频道管理难难

最新推荐文章于 2022-02-13 15:09:40 发布

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最新推荐文章于 2022-02-13 15:09:40 发布

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本文链接：https://blog.youkuaiyun.com/weixin_43218083/article/details/84311661

本文详细介绍了一种使用Android的RecyclerView实现频道管理功能的方法。通过自定义Adapter和ViewHolder，结合GridLayoutManagere实现频道的拖拽和切换效果，展示了如何在RecyclerView中处理不同类型的条目（已选频道、未选频道和标题），并提供了完整的代码实现。

导包：

 implementation 'com.android.support:recyclerview-v7:28.0.0'

main.xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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="match_parent"
    tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/contonts"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        ></android.support.v7.widget.RecyclerView>


</android.support.constraint.ConstraintLayout>

标题的xml:
title.xml:

<?xml version="1.0" encoding="utf-8"?>
<TextView
    android:id="@+id/text"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:paddingTop="8dp"
    android:paddingBottom="16dp"
    android:text="标题"
    android:textSize="18sp"
    />

选中的频道xml:
zhong.xml:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingLeft="4dp"
    android:paddingRight="4dp"
    android:paddingTop="4dp"
    android:paddingBottom="4dp"
    >
    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="频道名称"
        android:gravity="center"
        android:background="#ff6699"
        />

</FrameLayout>

未选中xml：
wei.xml:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingLeft="4dp"
    android:paddingRight="4dp"
    android:paddingTop="4dp"
    android:paddingBottom="4dp"
    >
    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="频道名称"
        android:gravity="center"
        android:background="#cccfff"
        />

</FrameLayout>

Bean类：

package guopuran.bwie.com.pindao;

public class Bean {
    //名称
    private String name;
    //是否选择的频道
    private boolean isSelected;
    //是否当前频道
    private boolean isCurrent;
    //是否固定不能更改的
    private boolean isFixted;

    public Bean(String name, boolean isSelected, boolean isCurrent) {
        this.name = name;
        this.isSelected = isSelected;
        this.isCurrent = isCurrent;
    }

    public String getName() {
        return name;
    }

    public boolean isSelected() {
        return isSelected;
    }

    public boolean isCurrent() {
        return isCurrent;
    }

    public boolean isFixted() {
        return isFixted;
    }

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

    public void setSelected(boolean selected) {
        isSelected = selected;
    }

    public void setCurrent(boolean current) {
        isCurrent = current;
    }

    public void setFixted(boolean fixted) {
        isFixted = fixted;
    }
}

适配器：
ContentsAdapter：

package guopuran.bwie.com.pindao;

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.TextView;

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

public class ContentsAdapter extends RecyclerView.Adapter<ContentsAdapter.ViewHolder> {
    private List<Bean> wei;
    private List<Bean> zhong;
    private Context context;

    public ContentsAdapter(Context context) {
        this.context = context;
        //初始化
        wei=new ArrayList<>();
        zhong=new ArrayList<>();
    }
    //输入
    public void setlist(List<Bean> wei,List<Bean> zhong) {
        this.wei = wei;
        this.zhong = zhong;
        //刷新适配器
        notifyDataSetChanged();
    }

    //当前position是否是选中的频道item
    public boolean iszhong(int position){
        return position<=zhong.size();
    }
    //当前position是否是标题
    public boolean isTitle(int position){
        return isweiTitle(position)||iszhongTitle(position);
    }
    //是否是选中的频道标题
    public boolean iszhongTitle(int position){
        return position==0;
}
    //是否是普通的标题
    public boolean isweiTitle(int position){
        return position==zhong.size()+1;
    }
    public Bean getItem(int position){
        if (isTitle(position)){
            return null;
        }
        if (iszhong(position)){
            return zhong.get(position-1);
        }
        return wei.get(position-zhong.size()-2);
    }
    //判断条目类型
    @Override
    public int getItemViewType(int position) {
        if (isTitle(position)){
            return R.layout.title;
        }else if (iszhong(position)){
            return R.layout.zhong;
        }
        return R.layout.wei;
    }
    //RecyclerView已经帮我们做好了复用
    //当没有复用的view,会调用这个方法。我们创建出ViewHolder
    //否则直接复用ViewHolder
    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        if (i==R.layout.title){
            return new ViewHolder(LayoutInflater.from(context).inflate(i,viewGroup,false));

