RecyclerView 使用全体验

RecyclerView是谷歌support-V7包下新增的控件,用来替代ListView的使用,在RecyclerView标准化了ViewHolder类似于ListView中convertView用来做视图缓存

体验流程：

设置布局管理器（layoutManager）以控制Item的布局方式 <垂直水平ListView，垂直水平GridView，瀑布流>
设置Item的间隔样式
设置Item删除和添加的动画
实现Item的点击和长按事件

app/build.gradle

implementation 'com.android.support:appcompat-v7:25.3.1'
implementation 'com.android.support:recyclerview-v7:25.3.1'

RecyclerViewActivity.java

package com.example.testnewas.activity;

import android.support.v7.app.AppCompatActivity;
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.support.v7.widget.StaggeredGridLayoutManager;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import com.example.testnewas.R;
import com.example.testnewas.adapters.Radapter;
import com.example.testnewas.views.DividerGridItemDecoration;
import com.example.testnewas.views.MyDividerItemDecoration;

import java.util.ArrayList;

public class RActivity extends AppCompatActivity implements View.OnClickListener{

    private RecyclerView recyclerView;
    private Radapter adapter;
    private RecyclerView.LayoutManager layoutManager;

    private TextView addItem;
    private TextView deleteItem;

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

    private void initView() {
        recyclerView = (RecyclerView) findViewById(R.id.my_recycle_view);
        recyclerView.setAdapter(adapter);
        //设置布局管理器以控制Item的布局方式，横向、竖向以及瀑布流方式。
        recyclerView.setLayoutManager(layoutManager);
        //间隔线样式
//        recyclerView.addItemDecoration(new MyDividerItemDecoration(this, MyDividerItemDecoration.VERTICAL_LIST));
        recyclerView.addItemDecoration(new DividerGridItemDecoration(this));
        //默认的Item删除和添加的动画
        recyclerView.setItemAnimator(new DefaultItemAnimator());

        addItem = (TextView) findViewById(R.id.add_item);
        deleteItem = (TextView) findViewById(R.id.delete_item);
        addItem.setOnClickListener(this);
        deleteItem.setOnClickListener(this);
    }

    private void initConfig() {
        adapter = new Radapter(initData());
        //Item点击事件
        adapter.setOnItemClickListener(new Radapter.OnItemClickListener() {
            @Override
            public void onClick(int position) {
                Toast.makeText(RActivity.this, "click " + position + " item", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onLongClick(int position) {
                Toast.makeText(RActivity.this, "long click " + position + " item", Toast.LENGTH_SHORT).show();

//长按删除当前item

adapter.deleteItem(position);
            }
        });
        //垂直水平线性列表ListView
//        layoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
        //垂直滚动GridView(每行4)
//        layoutManager = new GridLayoutManager(this, 4);
        //水平滚动GridView(每列4)
//        layoutManager = new StaggeredGridLayoutManager(4, StaggeredGridLayoutManager.HORIZONTAL);
        //瀑布流
        layoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);
    }

    //模拟数据
    private ArrayList<String> initData() {

        ArrayList<String> data = new ArrayList<>();
        String str = "item-";
        for (int i = 0; i< 30; i++) {
            data.add(str + i);
        }

        return data;
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.add_item:
                adapter.addItem(1);
                break;
            case R.id.delete_item:
                adapter.deleteItem(1);
                break;
        }
    }
}

activity_recyclerview.xml

<?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="match_parent"
    android:orientation="vertical"
    tools:context="com.example.testnewas.activity.RActivity">

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

        <TextView
            android:id="@+id/add_item"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:background="#fff000"
            android:text="添加item"/>

        <TextView
            android:id="@+id/delete_item"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:background="#cccccc"
            android:text="删除item"/>


    </LinearLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/my_recycle_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="vertical">

    </android.support.v7.widget.RecyclerView>

</LinearLayout>

RecyclerViewAdapter.java

package com.example.testnewas.adapters;

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.example.testnewas.R;

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

/**
 * Created by ylh on 2017/11/7 0007.
 */

public class Radapter extends RecyclerView.Adapter<Radapter.ViewHodler> {

    private ArrayList<String> mData;

    private OnItemClickListener onItemClickListener;

    private ArrayList<Integer> heights;

