团队项目-第一阶段冲刺-5

一、说在前面

1、昨天完成了：

1）脱离对现成的api的依赖，自己独立爬取、处理和存储数据，实现数据初步审核去除“坏数据”。

2）在web端，自己编写自己的“api”接口，灵活的组织和传递自己所需的数据。

3）重构前三天的代码，加强了app的稳定性，（比如说：现成的api接口用个别的图片地址形式和其他大多数不同，按照统一的方法进行渲染时会出现系统崩溃的现象）。

4）新闻类别数据项展示时换用了卡片视图，是界面更加美观。

2、今天完成了：

1）历史记录的增删，展示。

3、明天的计划：

1）用户发布自己的新闻。（6h）

二、冲刺成果

可滑动删除：

三、代码

1、实体

package com.me.domain;

import androidx.room.ColumnInfo;
import androidx.room.Entity;
import androidx.room.PrimaryKey;

@Entity
public class New_ {
    @PrimaryKey(autoGenerate = true)
    private int id;
//    @ColumnInfo(name = "评论数量")
    private int commentCount;
//    @ColumnInfo(name = "阅读量")
    private int priority;
//    @ColumnInfo(name = "来源")
    private String source;
//    @ColumnInfo(name = "标题")
    private String title;
//    @ColumnInfo(name = "摘要")
    private String digest;
//    @ColumnInfo(name = "图片地址")
    private String imgsrc;
//    @ColumnInfo(name = "时间")
    private String ptime;
//    @ColumnInfo(name = "正文")
    private String zw;
//    @ColumnInfo(name = "类型")
    private String type;
    private Boolean history = false;


    public Boolean getHistory() {
        return history;
    }

    public void setHistory(Boolean history) {
        this.history = history;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public int getCommentCount() {
        return commentCount;
    }

    public void setCommentCount(int commentCount) {
        this.commentCount = commentCount;
    }

    public int getPriority() {
        return priority;
    }

    public void setPriority(int priority) {
        this.priority = priority;
    }

    public String getSource() {
        return source;
    }

    public void setSource(String source) {
        this.source = source;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDigest() {
        return digest;
    }

    public void setDigest(String digest) {
        this.digest = digest;
    }

    public String getImgsrc() {
        return imgsrc;
    }

    public void setImgsrc(String imgsrc) {
        this.imgsrc = imgsrc;
    }

    public String getPtime() {
        return ptime;
    }

    public void setPtime(String ptime) {
        this.ptime = ptime;
    }

    public String getZw() {
        return zw;
    }

    public void setZw(String zw) {
        this.zw = zw;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }
}

View Code

2、dao层（接口+注解）

package com.me.dao;

import androidx.lifecycle.LiveData;
import androidx.room.Dao;
import androidx.room.Delete;
import androidx.room.Insert;
import androidx.room.Query;

import com.me.domain.New_;

import java.util.List;

@Dao
public interface NewsDao {
    @Insert
    void insertNews(New_... new_s);

    @Delete
    void deleteNews(New_... new_);

    @Query("DELETE FROM New_")
    void deleteAllNews();

    @Query("SELECT * FROM New_ ORDER BY ID DESC")
    LiveData<List<New_>> getAllNew_sLive();

}

View Code

3、database：

package com.me.db;

import android.content.Context;

import androidx.room.Database;
import androidx.room.Room;
import androidx.room.RoomDatabase;

import com.me.dao.NewsDao;
import com.me.domain.New_;

@Database(entities = {New_.class},version = 1,exportSchema = false)
public abstract class NewsDatabase extends RoomDatabase {
    private static NewsDatabase INSTANCE;
    public static synchronized NewsDatabase getNewsDatabase(Context context){
        if( INSTANCE == null){
            INSTANCE = Room.databaseBuilder(context.getApplicationContext(), NewsDatabase.class,"news_database")
                    //.addMigrations(MIGRATION_1_2)
                    .build();
        }
        return INSTANCE;
    }

    public abstract NewsDao getNewsDao();
}

View Code

4、ui界面

1）数据项：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
    android:orientation="vertical">

    <androidx.cardview.widget.CardView
        android:layout_marginTop="3dp"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <com.me.view.MyImageView
                android:id="@+id/iv_new"
                android:layout_width="0dp"
                android:layout_height="80dp"
                android:layout_margin="4dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toStartOf="@+id/guideline"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

            <androidx.constraintlayout.widget.Guideline
                android:id="@+id/guideline"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                app:layout_constraintGuide_percent="0.2" />

            <LinearLayout
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:gravity="center"
                android:orientation="vertical"
                android:padding="4dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="@+id/guideline"
                app:layout_constraintTop_toTopOf="parent">>

                <TextView
                    android:id="@+id/tv_title"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:maxLines="1"
                    android:text="title"
                    android:textSize="24dp" />

