最近在写一个launcher，于是整理了一下获取应用的工具类和横向的显示所有app的方法。里面使用了横向的recyclerview来显示，内容也很简单。
结尾有源码的下载地址。

allapp.png

1.导入依赖

    implementation 'com.android.support:recyclerview-v7:27.1.1'

2.显示布局

注意：这里我使用了px的像素来适配屏幕，这个是适配的一种方式。
如果直接复制可能会报@dimen/x150找不到的错误。
这个在源码的valus里面可以找到。

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:background="#000000"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="@dimen/x150">
    </android.support.v7.widget.RecyclerView>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerviewtwo"
        android:layout_marginTop="@dimen/x20"
        android:layout_width="match_parent"
        android:layout_height="@dimen/x150">
    </android.support.v7.widget.RecyclerView>
</LinearLayout>

3.适配器

适配器里面的内容很普通，就是把获取到的值进行设置到布局里面。

package com.luo.recyclerviewallapp.adapter;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.luo.recyclerviewallapp.R;
import com.luo.recyclerviewallapp.bean.AppInfo;

import java.util.List;


/**
 * Created by luo on 2019/8/12.
 */

public class AllAdapter extends RecyclerView.Adapter<AllAdapter.VH> {

    private View mView;
    private List<AppInfo> mlist;
    private Context mContext;
    private VH mVH;
    private OnItemClickListener listener;
    private OnItemLongClickListener longClickListener;
    private AppInfo appInfo = null;

    public AllAdapter(Context context, List<AppInfo> list) {
        this.mlist = list;
        this.mContext = context;
    }

    @NonNull
    @Override
    public VH onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        mView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_allapp, parent, false);
        mVH = new VH(mView);
        return mVH;
    }

    @Override
    public void onBindViewHolder(@NonNull VH holder, int position) {
        appInfo = mlist.get(position);
        //获取到的app的图标和名字进行设置，也可以通过判断包名来修改图片
        holder.icon.setBackground(appInfo.getAppIcon());
        holder.name.setText(appInfo.getAppName());

        final int itemposition = position;
        holder.itemlayout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (listener != null) {
                    listener.onClick(itemposition);
                }
            }
        });
        holder.itemlayout.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                if (longClickListener != null) {
                    longClickListener.onClick(itemposition);
                }
                return true;
            }
        });
    }

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

    //点击接口
    public interface OnItemClickListener {
        void onClick(int position);
    }

    //公共的点击方法
    public void setOnItemClickListener(OnItemClickListener listener) {
        this.listener = listener;
    }

    //长按的点击接口
    public interface OnItemLongClickListener {
        void onClick(int position);
    }

    //公共的长按的接口
    public void setOnItemLongClickListener(OnItemLongClickListener longClickListener) {
        this.longClickListener = longClickListener;
    }

    public class VH extends RecyclerView.ViewHolder {

        public LinearLayout itemlayout;
        public TextView name;
        public ImageView icon;

        public VH(View itemView) {
            super(itemView);
            icon = (ImageView) itemView.findViewById(R.id.item_app_icon);
            itemlayout = (LinearLayout) itemView.findViewById(R.id.item_layout);
            name = (TextView) itemView.findViewById(R.id.item_app_name);
        }
    }
}

4.获取所有应用的工具类

package com.luo.recyclerviewallapp.utils;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.content.pm.ResolveInfo.DisplayNameComparator;

import com.luo.recyclerviewallapp.bean.AppInfo;

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

/**
 * Created by luo on 2019/8/12.
 */

public class AppUtils {

    /**
     * get all app info
     *
     * @param context
     * @return
     */
    public static final ArrayList<AppInfo> getAppInfos(Context context) {
        ArrayList<AppInfo> appInfos = new ArrayList<AppInfo>();
        PackageManager manager = context.getPackageManager();
        Intent mainIntent = new Intent("android.intent.action.MAIN", null);
        mainIntent.addCategory("android.intent.category.LAUNCHER");
        //通过查看是否有LAUNCHER属性来添加
        List<ResolveInfo> resolveInfos = manager.queryIntentActivities(mainIntent, 0);
        Collections.sort(resolveInfos, new DisplayNameComparator(manager));
        if (appInfos != null) {
            appInfos.clear();
            for (ResolveInfo resolveInfo : resolveInfos) {
                if (resolveInfo.activityInfo.packageName.equals("com.mstar.tv.tvplayer.ui")) {
                    continue;
                }
                //这里是过滤apk，可以加入一些你认为不需要显示的apk
                AppInfo appInfo = new AppInfo();
                appInfo.setAppIcon(resolveInfo.loadIcon(manager));
                appInfo.setAppName((String) resolveInfo.loadLabel(manager));
                appInfo.setPackageName(resolveInfo.activityInfo.packageName);
                appInfos.add(appInfo);
            }
        }
        return appInfos;
    }

