AS作业二

一、开发软件：Android studio

二、内容：

1、掌握UI设计中的layout布局（约束布局）与基本控件（button、text、imageview等）；

2、掌握复杂控件与adapter的使用；

3、对有recycleView的页面进行点击跳转设计；

要实现列表，在上次实验的基础上，选择在 fragment_weixin上添加 recyclerview。将原来的 TextView 删除，再添加一个 recyclerview

在 myadapter 中需要重写三个方法：

重写 onCreateViewHolder ：获取 view，并传入 MyViewHolder，最后返回一个 MyViewHolder

重写 onBindViewHolder ：设置 holder 中的数据

重写 getItemCount ：用于返回条目个数

添加 recyclerview 后，新建一个对应的 item_down.xml 文件，设计 recyclerview 内元素的 xml 样 式

创建适配器 RecyclerView.Adapter

完成适配器后，修改对应的 weixinFragment.java 文件

至此列表完成，接下来是进行跳转设计

在适配器里我们要加入点击监听事件，然后修改weixinFragment.java

在点击第一个事件时，会跳转到Main2Activity,点击其余事件则显示“在线”

然后写activity_main2.xml文件进行布局

在AndroidManifest.xml中添加

部分代码如下：

myadapter.java

package com.example.mywork;


import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.collection.CircularArray;
import androidx.recyclerview.widget.RecyclerView;

import java.util.List;


public class myadapter extends RecyclerView.Adapter {

    private static onRecyclerItemClickListener onItemClickListener;
    private List mList;
    private Context context;

    public myadapter(Context context,List list) {
        this.mList= list;
        this.context=context;
    }

    public myadapter() {

    }


    @NonNull
    @Override
    public Myviewholder onCreateViewHolder(@NonNull ViewGroup parent, int viewType){
        View view=(View)LayoutInflater.from(parent.getContext()).inflate(R.layout.item_down,parent,false);
        Myviewholder myviewholder= new Myviewholder((view));
        return myviewholder;
    }

    @Override
    public void onBindViewHolder(@NonNull Myviewholder holder, int position) {
        chat chat = mList.get(position);
        holder.Image.setImageResource(chat.getImageid());
        holder.Name.setText(chat.getName());
        holder.Message.setText(chat.getMessage());
//        holder.itemView.setonClickListener(new View.onClickListener() {
//            @Override
//            public void onClick(View v) {
//                Intent intent=new Intent(context,frdFragment.class);
//                context.startActivities(new Intent[]{intent});
//            }
//        });
    }

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

    public  class Myviewholder extends RecyclerView.ViewHolder{
        private ImageView Image;
        private TextView Name;
        private TextView Message;

        public Myviewholder(@NonNull View itemView) {
            super(itemView);
            Image = itemView.findViewById(R.id.item_img);
            Name = itemView.findViewById(R.id.item_name);
            Message = itemView.findViewById(R.id.item_message);
            itemView.setonClickListener(new View.onClickListener() {
                @Override
                public void onClick(View v) {
                    if(onItemClickListener!=null){
                        onItemClickListener.onRecyclerItemClick(getAdapterPosition());
                    }
                }
            });

        }
    }

    public static void setRecyclerItemClickListener(onRecyclerItemClickListener listener){
        onItemClickListener=listener;
    }
    public interface  OnRecyclerItemClickListener{
        void  onRecyclerItemClick(int position);
    }

}

weixinFragment.java

package com.example.mywork;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;

import android.app.Fragment;

import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Toast;

import androidx.recyclerview.widget.DividerItemDecoration;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

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


public class weixinFragment extends Fragment {
    private Context context;
    private List mList = new ArrayList();
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;


    public weixinFragment() {
        // Required empty public constructor
    }


    // TODO: Rename and change types and number of parameters
    public static weixinFragment newInstance(String param1, String param2) {
        weixinFragment fragment = new weixinFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view= inflater.inflate(R.layout.fragment_weixin, container, false);
        context = (Activity) view.getContext();
        InitData();
        RecyclerView recyclerView = view.findViewById(R.id.recyclerview);
        myadapter adapter = new myadapter(context,mList);
        recyclerView.setAdapter(adapter);
        LinearLayoutManager manager = new LinearLayoutManager(context);
        manager.setOrientation(LinearLayoutManager.VERTICAL);
        recyclerView.setLayoutManager(manager);
        recyclerView.addItemDecoration(new DividerItemDecoration(context,LinearLayoutManager.VERTICAL ));
        myadapter.setRecyclerItemClickListener(new myadapter.onRecyclerItemClickListener() {


            @Override
            public void onRecyclerItemClick(int position) {
                Toast.makeText(getActivity(),"在线",Toast.LENGTH_LONG).show();
                if (position==0){
                    Intent intent=new Intent(getActivity(),Main2Activity.class);
                    startActivity(intent);}

            }
        });
        return view;
    }

    private void InitData() {
        for (int i = 0; i < 10; i++) {
            chat friend_1 = new chat(i, R.drawable.friend_1, "刘婧","我们一起出去玩吧");
            mList.add(friend_1);
            chat friend_2= new chat(i, R.drawable.friend_2, "高妍","你想去看电影吗");
            mList.add(friend_2);
            chat friend_3 = new chat(i, R.drawable.friend_3, "占明润","可好看了");
            mList.add(friend_3);
            chat friend_4 = new chat(i, R.drawable.friend_4, "陈飞宇","哈哈哈哈笑死了");
            mList.add(friend_4);
            chat friend_5 = new chat(i, R.drawable.friend_5, "徐洲","冲冲冲");
            mList.add(friend_5);
            chat friend_6 = new chat(i, R.drawable.friend_6, "黄林海","哎哟");
            mList.add(friend_6);
            chat friend_7 = new chat(i, R.drawable.friend_7, "胡凯","那就行");
            mList.add(friend_7);
            chat friend_8 = new chat(i, R.drawable.friend_8, "陈聪颖","去打球吧");
            mList.add(friend_8);
            chat friend_9 = new chat(i, R.drawable.friend_9, "余畅","我也觉得");
            mList.add(friend_9);
            chat friend_10 = new chat(i, R.drawable.friend_10, "余梦珂","莫？");
            mList.add(friend_10);
        }
    }


}

activity_main2.xml

fragment_weixin.xml

item_dowm.xml

三、运行界面展示

 四、源码的代码仓库地址

代码仓库