        }else{
            return new ViewHolder(LayoutInflater.from(context).inflate(i,viewGroup,false),listener);

        }
    }
    //更新需要展示的View。即在这里做数据绑定
    @Override
    public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
        if (iszhongTitle(i)){
            viewHolder.text.setText("我的频道");
            return ;
        }else if (isweiTitle(i)){
            viewHolder.text.setText("频道管理");
            return;
        }
        viewHolder.text.setText(getItem(i).getName());
    }
    //需要展示多少条目
    @Override
    public int getItemCount() {
        //多两个标题
        return zhong.size()+wei.size()+2;

}
    private OnItemClickListener listener;
    public ContentsAdapter setOnItemClickListener(OnItemClickListener listener){
        this.listener=listener;
        return this;
    }
    //删除
    public Bean removeItem(int position){
        Bean bean=null;
        if (iszhong(position)){
            bean=zhong.remove(position-1);
        }else{
            bean=wei.remove(position-zhong.size()-2);
        }
        //通知
        //选中-1
        //未选中 -zhong.size()-2
        notifyItemRemoved(position);
        return bean;
    }
    public void addItem(Bean bean){
        if (bean.isSelected()){
            zhong.add(bean);
            notifyItemInserted(zhong.size());
        }else{
            wei.add(0,bean);
            notifyItemInserted(zhong.size()+2);
        }
    }
    //接口回调
    public interface OnItemClickListener{
        void OnItemClick(View itemView,int position);
    }

    class ViewHolder extends RecyclerView.ViewHolder{
        TextView text;
        public ViewHolder(View itemView){
            super(itemView);
            text=itemView.findViewById(R.id.text);
        }
        public ViewHolder(@NonNull View itemView, final OnItemClickListener listener) {

            this(itemView);
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (listener==null){
                        return;
                    }
                    listener.OnItemClick(ViewHolder.this.itemView,getAdapterPosition());
                }
            });
        }
    }
}

MainActivity：

package guopuran.bwie.com.pindao;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;

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

public class MainActivity extends AppCompatActivity {

    private RecyclerView contonts;
    private ContentsAdapter contentsAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取资源ID
        contonts = findViewById(R.id.contonts);
        //优化
        contonts.setHasFixedSize(true);
        //设置适配器
        contentsAdapter = new ContentsAdapter(this);
        //布局管理器
        GridLayoutManager layoutManager=new GridLayoutManager(this,4);
        //item如何跨列显示
        layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
            @Override
            public int getSpanSize(int i) {
                return contentsAdapter.isTitle(i)?4:1;
            }
        });
        //布局
        contonts.setLayoutManager(layoutManager);
        contonts.setAdapter(contentsAdapter);
        contentsAdapter.setOnItemClickListener(new ContentsAdapter.OnItemClickListener() {
            @Override
            public void OnItemClick(View itemView, int position) {
                //移除
                Bean bean=contentsAdapter.removeItem(position);
                bean.setSelected(!bean.isSelected());
                //添加
                contentsAdapter.addItem(bean);
            }
        });
        initData();
    }

    private void initData() {
        List<Bean> zhong=new ArrayList<>();
        List<Bean> wei=new ArrayList<>();

        zhong.add(new Bean("关注1",true,false));
        zhong.add(new Bean("关注2",true,false));
        zhong.add(new Bean("关注3",true,false));
        zhong.add(new Bean("关注4",true,false));
        zhong.add(new Bean("关注5",true,false));
        zhong.add(new Bean("关注6",true,false));
        zhong.add(new Bean("关注7",true,false));
        zhong.add(new Bean("关注8",true,false));

        wei.add(new Bean("关注9",false,false));
        wei.add(new Bean("关注10",false,false));
        wei.add(new Bean("关注11",false,false));
        wei.add(new Bean("关注12",false,false));
        wei.add(new Bean("关注13",false,false));
        wei.add(new Bean("关注14",false,false));
        wei.add(new Bean("关注15",false,false));
        wei.add(new Bean("关注16",false,false));
        wei.add(new Bean("关注17",false,false));
        wei.add(new Bean("关注18",false,false));

        contentsAdapter.setlist(wei,zhong);

    }
}

频道管理 难难

频道管理难难