    /**
     * 设置回调监听
     * @param onItemClickListener
     */
    public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
        this.onItemClickListener = onItemClickListener;
    }


    public Radapter(ArrayList<String> mData) {
        this.mData = mData;
        getRandomHeight(this.mData);
    }

    public void updateData(ArrayList<String> mData) {
        this.mData = mData;
        notifyDataSetChanged();
    }

    @Override
    public ViewHodler onCreateViewHolder(ViewGroup parent, int viewType) {

        //实例化展示的view
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.view_rv_item, parent, false);
        //实例化viewhodler
        ViewHodler viewHodler = new ViewHodler(view);
        return viewHodler;
    }

    @Override
    public void onBindViewHolder(ViewHodler holder, final int position) {

        /**
         *瀑布流实现
         */
        // 得到item的LayoutParams布局参数
        ViewGroup.LayoutParams params= holder.itemView.getLayoutParams();
        //把随机的高度赋予item布局
        params.height = heights.get(position);
        // 把params设置给item布局
        holder.itemView.setLayoutParams(params);

        //绑定数据
        holder.mTv.setText(mData.get(position));

        if (onItemClickListener != null) {

            holder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    onItemClickListener.onClick(position);
                }
            });

            holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
                @Override
                public boolean onLongClick(View view) {
                    onItemClickListener.onLongClick(position);
                    //表示此事件已经消费，不会触发单击事件
                    return true;
                }
            });
        }
    }

    //得到随机item的高度
    private void getRandomHeight(List<String> datas) {
        heights = new ArrayList<Integer>();
        for (int i = 0; i < datas.size(); i++) {
            heights.add((int) (200+Math.random()*100));
        }
    }

    @Override
    public int getItemCount() {
        return mData == null?0:mData.size();
    }

    public void addItem(int position) {
        if (mData == null) {
            mData = new ArrayList<>();
        }
        mData.add(position, "new Item");
        //注意，这里更新数据集不是用adapter.notifyDataSetChanged()而是
        //notifyItemInserted(position)与notifyItemRemoved(position) 否则没有动画效果。
        notifyItemInserted(position);
        getRandomHeight(mData);
    }

    public void deleteItem(int position) {
        if (mData == null || mData.isEmpty()) {
            return;
        }
        mData.remove(position);
        notifyItemRemoved(position);
        getRandomHeight(mData);
    }

    public interface OnItemClickListener {
        void onClick(int position);
        void onLongClick(int position);
    }

    public static class ViewHodler extends RecyclerView.ViewHolder{

        TextView mTv;

        public ViewHodler(View itemView) {
            super(itemView);
            mTv = (TextView) itemView.findViewById(R.id.item_tv);
        }
    }
}

view_rv_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:orientation="vertical">
    <TextView
        android:id="@+id/item_tv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:background="#fccfcc"
        android:layout_margin="5dp"
        android:text="item"/>

</LinearLayout>

MyDividerItemDecoration.java

package com.example.testnewas.views;

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

/**
 * Created by ylh on 2017/11/7 0007.
 *
 * RecyclerView的间隔样式
 */

public class MyDividerItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };
    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
    /**
     * 用于绘制间隔样式
     */
    private Drawable mDivider;
    /**
     * 列表的方向，水平/竖直
     */
    private int mOrientation;


    public MyDividerItemDecoration(Context context, int orientation) {
        // 获取默认主题的属性
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
        // 绘制间隔
        if (mOrientation == VERTICAL_LIST) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        if (mOrientation == VERTICAL_LIST) {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }

    private void setOrientation(int orientation) {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }

    /**
     * 绘制间隔
     */
    private void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();
        final int childCount = parent.getChildCount();
        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 +
                    Math.round(ViewCompat.getTranslationY(child));
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    /**
     * 绘制间隔
     */
    private void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();
        final int childCount = parent.getChildCount();
        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 +
                    Math.round(ViewCompat.getTranslationX(child));
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

}

DividerGridItemDecoration.java

package com.example.testnewas.views;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.View;

/**
 * @author zhy
 *
 * RecyclerView-GridView的间隔样式
 */

public class DividerGridItemDecoration extends RecyclerView.ItemDecoration {
    private static final int[] ATTRS = new int[] { android.R.attr.listDivider };
    private Drawable mDivider;

    public DividerGridItemDecoration(Context context)
    {
        final TypedArray a = context.obtainStyledAttributes(ATTRS );
        mDivider = a.getDrawable(0);
        a.recycle();
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state)
    {

        drawHorizontal(c, parent);
        drawVertical(c, parent);