}

5.bean文件

因为bean文件只是有一点，这里截图一下，有需要可以在源码中直接复制。

bean.png

6.MainActivit代码

package com.luo.recyclerviewallapp;

import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import com.luo.recyclerviewallapp.adapter.AllAdapter;
import com.luo.recyclerviewallapp.bean.AppInfo;
import com.luo.recyclerviewallapp.utils.AppUtils;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by luo on 2019/8/12.
 */


public class MainActivity extends AppCompatActivity {

    private List<AppInfo> allApp;
    private LinearLayoutManager linearLayoutManager;
    private LinearLayoutManager linearLayoutManagertwo;
    private AllAdapter allMyAdapater;
    private RecyclerView allAppRecycler;
    private RecyclerView allAppRecyclertwo;

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

    private void initData() {
        allApp = new ArrayList<AppInfo>();
        allApp = AppUtils.getAppInfos(this);
        allMyAdapater = new AllAdapter(this, allApp);
        linearLayoutManager = new LinearLayoutManager(this);
        linearLayoutManagertwo = new LinearLayoutManager(this);
    }

    private void initView() {
        allAppRecycler = (RecyclerView) findViewById(R.id.recyclerview);
        allAppRecyclertwo = (RecyclerView) findViewById(R.id.recyclerviewtwo);
        //把显示设置成横向，默认是竖列
        linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
        linearLayoutManagertwo.setOrientation(LinearLayoutManager.HORIZONTAL);

        allAppRecyclertwo.setLayoutManager(linearLayoutManagertwo);
        allAppRecyclertwo.setAdapter(allMyAdapater);

        allAppRecycler.setLayoutManager(linearLayoutManager);
        allAppRecycler.setAdapter(allMyAdapater);

        //点击跳转apk
        allMyAdapater.setOnItemClickListener(new AllAdapter.OnItemClickListener() {
            @Override
            public void onClick(int position) {
                //这里通过包名来跳转
                Intent mIntent = new Intent();
                PackageManager packageManager = getPackageManager();
                AppInfo appInfo = allApp.get(position);
                mIntent = packageManager.getLaunchIntentForPackage(appInfo.getPackageName());
                if (mIntent != null) {
                    startActivity(mIntent);
                }
            }
        });
         //长按卸载apk，但是我这里没有做刷新的操作，需要注意一下
        allMyAdapater.setOnItemLongClickListener(new AllAdapter.OnItemLongClickListener() {
            @Override
            public void onClick(int position) {
                AppInfo appInfo = allApp.get(position);
                uninstall(appInfo.getPackageName());
            }
        });
    }

    public boolean uninstall(String packageName) {
        boolean b = checkApplication(packageName);
        if (b) {
            Uri packageURI = Uri.parse("package:".concat(packageName));
            Intent intent = new Intent(Intent.ACTION_DELETE);
            intent.setData(packageURI);
            this.startActivity(intent);
            allMyAdapater.notifyDataSetChanged();
            return true;
        }
        return false;
    }

    private boolean checkApplication(String packageName) {
        if (packageName == null || "".equals(packageName)) {
            return false;
        }
        return true;
    }
}

7.整体思路

1.通过recyclerview的横向来显示布局
2.获取的时候通过LAUNCHER来得到apk
3.布局的焦点框是通过写一个白色矩形框来实现
4.跳转apk可以通过Adapter的点击事件来实现

总体来说，recyclerview来实现横向的显示，可以gridview的横向踩的坑少许多。

8.源码路径

https://github.com/githubsmallluo/RecyclerViewAllAPP/tree/master

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