相关疑难解决方法(0)

在我的应用程序中,我有这样的activity_main.xml: -

<Coordinator Layout>
   <AppBarLayout>
      <CollapsingToolbarLayout>
           <ImageView/>
           <Toolbar/>
       </CollapsingToolbarLayout>
   </AppBarLayout>
   <RecyclerView/>
</Coordinating Layout>

Layout.xml ----- >>>

<?xml version="1.0" encoding="utf-8"?>



<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/theme_background"
    android:id="@+id/drawerlayout"
    >


    <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        android:id="@+id/activity_main_id"
        tools:context="objectdistance.ajai.ram.sita.gallery.MainActivity">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/app_bar_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fitsSystemWindows="true"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">


            <android.support.design.widget.CollapsingToolbarLayout
                android:id="@+id/collapsing_toolbar"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_scrollFlags="scroll|exitUntilCollapsed"
                app:contentScrim="?attr/colorPrimary"
                app:expandedTitleMarginStart="48dp"
                app:expandedTitleMarginEnd="64dp"
                android:fitsSystemWindows="true">



                <ImageView
                    android:id="@+id/imagetoolbar"
                    android:layout_width="match_parent"
                    android:layout_height="200dp"
                    android:scaleType="centerCrop"
                    android:fitsSystemWindows="true"
                    android:foreground="@drawable/image_header_foreground"
                    app:layout_scrollFlags="scroll"
                    app:layout_collapseMode="parallax"/>

                <android.support.v7.widget.Toolbar
                    android:id="@+id/toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                    android:background="@drawable/theme_background"
                    app:layout_collapseMode="pin" >

                    <Spinner
                        android:id="@+id/spinner_nav"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"

                        android:dropDownVerticalOffset="?attr/actionBarSize" />

                </android.support.v7.widget.Toolbar>

            </android.support.design.widget.CollapsingToolbarLayout>


        </android.support.design.widget.AppBarLayout>




        <android.support.v7.widget.RecyclerView
            android:id="@+id/list" …

我已经看了很多教程,让ListView在侧面有字母(如联系人列表),但他们似乎都使用了ListActivity类和/或数据库中的数据,而我只是使用了ListView(没有特殊的Activity)和一个ArrayList的数据.有谁知道如何在我自己的ListView的联系人列表中实现该字母滚动功能？

再次编辑

我按照这个教程,我认为最终会使它工作,但我仍然被迫关闭.

class AlphabeticalAdapter extends ArrayAdapter<String> implements SectionIndexer
{
    private HashMap<String, Integer> alphaIndexer;
    private String[] sections;

    public AlphabeticalAdapter(Context c, int resource, List<String> data)
    {
        super(c, resource, data);
        for (int i = 0; i < data.size(); i++)
        {
            String s = data.get(i).substring(0, 1).toUpperCase();
            alphaIndexer.put(s, i);
        }

        Set<String> sectionLetters = alphaIndexer.keySet();
        ArrayList<String> sectionList = new ArrayList<String>(sectionLetters);
        Collections.sort(sectionList);
        sections = new String[sectionList.size()];
        sectionList.toArray(sections);

    }

    public int getPositionForSection(int section)
    {   
        return alphaIndexer.get(sections[section]);
    }

    public int getSectionForPosition(int position)
    {
        return 1;
    } …

package com.VRG;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import android.app.Activity;
import android.content.Context;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

public class Practice extends Activity {
    MediaPlayer mp;
    private Integer prac_sounds[] = { R.raw.cow, R.raw.camel, R.raw.dog,
            R.raw.donkey, R.raw.elephant, R.raw.horse, R.raw.lion, R.raw.rhino,
            R.raw.sheep, R.raw.wolf, R.raw.crow, R.raw.dove, R.raw.duck,
            R.raw.eagle, R.raw.owl, R.raw.parrot, R.raw.rooster, R.raw.cuckoo,
            R.raw.peocock, R.raw.sparrow };

    /** Called when the activity is first created. */

    // …