    }

    private int getSpanCount(RecyclerView parent)
    {
        // 列数
        int spanCount = -1;
        RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
        if (layoutManager instanceof GridLayoutManager)
        {

            spanCount = ((GridLayoutManager) layoutManager).getSpanCount();
        } else if (layoutManager instanceof StaggeredGridLayoutManager)
        {
            spanCount = ((StaggeredGridLayoutManager) layoutManager)
                    .getSpanCount();
        }
        return spanCount;
    }

    public void drawHorizontal(Canvas c, RecyclerView parent)
    {
        int childCount = parent.getChildCount();
        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.getLeft() - params.leftMargin;
            final int right = child.getRight() + params.rightMargin
                    + mDivider.getIntrinsicWidth();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    public void drawVertical(Canvas c, RecyclerView parent)
    {
        final int childCount = parent.getChildCount();
        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.getTop() - params.topMargin;
            final int bottom = child.getBottom() + params.bottomMargin;
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicWidth();

            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    private boolean isLastColum(RecyclerView parent, int pos, int spanCount,
                                int childCount)
    {
        RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
        if (layoutManager instanceof GridLayoutManager)
        {
            if ((pos + 1) % spanCount == 0) // 如果是最后一列，则不需要绘制右边
            {
                return true;
            }
        } else if (layoutManager instanceof StaggeredGridLayoutManager)
        {
            int orientation = ((StaggeredGridLayoutManager) layoutManager)
                    .getOrientation();
            if (orientation == StaggeredGridLayoutManager.VERTICAL )
            {
                if ((pos + 1) % spanCount == 0) // 如果是最后一列，则不需要绘制右边
                {
                    return true;
                }
            } else
            {
                childCount = childCount - childCount % spanCount;
                if (pos >= childCount) // 如果是最后一列，则不需要绘制右边
                    return true;
            }
        }
        return false;
    }

    private boolean isLastRaw(RecyclerView parent, int pos, int spanCount,
                              int childCount)
    {
        RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
        if (layoutManager instanceof GridLayoutManager)
        {
            childCount = childCount - childCount % spanCount;
            if (pos >= childCount) // 如果是最后一行，则不需要绘制底部
                return true;
        } else if (layoutManager instanceof StaggeredGridLayoutManager)
        {
            int orientation = ((StaggeredGridLayoutManager) layoutManager)
                    .getOrientation();
            // StaggeredGridLayoutManager 且纵向滚动
            if (orientation == StaggeredGridLayoutManager.VERTICAL )
            {
                childCount = childCount - childCount % spanCount;
                // 如果是最后一行，则不需要绘制底部
                if (pos >= childCount)
                    return true;
            } else
            // StaggeredGridLayoutManager 且横向滚动
            {
                // 如果是最后一行，则不需要绘制底部
                if ((pos + 1) % spanCount == 0)
                {
                    return true;
                }
            }
        }
        return false;
    }

    @Override
    public void getItemOffsets(Rect outRect, int itemPosition,
                               RecyclerView parent)
    {
        int spanCount = getSpanCount(parent);
        int childCount = parent.getAdapter().getItemCount();
        if (isLastRaw(parent, itemPosition, spanCount, childCount))// 如果是最后一行，则不需要绘制底部
        {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        } else if (isLastColum(parent, itemPosition, spanCount, childCount))// 如果是最后一列，则不需要绘制右边
        {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else
        {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(),
                    mDivider.getIntrinsicHeight());
        }
    }
}

自定义间隔样式

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="android:listDivider">@drawable/divider</item >
    </style>

divider.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <!-- 填充的颜色 -->
    <solid android:color ="#ff0000"/>

    <!--  线条大小 -->
    <size android:height ="1dp" android:width ="1dp"/>
</shape>

自定义的各种动画效果，github上已经有很多类似的项目了，这里我们直接引用下： RecyclerViewItemAnimators，大家自己下载查看。

提供了SlideInOutLeftItemAnimator,SlideInOutRightItemAnimator,

SlideInOutTopItemAnimator,SlideInOutBottomItemAnimator等动画效果。

瀑布流效果.png

RecyclerView 使用全体验

RecyclerView 使用全体验

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