android获取应用包名，按照首字母排序，支持字幕条索引完整实现代码

以下是获取应用包名并按照首字母排序，支持字母索引的完整代码：

import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.text.TextUtils;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AlphabetIndexer;
import android.widget.ListView;
import android.widget.SectionIndexer;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private Context mContext;
    private ListView mListView;
    private TextView mIndexTv;
    private SideBar mSideBar;
    private List<AppInfo> mAppInfoList;
    private AppAdapter mAppAdapter;
    private Handler mHandler;
    private SectionIndexer mIndexer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mContext = this;

        mListView = findViewById(R.id.list_view);
        mIndexTv = findViewById(R.id.index_tv);
        mSideBar = findViewById(R.id.side_bar);

        mHandler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                if (msg.what == 0) {
                    mIndexer = new AlphabetIndexer(new AppCursorWrapper(mAppInfoList), 0, "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
                    mAppAdapter = new AppAdapter(mContext, mAppInfoList, mIndexer);
                    mListView.setAdapter(mAppAdapter);
                }
            }
        };

        new Thread(new Runnable() {
            @Override
            public void run() {
                mAppInfoList = getInstalledApps();
                Collections.sort(mAppInfoList, new Comparator<AppInfo>() {
                    @Override
                    public int compare(AppInfo a1, AppInfo a2) {
                        return a1.getPinyin().compareTo(a2.getPinyin());
                    }
                });
                mHandler.sendEmptyMessage(0);
            }
        }).start();

        mSideBar.setOnTouchingLetterChangedListener(new SideBar.OnTouchingLetterChangedListener() {
            @Override
            public void onTouchingLetterChanged(String letter) {
                int position = mIndexer.getPositionForSection(letter.charAt(0));
                if (position != -1) {
                    mListView.setSelection(position);
                }
                mIndexTv.setText(letter);
                mIndexTv.setVisibility(View.VISIBLE);
                mHandler.removeCallbacksAndMessages(null);
                mHandler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        mIndexTv.setVisibility(View.GONE);
                    }
                }, 1000);
            }
        });

        mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                // do something
            }
        });
    }

    private List<AppInfo> getInstalledApps() {
        List<AppInfo> list = new ArrayList<>();
        PackageManager pm = mContext.getPackageManager();
        List<ApplicationInfo> installedApps = pm.getInstalledApplications(0);
        for (ApplicationInfo appInfo : installedApps) {
            if ((appInfo.flags & ApplicationInfo.FLAG_SYSTEM) == 0) {
                AppInfo info = new AppInfo();
                info.setName(appInfo.loadLabel(pm).toString());
                info.setPackageName(appInfo.packageName);
                info.setPinyin(PinyinUtils.getPinyin(info.getName()));
                list.add(info);
            }
        }
        return list;
    }

    private static class AppInfo {
        private String name;
        private String packageName;
        private String pinyin;

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getPackageName() {
            return packageName;
        }

        public void setPackageName(String packageName) {
            this.packageName = packageName;
        }

        public String getPinyin() {
            return pinyin;
        }

        public void setPinyin(String pinyin) {
            this.pinyin = pinyin;
        }
    }
}

其中，`getInstalledApps`方法用于获取已安装应用列表，`AppInfo`类用于存储应用信息，`PinyinUtils`类用于将中文转换为拼音。这里使用了第三方库`AlphabetIndexer`来实现字母索引。