RecyclerView之垂直ListView

RecyclerView

5.0后推出的

一.与RceyclerView相关的重要类
（1）Adapter
（2）ViewHolder
（3）LayoutManager
（4）ItemDecoration
（5）ItemAnimator
二.RecyclerView能干什么？
1.替代ListView
2.替代GridView
3.横向ListView
4.横向GridView
5.瀑布流
6.定制Item增加与删除动画

三.案例ListView（垂直的ListView，间隔线是渐变颜色的，默认是白条，）

声明：间隔线的类可以到http://download.youkuaiyun.com/download/tobestrong_csdn/9348767上去下载
是一个DividerItemDecoration.java类可以直接复制到包中使用

这里使用Android studio为例，
首先添加远程依赖
点击File–>Project Structure–>app–>Dependcies–>点击加号–>Library dependenycy–>找到v7的recyclerView–>OK

1.Activity的XML文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
>
<android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerView_list"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</RelativeLayout>

2.ItemXML文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="#44ff0000"
>
    <TextView
        android:id="@+id/recyclerView_list_tv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        ></TextView>

</RelativeLayout>

3.activity中的代码

package com.ceo.recyclerviewtest;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

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

public class RecyclerViewByListViewActivity extends AppCompatActivity {
    private RecyclerView mRecyclerView;
    private List<String> mDatas;
    private SimleAdapter mAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_recycler_view_by_list_view);

        initDatas();

        initViews();

        mAdapter = new SimleAdapter(this,mDatas);
        mRecyclerView.setAdapter(mAdapter);

        /**
         * 设置RecyclerView的布局管理器
         * LinearLayoutManager(将mRecyclerView设置为ListView格式)
         * 第一个参数：当前上下文对象
         * 第二个参数：ListView的展示方向：垂直LinearLayoutManager.VERTICAL，横向 LinearLayoutManager.HORIZONTAL
         */
        LinearLayoutManager linearLayoutManager =
                new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);
        mRecyclerView.setLayoutManager(linearLayoutManager);

        /**
         * 设置RecyclerView的Item间的分割线
         * DividerItemDecoration.VERTICAL_LIST:垂直
         */
        mRecyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL_LIST));

    }

    private void initViews() {
        mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView_list);
    }

    private void initDatas() {
        mDatas = new ArrayList<String>();
        for (int i = 'A'; i <= 'Z' ; i++) {
            mDatas.add(""+(char)i);
        }
    }
}

4.adapter中的代码

package com.ceo.recyclerviewtest;

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.TextView;

import java.util.List;

/**
 * 作者：${孙淇文} on 2016/7/3 19:49
 * 邮箱：nice_sqw@163.com
 */
public class SimleAdapter extends RecyclerView.Adapter<MyViewHolder>{

    private LayoutInflater mInflater;
    private Context mContext;
    private List<String> mDatas;

    public SimleAdapter(Context context,List<String> datas)
    {
        this.mContext=context;
        this.mDatas=datas;
        mInflater = LayoutInflater.from(context);


    }

    //创建ViewHolder
    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = mInflater.inflate(R.layout.listview_item,parent,false);
        MyViewHolder viewHolder = new MyViewHolder(view);
        return viewHolder;
    }

    //绑定ViewHolder
    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
            holder.tv.setText(mDatas.get(position));
    }

    @Override
    public int getItemCount() {
        return mDatas.size();
    }
}
        //定义ViewHolder类
    class MyViewHolder extends RecyclerView.ViewHolder{
        TextView tv;
        public MyViewHolder(View itemView) {
            super(itemView);
            tv = (TextView) itemView.findViewById(R.id.recyclerView_list_tv);

        }
    }

5.在这里把DividerItemDecoration类中的代码粘贴出来
package com.ceo.recyclerviewtest;

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

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.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;

/**
 * This class is from the v7 samples of the Android SDK. It's not by me!
 * <p/>
 * See the license above for details.
 */
public class DividerItemDecoration 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;



    private Drawable mDivider;//item间隔的图片资源

    private int mOrientation;//方向：水平/垂直

    public DividerItemDecoration(Context context, int orientation)
    {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);//默认的白条线，可以更改
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }

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

    /**
     * 绘制间隔线
     * @param c
     * @param parent
     */
    @Override
    public void onDraw(Canvas c, RecyclerView parent)
    {
//      Log.v("recyclerview - itemdecoration", "onDraw()");
         if (mOrientation == VERTICAL_LIST) {
                drawVertical(c, parent);
            } else {
                drawHorizontal(c, parent);
            }
    }

    public 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);
            RecyclerView v = new RecyclerView(
                    parent.getContext());
            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);
        }
    }

    public 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;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    /**
     * 提供绘制分割线的间隙
     * @param outRect
     * @param itemPosition
     * @param parent
     */
    @Override
    public void getItemOffsets(Rect outRect, int itemPosition,
            RecyclerView parent)
    {
        if (mOrientation == VERTICAL_LIST)
        {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else
        {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}

6.想要分割线为渐变颜色

（1）在drawable文件下

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

    android:shape="rectangle"//设置为矩形
    >
    <size android:height="3dp"></size>//高度
    <gradient   //渐变颜色从线条的开头，中间，结尾
        android:startColor="#ffff0000"
        android:centerColor="#ff00ff00"
        android:endColor="#ff0000ff"
        android:type="linear"//类型为线条
        ></gradient>



</shape>

（2）在values的styles文件中，（注意：API的版本不同，你可能需要再不同的values中去添加，如values-v14，values-v21等，这个案例只是在values中去添加的）

<resources>

    <!-- Base application theme. -->
    <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_line_01</item>//添加刚刚上面创建的绘制线条的文件
    </style>

</resources>