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.csdn.net/lmj623565791/article/details/45059587