RecyclerView增加和删除效果

学习导航

第一节：http://blog.csdn.net/bobo8945510/article/details/52823539 认识RecyclerView

第二节：http://blog.csdn.net/bobo8945510/article/details/52849084 RecyclerView分割线设置

第三节：http://blog.csdn.net/bobo8945510/article/details/52851558 RecyclerView布局靠左问题

四三节：http://blog.csdn.net/bobo8945510/article/details/52858500 RecyclerView实现监听

第五节：http://blog.csdn.net/bobo8945510/article/details/52860777 RecyclerView三种不同布局风格

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RecyclerView增加和删除效果,不多说，代码中有注释

这里用到的是 * recy_view.setItemAnimator(new DefaultItemAnimator());

一、代码目录结构

二、MainActivity中代码

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

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

public class MainActivity extends Activity implements View.OnClickListener{

    private RecyclerView recy_view;
    private List data;
    private ViewHoderAdaapters adaapters;
    private Button add_but,rm_but;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();



    }

    private void init() {
        add_but =  (Button) findViewById(R.id.add_but);
        add_but.setOnClickListener(this);
        rm_but =  (Button) findViewById(R.id.rm_but);
        rm_but.setOnClickListener(this);

        recy_view= (RecyclerView)findViewById(R.id.recy_view);
        //默认列表
        GridLayoutManager LM = new GridLayoutManager(this,4);
        //横向滑动
        recy_view.setLayoutManager(LM);
        recy_view.setItemAnimator(new DefaultItemAnimator());
        //样式二,对应类DividerItemDecoration02
        recy_view.addItemDecoration(new DividerItemDecoration02(this,LinearLayoutManager.HORIZONTAL,R.drawable.style02));

        initData();
        adaapters = new ViewHoderAdaapters(MainActivity.this,data);

        adaapters.setOnItemListener(new ViewHoderAdaapters.OnItemClickListener() {
            public void onLongClick(int position) {
                Toast.makeText(MainActivity.this,"您点击了第："+position+"个Item",Toast.LENGTH_SHORT).show();
            }
            public void onClick(int position) {
                Toast.makeText(MainActivity.this,"您点击了第："+position+"个Item",Toast.LENGTH_SHORT).show();
            }
        });
        recy_view.setAdapter(adaapters);
    }


    private void initData() {
        data = new ArrayList();
        for (int i=0; i < 20; i++) {
            data.add("我是熊大"+i);
        }
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.add_but:
                adaapters.addData(1);
                break;

            case R.id.rm_but:
                adaapters.removeData(1);
                break;
        }
    }
}

三、适配器代码中代码

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

import java.util.List;

/**
 * Created by ENZ on 2016/10/15.
 */
class ViewHoderAdaapters extends RecyclerView.Adapter {

    private Context context;
    private List datas;
    private LayoutInflater inflater;
    private OnItemClickListener mOnItemClickListener;

    //构造方法
    public ViewHoderAdaapters(MainActivity mainActivity, List data) {
        this.context = mainActivity;
        this.datas = data;
        inflater = LayoutInflater.from(context);
    }

    //定义一个监听接口，里面有两个方法
    public interface OnItemClickListener{
        void onClick(int position);
        void onLongClick(int position);
    }
    //给监听设置一个构造函数，用于main中调用
    public void setOnItemListener(OnItemClickListener mOnItemClickListener) {
        this.mOnItemClickListener = mOnItemClickListener;
    }

    @Override
    //重写onCreateViewHolder方法，返回一个自定义的ViewHolder
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.main_item,parent,false);
        ViewHoders viewHoders = new ViewHoders(view);
        return viewHoders;
    }
    @Override
    //填充onCreateViewHolder方法返回的holder中的控件
    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
        ((ViewHoders) holder).tv.setText(datas.get(position));

        if (mOnItemClickListener!=null) {
            //直接给某个空间添加监听
            ((ViewHoders) holder).li_layout.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mOnItemClickListener.onClick(position);
                }
            });
            //直接给某个空间添加长按监听
            ((ViewHoders) holder).li_layout.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mOnItemClickListener.onLongClick(position);
                }
            });
        }
    }
    @Override
    public int getItemCount() {
        return datas.size();
    }
    //自定义ViewHolder,
    /*
    * RecylerView封装了viewholder的回收复用，也就是说RecylerView标准化了ViewHolder，编写Adapter面向的是ViewHolder而不再是View了
    * */
    class ViewHoders extends RecyclerView.ViewHolder{
        private TextView tv;
        private LinearLayout li_layout;

