显示android设备所以已安装App 可点击启动、搜索

 app名称*表示此app是系统应用，复制到项目后清单文件注册便可启动，此activity无需任何xml文件。

android 11系统以上清单需要配置以下权限：

<uses-permission android:name="android.permission.QUERY_ALL_PACKAGES" />
 

package com.apples.myapplication6;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.ComponentName;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Editable;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.TextWatcher;
import android.text.style.ForegroundColorSpan;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

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

public class AppListActivity2 extends Activity {

    private PackageManager packageManager;
    private List<ApplicationInfo> appInfoList;
    private List<ApplicationInfo> filteredAppList;
    private AppListAdapter adapter;
    @SuppressWarnings("all")
    private static View spaceView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        LinearLayout rootLayout = new LinearLayout(this);
        rootLayout.setLayoutParams(new ViewGroup.LayoutParams(-1, -1));
        rootLayout.setOrientation(LinearLayout.VERTICAL);

        LinearLayout headerLayout = new LinearLayout(this);
        headerLayout.setOrientation(LinearLayout.HORIZONTAL);
        LinearLayout.LayoutParams params3 = new LinearLayout.LayoutParams(-1, -2);
        rootLayout.addView(headerLayout, params3);

        final EditText searchEditText = new EditText(this);
        searchEditText.setHint("Search apps");
        searchEditText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                filterApps(s.toString());
            }

            @Override
            public void afterTextChanged(Editable s) {
            }
        });
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(0, -2, 2);
        headerLayout.addView(searchEditText, params);

        spaceView = new View(this);
        spaceView.setBackgroundColor(Color.parseColor("#F6F6F6"));
        spaceView.setOnClickListener(v -> {
            View view2 = AppListActivity2.this.getCurrentFocus();
            if (view2 != null) {
                InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                imm.hideSoftInputFromWindow(view2.getWindowToken(), 0);
            }
        });
        LinearLayout.LayoutParams params0 = new LinearLayout.LayoutParams(0, -1, 0.36f);
        headerLayout.addView(spaceView, params0);

        Button allBtn = new Button(this);
        allBtn.setText("App数量");
        allBtn.setOnClickListener(v -> {
            Toast.makeText(this, "列表共有：" + filteredAppList.size(), Toast.LENGTH_LONG).show();
        });
        LinearLayout.LayoutParams params4 = new LinearLayout.LayoutParams(0, -1, 0.5f);
        headerLayout.addView(allBtn, params4);

        Button refreshBtn = new Button(this);
        refreshBtn.setText("刷新");
        refreshBtn.setOnClickListener(v -> {
            spaceView.callOnClick();
            searchEditText.getText().clear();
            loadInstalledAppsAsync();
        });
        LinearLayout.LayoutParams params5 = new LinearLayout.LayoutParams(0, -1, 0.5f);
        headerLayout.addView(refreshBtn, params5);

        RecyclerView recyclerView = new RecyclerView(this);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        LinearLayout.LayoutParams params2 = new LinearLayout.LayoutParams(-1, -1);
        rootLayout.addView(recyclerView, params2);

        setContentView(rootLayout);

        packageManager = getPackageManager();
        appInfoList = new ArrayList<>();
        filteredAppList = new ArrayList<>();
        adapter = new AppListAdapter();
        recyclerView.setAdapter(adapter);

        loadInstalledAppsAsync();
    }

    @SuppressWarnings("all")
    private void filterApps(String query) {
        filteredAppList.clear();
        if (query.isEmpty()) {
            filteredAppList.addAll(appInfoList);
        } else {
            for (ApplicationInfo appInfo : appInfoList) {
                String appName = packageManager.getApplicationLabel(appInfo).toString().toLowerCase();
                String packageName = appInfo.packageName;
                if (appName.contains(query.toLowerCase()) || packageName.contains(query.toLowerCase())) {
                    filteredAppList.add(appInfo);
                }
            }
        }
        adapter.notifyDataSetChanged();
    }

    private void loadInstalledAppsAsync() {
        new LoadInstalledAppsTask().execute();
    }