                <TextView
                    android:id="@+id/tv_content"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:maxLines="3"
                    android:text="content"
                    android:textSize="13dp" />

                <TextView
                    android:id="@+id/tv_date"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginRight="5dp"
                    android:gravity="right"
                    android:text="content"
                    android:textSize="10dp" />
            </LinearLayout>

        </androidx.constraintlayout.widget.ConstraintLayout>
    </androidx.cardview.widget.CardView>
</LinearLayout>

View Code

2）历史数据界面：

<FrameLayout 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"
    tools:context="com.me.fragment.HistoryFragment">


    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/history"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</FrameLayout>

View Code

5、逻辑代码（fragment）

package com.me.fragment;


import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.LiveData;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProviders;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.me.ViewModel.NewsViewModel;
import com.me.adapter.NewAdapter;
import com.me.domain.New_;
import com.me.domain.News;
import com.me.news_2.R;

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

/**
 * A simple {@link Fragment} subclass.
 */
public class HistoryFragment extends Fragment {
    private NewAdapter adapter = new NewAdapter();
    private RecyclerView recyclerView;
    private NewsViewModel newsViewModel;
    private List<News> list = new ArrayList<News>();
    private List<New_> list_ = new ArrayList<New_>();

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


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View inflate = inflater.inflate(R.layout.fragment_history, container, false);
        recyclerView = inflate.findViewById(R.id.history);
        return inflate;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        newsViewModel = ViewModelProviders.of(this).get(NewsViewModel.class);
        final LiveData<List<New_>> allNews = newsViewModel.getAllNews();
        allNews.observe(requireActivity(), new Observer<List<New_>>() {
            @Override
            public void onChanged(List<New_> new_s) {
                list_ = new_s;
                Gson gson = new Gson();
                String s = gson.toJson(new_s);
                list = gson.fromJson(s,new TypeToken<List<News>>(){}.getType());
                adapter.setData(list);
                adapter.notifyDataSetChanged();
            }
        });
//        Toast.makeText(getContext(), allNews.isEmpty()+"   ", Toast.LENGTH_SHORT).show();

        recyclerView.setAdapter(adapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
        recyclerView.setAdapter(adapter);

        new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(0,ItemTouchHelper.START | ItemTouchHelper.END) {
            @Override
            public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
//                New_ new_ = list_.get(viewHolder.getLayoutPosition());
//                newsViewModel.deleteNews(new_);
                return false;
            }

            @Override
            public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
                New_ new_ = list_.get(viewHolder.getLayoutPosition());
                newsViewModel.deleteNews(new_);
            }
        }).attachToRecyclerView(recyclerView);

    }
}

View Code

6、适配器：

package com.me.fragment;


import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.LiveData;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProviders;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.me.ViewModel.NewsViewModel;
import com.me.adapter.NewAdapter;
import com.me.domain.New_;
import com.me.domain.News;
import com.me.news_2.R;

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

/**
 * A simple {@link Fragment} subclass.
 */
public class HistoryFragment extends Fragment {
    private NewAdapter adapter = new NewAdapter();
    private RecyclerView recyclerView;
    private NewsViewModel newsViewModel;
    private List<News> list = new ArrayList<News>();
    private List<New_> list_ = new ArrayList<New_>();

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


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View inflate = inflater.inflate(R.layout.fragment_history, container, false);
        recyclerView = inflate.findViewById(R.id.history);
        return inflate;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        newsViewModel = ViewModelProviders.of(this).get(NewsViewModel.class);
        final LiveData<List<New_>> allNews = newsViewModel.getAllNews();
        allNews.observe(requireActivity(), new Observer<List<New_>>() {
            @Override
            public void onChanged(List<New_> new_s) {
                list_ = new_s;
                Gson gson = new Gson();
                String s = gson.toJson(new_s);
                list = gson.fromJson(s,new TypeToken<List<News>>(){}.getType());
                adapter.setData(list);
                adapter.notifyDataSetChanged();
            }
        });
//        Toast.makeText(getContext(), allNews.isEmpty()+"   ", Toast.LENGTH_SHORT).show();

        recyclerView.setAdapter(adapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
        recyclerView.setAdapter(adapter);

        new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(0,ItemTouchHelper.START | ItemTouchHelper.END) {
            @Override
            public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
//                New_ new_ = list_.get(viewHolder.getLayoutPosition());
//                newsViewModel.deleteNews(new_);
                return false;
            }

            @Override
            public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
                New_ new_ = list_.get(viewHolder.getLayoutPosition());
                newsViewModel.deleteNews(new_);
            }
        }).attachToRecyclerView(recyclerView);

    }
}

View Code

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原文地址：https://www.cnblogs.com/20183544-wangzhengshuai/p/12732403.html