商城之RecyclerView 详细介绍

0.RecylerView用法

(1).Datas:    要显示的数据

(2).Adapter：适配器，绑定数据集 

(3).ViewHolder：根据当前的数据保存视图 

(4).LayoutManager：布局管理器。决定item如何摆放 

(5).ItemDecoration：勉强理解为item装饰器，可以美化item 

(6). ItemAnimator：动画（当item被增加，删除，重新摆放时动画才有效）。

(7). Listener： 事件。RecyclerView 本身不提供OnItemClickListener 等事件

1.在gradle中配置

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:23.0.1'
    compile 'com.android.support:recyclerview-v7:23.0.1'

}

2.布局 activity_main.xml

<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"

    tools:context=".MainActivity">


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


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



</RelativeLayout>

3.item布局

<?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="wrap_content"
    android:background="@drawable/selector_item_bg"
    android:gravity="center"
    android:padding="20dp"
    >

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_gravity="center"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:textColor="#fff"
        android:textSize="20dp"
        android:padding="20dp"
        android:text="1" />

</LinearLayout>

4.MainActivity.java

package cniao5.com.rvdemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
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.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;

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

public class MainActivity extends AppCompatActivity {




    private RecyclerView mRecyclerView;


    private List<String> datas = new ArrayList<>();

    private  MyAdatper mAdatper;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        initDatas();

        mRecyclerView = (RecyclerView) this.findViewById(R.id.recyclerView);


        mAdatper = new MyAdatper(datas);
        mRecyclerView.setAdapter(mAdatper);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));  //必须要设置
		// mRecyclerView.setLayoutManager(new GridLayoutManager(this,4));  变为GridView
		// mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(4,1)); 变为瀑布流

		
		//画分割线，需要写一个类
        mRecyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL_LIST));
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());


		//点击事件，需要在Adapter中设置
        mAdatper.setOnItemClickListener(new MyAdatper.OnItemClickListener() {
            @Override
            public void onClick(View v, int position, String city) {

                Toast.makeText(MainActivity.this,"city:"+city+",position:"+position,Toast.LENGTH_LONG).show();
            }
        });






    }


    private  void initDatas(){

        datas.add("New York");
        datas.add("Boston");
        datas.add("Washington");
        datas.add("San Francisco");
        datas.add("California");
        datas.add("Chicago");
        datas.add("Houston");
        datas.add("Phoenix");
        datas.add("Philadelphia");
        datas.add("Pennsylvania");
        datas.add("San Antonio");
        datas.add("Austin");
        datas.add("Milwaukee");
        datas.add("Las Vegas");
        datas.add("Oklahoma");
        datas.add("Portland");
        datas.add("Mexico");

    }





    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
        switch (item.getItemId())
        {
            case R.id.id_action_add:
                mAdatper.addData(0,"new Citiy");
                break;
            case R.id.id_action_delete:
                mAdatper.removeData(1);
                break;
            case R.id.id_action_gridview:
                mRecyclerView.setLayoutManager(new GridLayoutManager(this, 4));
                break;
            case R.id.id_action_listview:
                mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
                break;
            case R.id.id_action_horizontalGridView:
                mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(4,
                        StaggeredGridLayoutManager.HORIZONTAL));
                break;

        }
        return true;
    }










}

5.MyAdapter.java

package cniao5.com.rvdemo;

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;

/**
 * Created by Ivan on 15/9/30. //适配器
 */
 //需要继承RecyclerView.Adapter并传入ViewHolder
public class MyAdatper  extends RecyclerView.Adapter<MyAdatper.ViewHolder> {

   //RecyclerView事件监听放在Adapter

    private List<String> mDatas;


    private LayoutInflater inflater;


    public MyAdatper(List<String> datas){

        mDatas = datas;
    }

	//相当于getView方法
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

	    //需要把每一个item的View传入ViewHolder
        inflater = LayoutInflater.from(parent.getContext());
        View view = inflater.inflate(R.layout.item,parent,false);
        return new ViewHolder(view);
    }



	//绑定数据和View
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {


        holder.textView.setText(mDatas.get(position));

    }

    @Override
    public int getItemCount() {
        return mDatas.size();
    }



	//添加一个item
    public  void addData(int position,String city){

        mDatas.add(position,city);

//        notifyItemChanged(position);

        notifyItemInserted(position);

    }


    //移除一个item
    public void removeData(int position){

        mDatas.remove(position);

        notifyItemRemoved(position);
    }


    //需要继承RecyclerView.ViewHolder
    class  ViewHolder extends  RecyclerView.ViewHolder{


        private TextView textView;

        public ViewHolder(View itemView) {
            super(itemView);

            textView = (TextView) itemView.findViewById(R.id.text);

			//绑定监听事件
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    if(listener !=null){
                        listener.onClick(v,getLayoutPosition(),mDatas.get(getLayoutPosition()));
                    }

                }
            });


        }
    }


	
	private  OnItemClickListener listener;

    public void setOnItemClickListener(OnItemClickListener listener){

        this.listener = listener;
    }
	
    //创建一个接口，事件监听
    interface  OnItemClickListener{


        void onClick(View v,int position,String city);


    }




}

6.DividerItemDecoration   分割线

package cniao5.com.rvdemo;

/*
 * 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;

	private int mOrientation;

	public DividerItemDecoration(Context context, int orientation)
	{
		final TypedArray a = context.obtainStyledAttributes(ATTRS);
		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;
	}

	@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);
			android.support.v7.widget.RecyclerView v = new android.support.v7.widget.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);
		}
	}

	@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);
		}
	}
}

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1.http://blog.youkuaiyun.com/lmj623565791/article/details/45059587