    @SuppressWarnings("all")
    private class LoadInstalledAppsTask extends AsyncTask<Void, Void, List<ApplicationInfo>> {

        private ProgressDialog progressDialog;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            progressDialog = ProgressDialog.show(AppListActivity2.this, null, "加载中……");
            progressDialog.setCanceledOnTouchOutside(false);
            progressDialog.setCancelable(false);
        }

        @Override
        protected List<ApplicationInfo> doInBackground(Void... voids) {
            List<ApplicationInfo> installedApps = packageManager.getInstalledApplications(PackageManager.GET_META_DATA);
            List<ApplicationInfo> appList = new ArrayList<>();
            List<ApplicationInfo> systemAppList = new ArrayList<>();
            List<ApplicationInfo> userAppList = new ArrayList<>();
            String thatApp = AppListActivity2.this.getPackageName();
            ApplicationInfo tmpInfo = null;
            for (ApplicationInfo appInfo : installedApps) {
                if (thatApp.equals(appInfo.packageName)) {
                    tmpInfo = appInfo;
                    continue;
                }
                if (isSystemPackage(appInfo)) {
                    systemAppList.add(appInfo);
                } else {
                    userAppList.add(appInfo);
                }
            }
            Collections.sort(userAppList, new Comparator<ApplicationInfo>() {
                @Override
                public int compare(ApplicationInfo applicationInfo, ApplicationInfo t1) {
                    String aa = packageManager.getApplicationLabel(applicationInfo).toString();
                    String bb = packageManager.getApplicationLabel(t1).toString();
                    return aa.compareTo(bb);
                }
            });
            appList.addAll(userAppList);
            Collections.sort(systemAppList, new Comparator<ApplicationInfo>() {
                @Override
                public int compare(ApplicationInfo applicationInfo, ApplicationInfo t1) {
                    String aa = packageManager.getApplicationLabel(applicationInfo).toString();
                    String bb = packageManager.getApplicationLabel(t1).toString();
                    return aa.compareTo(bb);
                }
            });
            appList.addAll(systemAppList);
            appList.add(0, tmpInfo);
            return appList;
        }

        @Override
        protected void onPostExecute(List<ApplicationInfo> appList) {
            appInfoList.clear();
            appInfoList.addAll(appList);
            filteredAppList.clear();
            filteredAppList.addAll(appList);
            adapter.notifyDataSetChanged();
            progressDialog.dismiss();
        }
    }

    private boolean isSystemPackage(ApplicationInfo appInfo) {
        return (appInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
    }

    private class AppListAdapter extends RecyclerView.Adapter<AppViewHolder> {

        @NonNull
        @Override
        public AppViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            return new AppViewHolder(parent.getContext());
        }

        @Override
        public void onBindViewHolder(@NonNull AppViewHolder holder, int position) {
            ApplicationInfo appInfo = filteredAppList.get(position);
            String appName = packageManager.getApplicationLabel(appInfo).toString();
            String packageName = appInfo.packageName;
            boolean isSystemApp = isSystemPackage(appInfo);
            SpannableStringBuilder appNameBuilder = new SpannableStringBuilder(appName);
            if (isSystemApp) {
                int startIndex = appName.length();
                int endIndex = startIndex + 2;
                appNameBuilder.append(" *");
                appNameBuilder.setSpan(new ForegroundColorSpan(Color.RED),
                        startIndex, endIndex, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
            holder.bind(appInfo, appNameBuilder, packageName);
        }

        @Override
        public int getItemCount() {
            return filteredAppList.size();
        }
    }

    @SuppressWarnings("all")
    private static class AppViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        private ImageView appIconImage;
        private TextView appNameText;
        private TextView packageNameText;

        public AppViewHolder(@NonNull Context context) {
            super(createItemView(context));
            appIconImage = itemView.findViewWithTag("appIconImage");
            appNameText = itemView.findViewWithTag("appNameText");
            packageNameText = itemView.findViewWithTag("packageNameText");
            itemView.setOnClickListener(this);
        }

        private static View createItemView(Context context) {
            LinearLayout itemView = new LinearLayout(context);
            itemView.setLayoutParams(new ViewGroup.LayoutParams(-1, -2));
            itemView.setOrientation(LinearLayout.HORIZONTAL);
            itemView.setGravity(Gravity.CENTER_VERTICAL);
            itemView.setPadding(16, 16, 16, 16);
            itemView.setBackgroundResource(android.R.drawable.menuitem_background);