        public ViewHoders(View itemView) {
            super(itemView);
            tv= (TextView) itemView.findViewById(R.id.textview);
            li_layout= (LinearLayout) itemView.findViewById(R.id.li_layout);
        }
    }
    //添加一个增加item数据的方法，posion代表你从主类中传过来的值，这个值对应你添加的item在列表中的位置
    public void addData(int position) {
        //保证列表没有数据时，首先添加
        if(datas.size()==0){
            datas.add(0, "我是熊大");
        }else {
            //更新列表
            datas.add(position, "我是熊大....");
            notifyItemInserted(position);
            notifyItemRangeChanged(position,datas.size());
        }
    }

    public void removeData(int position) {
        //保证列表有数据，并且最少有一条
        if(datas.size()<2&&datas.size()!=0){
            datas.remove(0);
            notifyDataSetChanged();
        }else if(datas.size()==0){//当列表没有数据提示用户，免得造成系统崩溃
            Toast.makeText(context,"搞毛啊，没数据了",Toast.LENGTH_SHORT).show();
        }else{//更新列表
            datas.remove(position);
            notifyDataSetChanged();
            notifyItemRemoved(position);
            notifyItemRangeChanged(position,datas.size());
        }

    }
}

---

四、分割线代码

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;

/**
 * Created by ENZ on 2016/10/15.
 */

public class DividerItemDecoration02 extends RecyclerView.ItemDecoration {
    //获取布局的方向
    public static final int HORIZONTAL = LinearLayoutManager.HORIZONTAL;

    public static final int VERTICAL = LinearLayoutManager.VERTICAL;


    //可以延长的
    private Drawable mDivider;

    private int mOrientation;


    //方向的判断
    private void setOrientation(int orientation) {
        if (orientation != HORIZONTAL && orientation != VERTICAL) {
            throw new IllegalArgumentException("你传递的方向参数好像有问题");
        }
        //方向赋值给对象mOrientation;
        mOrientation = orientation;
    }

    /**
     * 自定义分割线
     *
     * @param context
     * @param orientation 列表方向
     * @param drawableId  分割线图片
     */
    public DividerItemDecoration02(Context context, int orientation, int drawableId) {
        mDivider = ContextCompat.getDrawable(context, drawableId);
        setOrientation(orientation);
    }

    //重写onDraw（）方法。并且根据传递过来的方向来进行绘制分割线
    @Override
    public void onDraw(Canvas c, RecyclerView parent) {
        if (mOrientation == VERTICAL) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }
    }

    /**
     * 绘制横向 item 分割线
     * @param parent
     */
    private void drawHorizontal(Canvas c, RecyclerView parent) {
        //左右的间距 ，left就是距离父类边界的距离，right同理
        final int left = parent.getPaddingLeft()+10;
        final int right = parent.getWidth() - parent.getPaddingRight()-10;
        //获取item数据的长度
        final int childCount = parent.getChildCount();
        //循环绘制分割线
        for (int i = 0; i < childCount; i++) {
            //
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
    /**
     * 绘制纵向 item 分割线
     * @param parent
     */
    private void drawVertical(Canvas c, RecyclerView parent) {
        //左右的间距 ，top就是距离父类顶边界的距离，bottom是距离父类底部的边界距离
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();
        final int childCount = parent.getChildCount();
        //循环绘制分割线
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
    /*
    * 获取分割线尺寸
    * getItemOffsets 中为 outRect 设置的4个方向的值，将被计算进所有 decoration 的尺寸中，而这个尺寸，被计入了 RecyclerView 每个 item view 的 padding 中
    * */
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
        if (mOrientation == VERTICAL) {
            //在这个地方，我们才获取
            outRect.set(0, 0, 0,  mDivider.getIntrinsicWidth());
        }else{
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}

---

五、布局和样式代码

• main布局

?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_main"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/add_but"
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:layout_weight="1"
            android:text="添加一条新数据"/>
        <Button
            android:id="@+id/rm_but"
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:layout_weight="1"
            android:text="删除一条新数据"/>
    LinearLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recy_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
         />
LinearLayout>

• 效果图：
  

---

• item布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_main"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    <LinearLayout
        android:id="@+id/li_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:orientation="vertical">
        <TextView
            android:id="@+id/textview"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="我是熊大"/>

        <ImageView
            android:id="@+id/imgview"
            android:layout_width="80dp"
            android:layout_gravity="center_horizontal"
            android:layout_height="60dp"
            android:background="@drawable/xiong01"/>
    LinearLayout>
LinearLayout>

效果图：

---

• 样式

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

       
       <solid android:color="#ED9800"/>

      
      <size android:height="5dp" android:width="1dp"/>

shape>

六、demo:http://download.csdn.net/detail/bobo8945510/9658281