",
             "草莓", "参数", "次国粗", "操类1", "操类2", "操类3", "操类4", "操类5", "操类6",
             "操类7","粗3","粗33","粗34","粗35","粗36",
             "D",
             "吊炮","灯具","都产遥","顶为","大有","端人在","电中工","到这要","当遥1",
             "当遥2","当遥3","当遥4","当遥5"
             };*/

     @Override
     public int getCount() {
         return countries.length;
     }

     @Override
     public Object getItem(int position) {
         return countries[position];
     }

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

     @Override
     public View getView(int position, View convertView, ViewGroup parent) {
         if (convertView == null) {
             convertView = mInflater.inflate(R.layout.list_item_custom_fs, parent,false);
         }
         ImageView icon = (ImageView) convertView.findViewById(R.id.iv_icon);
         icon.setImageResource(R.drawable.list_item_custom_fs_icon);
         TextView content = (TextView) convertView.findViewById(R.id.tv_content);

         content.setText(countries[position]);

         return convertView;
     }

     public CustomFastScrollAdapter(Context ctxt){
         mContext = ctxt;
         mInflater = LayoutInflater.from(mContext);

         //假设countries已经排序,本例中确实已经排序
         //把section对应的第一条数据的position存下来
         ArrayList<Integer> tmpFirstPositions = new ArrayList<Integer>();
         ArrayList<Character> tmpSections = new ArrayList<Character>();
         sectionIndexes = new int[countries.length];
         char lastChar = '\0';
         int index = -;
         for (int i = ; i < countries.length; i++) {
             String country = countries[i];
             char ch = country.charAt();
             if (ch != lastChar) {
                 //只存第一条数据的position,其它的跳过。
                 tmpSections.add(ch);//增加一个section
                 tmpFirstPositions.add(i);//增加该section的第一条记录的位置
                 ++index;
             }
             lastChar = ch;
             sectionIndexes[i] = index;
         }
         sections = new Character[tmpSections.size()];
         tmpSections.toArray(sections);

         firstPositions = new Integer[tmpFirstPositions.size()];
         tmpFirstPositions.toArray(firstPositions);

     }
     //返回分组数组，分组是用来显示预览的(它是内部分的)。如果分组中数据是string 那么直接显示它，如果是object，将调用其中的toString函数
     @Override
     public Object[] getSections() {
         return sections;
     }
     //根据section的index返回在该section在整个数据中的首个index
     @Override
     public int getPositionForSection(int sectionIndex) {
         sectionIndex %= sections.length;
         return firstPositions[sectionIndex];
     }
     //根据数据的index返回所属section的index
     @Override
     public int getSectionForPosition(int position) {
         return sectionIndexes[position];
     }
 }

 import android.app.Fragment;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ListView;

 import com.example.fastscroll.R;

 public class CustomFastScrollFrgmt extends Fragment {
     private ListView mListView;
     private CustomFastScrollAdapter mAdapter;

     void init(){
         mAdapter = new CustomFastScrollAdapter(getActivity());
         mListView.setAdapter(mAdapter);
     }
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
             Bundle savedInstanceState) {
         View v = inflater.inflate(R.layout.frgmt_custom_fastscroll, container,false);
         mListView = (ListView) v.findViewById(R.id.list_custom_fs);
         init();

         return v;
     }
 }

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context="${relativePackage}.${activityClass}" >

      <ListView
         android:id="@+id/list_custom_fs"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:fastScrollEnabled="true" />

         <!-- android:fastScrollAlwaysVisible="true" -->

 </LinearLayout>

 　　<style name="CustomFastScrollTheme" parent="AppBaseTheme">
         <!-- api21 -->
         <!-- <item name="android:fastScrollStyle">@style/CustomFastScrollTheme</item> -->

         <item name="android:fastScrollThumbDrawable">@drawable/fastscroll_thumb_aje</item>
         <item name="android:fastScrollOverlayPosition">atThumb</item>
         <item name="android:fastScrollTextColor">#DA4A38</item>
         <!-- <item name="android:fastScrollTrackDrawable">@drawable/us</item> -->
         <item name="android:fastScrollPreviewBackgroundRight">@drawable/fastscroll_preview_right</item>
     </style>