            ImageView appIconImage = new ImageView(context);
            appIconImage.setTag("appIconImage");
            appIconImage.setLayoutParams(new LinearLayout.LayoutParams(64, 64));
            appIconImage.setScaleType(ImageView.ScaleType.CENTER_CROP);
            itemView.addView(appIconImage);

            LinearLayout textContainer = new LinearLayout(context);
            textContainer.setOrientation(LinearLayout.VERTICAL);
            itemView.addView(textContainer);

            TextView appNameText = new TextView(context);
            appNameText.setTag("appNameText");
            appNameText.setTextSize(18);
            appNameText.setPadding(16, 0, 0, 0);
            textContainer.addView(appNameText);

            TextView packageNameText = new TextView(context);
            packageNameText.setTag("packageNameText");
            packageNameText.setPadding(16, 0, 0, 0);
            textContainer.addView(packageNameText);

            return itemView;
        }

        public void bind(ApplicationInfo appInfo, SpannableStringBuilder appName, String packageName) {
            appNameText.setText(appName);
            packageNameText.setText(packageName);
            new LoadAppIconTask(appIconImage).execute(appInfo);
        }

        @Override
        public void onClick(final View v) {
            spaceView.callOnClick();
            PackageManager packageManager = v.getContext().getPackageManager();
            String packageName = ((TextView) v.findViewWithTag("packageNameText")).getText().toString();
            if (packageName.equals(v.getContext().getPackageName())) return;
            try {
                Intent launcherIntent = new Intent(Intent.ACTION_MAIN);
                launcherIntent.addCategory(Intent.CATEGORY_LAUNCHER);
                launcherIntent.setPackage(packageName);
                final List<ResolveInfo> resolveInfos = packageManager.queryIntentActivities(launcherIntent, 0);
                if (resolveInfos.size() > 1) {
                    String[] acts = new String[resolveInfos.size()];
                    for (int i = 0; i < resolveInfos.size(); i++) {
                        ResolveInfo resolveInfo = resolveInfos.get(i);
                        ActivityInfo activityInfo = resolveInfo.activityInfo;
                        CharSequence label = resolveInfo.loadLabel(packageManager);
                        acts[i] = label + " >>> " + activityInfo.name;
                    }
                    Arrays.sort(acts);
                    new AlertDialog.Builder(v.getContext())
                            .setTitle("LAUNCHER Activity")
                            .setCancelable(false)
                            .setItems(acts, new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialogInterface, int i) {
                                    Intent intent = new Intent();
                                    ActivityInfo activityInfo = resolveInfos.get(i).activityInfo;
                                    intent.setComponent(new ComponentName(activityInfo.packageName, activityInfo.name));
                                    v.getContext().startActivity(intent);
                                }
                            })
                            .setNegativeButton("取消", null)
                            .create().show();
                } else {
                    Intent launchIntent = packageManager.getLaunchIntentForPackage(packageName);
                    if (launchIntent != null) {
                        v.getContext().startActivity(launchIntent);
                    } else {
                        Toast.makeText(v.getContext(), "没启动页面", Toast.LENGTH_SHORT).show();
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    @SuppressWarnings("all")
    private static class LoadAppIconTask extends AsyncTask<ApplicationInfo, Void, Drawable> {

        private final ImageView appIconImage;

        public LoadAppIconTask(ImageView appIconImage) {
            this.appIconImage = appIconImage;
        }

        @Override
        protected Drawable doInBackground(ApplicationInfo... appInfo) {
            PackageManager packageManager = appIconImage.getContext().getPackageManager();
            return appInfo[0].loadIcon(packageManager);
        }

        @Override
        protected void onPostExecute(Drawable drawable) {
            appIconImage.setImageDrawable(drawable);
        }
    }
}