public class RecyclerView extends ViewGroup implements ScrollingView, NestedScrollingChild {}
由上面的繼承結(jié)構(gòu)，我們?nèi)菀卓闯觯?RecyclerView實際上也是一個ViewGroup繼承了ScrollingView和NestedScrolling，方便實現(xiàn)橫向與縱向滑動摔寨。
RecyclerView是support-v7包中的新組件迈着，是一個強(qiáng)大的滑動組件竭望，與經(jīng)典的ListView相比，同樣擁有item回收復(fù)用的功能裕菠，但是直接把viewholder的實現(xiàn)封裝起來咬清，用戶只要實現(xiàn)自己的viewholder就可以了，該組件會自動幫你回收復(fù)用每一個item奴潘。
RecyclerView的優(yōu)點：
1.它不關(guān)心item是否顯示的位置與方式---> layoutManager 我們可以僅僅使用layoutManager一句話就可以切換RecyclerView的樣式
2.它不關(guān)心item如何分割--->ItemDecoration 我們可以根據(jù)自己項目的需要自定義自己的分割線
3.它不關(guān)心item增加與刪除動畫的效果--->ItemAnimator我們可以根據(jù)自己的需要定義item的增加與刪除動畫
4.僅僅關(guān)心如何服用view--->ViewHolder google強(qiáng)制我們使用viewHolder旧烧，我們需要自己定義自己的ViewHolder哦。
RecyclerView的缺點：
1.內(nèi)部沒有實現(xiàn)對單個Item點擊事件的監(jiān)聽萤彩，需要自己定義item的單擊和長按事件粪滤。
2.對item增加后的position測量不準(zhǔn)確，需要在adapter中使用holer.getLayoutPosition()方法獲取雀扶。
由上我們不難看出，RecyclerView的優(yōu)點遠(yuǎn)遠(yuǎn)大于它的缺點啊肆汹，再說它的缺點也不算缺點啊愚墓，都有很好的解決辦法，那么我們還有什么理由不是喲不過它呢昂勉？
SO浪册，我們開始吧。首先岗照，我們需要引入官方提供的向下兼容的V7包村象，具體引入方法，這里不再贅述攒至。
下一步在xml文件中引入 RecyclerView厚者。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerview"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>
MainActivity
package com.flyou.henucenter.recycterview;
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.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;
import com.flyou.henucenter.recycterview.adpater.RecyclerViewAdapter;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private RecyclerViewAdapter recyclerViewAdapter;
private List<String> datas;
private RecyclerView recyclerview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initdate();
initView();
}
private void initdate() {
datas = new ArrayList<>();
for (int i = 'A'; i < 'z'; i++) {
datas.add((char) i + "");
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch (id) {
//Gridview
case R.id.action_Gridview:
GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 4, GridLayoutManager.VERTICAL, false);
recyclerview.setLayoutManager(gridLayoutManager);
break;
case R.id.action_Listview:
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
recyclerview.setLayoutManager(linearLayoutManager);
break;
case R.id.action_hor_GridView:
GridLayoutManager hor_gridLayoutManager = new GridLayoutManager(this, 4, GridLayoutManager.HORIZONTAL, false);
recyclerview.setLayoutManager(hor_gridLayoutManager);
break;
case R.id.action_pubu:
break;
case R.id.action_add:
recyclerViewAdapter.add(1);
break;
case R.id.action_delete:
recyclerViewAdapter.delete(1);
break;
}
return super.onOptionsItemSelected(item);
}
private void initView() {
recyclerview = (RecyclerView) findViewById(R.id.recyclerview);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
recyclerview.setLayoutManager(layoutManager);
// recyclerview.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST));
recyclerview.setItemAnimator(new DefaultItemAnimator());
recyclerViewAdapter = new RecyclerViewAdapter(datas, this);
recyclerview.setAdapter(recyclerViewAdapter);
recyclerViewAdapter.setOnItemClickListener(new RecyclerViewAdapter.OnItemClickListener() {
@Override
public void onItemClick(View view, int Position) {
Toast.makeText(MainActivity.this, "itemClick" + Position, Toast.LENGTH_SHORT).show();
}
@Override
public void onItemLongClick(View view, int Position) {
Toast.makeText(MainActivity.this, "ItemLongClick" + Position, Toast.LENGTH_SHORT).show();
}
});
}
}
Adapter文件
package com.flyou.henucenter.recycterview.adpater;
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 com.flyou.henucenter.recycterview.R;
import java.util.List;
/**
* 項目名稱:My Application
*
* 包名:com.flyou.henucenter.myapplication.adpater
* 作者: flyou
* 創(chuàng)建時間:15/8/19 11:42
* 描述:
*/
public class RecyclerViewAdapter extends RecyclerView.Adapter<MyViewHolder> {
private List<String> mDatas;
private Context mContex;
private LayoutInflater mInFlater;
//設(shè)置item的回調(diào)
public interface OnItemClickListener {
void onItemClick(View view, int Position);
void onItemLongClick(View view, int Position);
}
private OnItemClickListener onItemClickListener;
public void setOnItemClickListener(OnItemClickListener listener) {
this.onItemClickListener = listener;
}
public RecyclerViewAdapter(List<String> datas, Context Contex) {
this.mContex = Contex;
this.mDatas = datas;
mInFlater = LayoutInflater.from(mContex);
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = mInFlater.inflate(R.layout.item_view, parent, false);
MyViewHolder viewHolder = new MyViewHolder(view);
return viewHolder;
}
public void add(int pos) {
mDatas.add(pos, "I am new item ");
notifyItemInserted(pos);
}
public void delete(int pos) {
mDatas.remove(pos);
notifyItemRemoved(pos);
}
@Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
holder.textView.setText(mDatas.get(position));
if (onItemClickListener != null) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int layoutPosition = holder.getLayoutPosition();
onItemClickListener.onItemClick(holder.itemView,layoutPosition);
}
});
holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
int layoutPosition = holder.getLayoutPosition();//增加或刪除item使用這個方法獲得其position
onItemClickListener.onItemLongClick(holder.itemView,layoutPosition);
return false;
}
});
}
}
@Override
public int getItemCount() {
return mDatas.size();
}
}
class MyViewHolder extends RecyclerView.ViewHolder {
TextView textView;
public MyViewHolder(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.textInfo);
}
}
單個Item
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:background="@drawable/item_selector"
android:layout_margin="3dp"
android:layout_width="match_parent"
android:layout_height="70dp"
>
<TextView
android:id="@+id/textInfo"
android:gravity="center"
android:layout_width="72dp"
android:layout_height="match_parent" />
</RelativeLayout>
menu文件
<menu 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"
tools:context=".MainActivity">
<item
android:id="@+id/action_Listview"
android:orderInCategory="100"
android:title="listview"
app:showAsAction="never" />
<item
android:id="@+id/action_Gridview"
android:orderInCategory="100"
android:title="gridView"
app:showAsAction="never" />
<item
android:id="@+id/action_hor_GridView"
android:orderInCategory="100"
android:title="hor_GridView"
app:showAsAction="never" />
<item
android:id="@+id/action_pubu"
android:orderInCategory="100"
android:title="pubuliu"
app:showAsAction="never" />
<item
android:id="@+id/action_add"
android:orderInCategory="100"
android:icon="@drawable/ic_menu_add"
android:title="add"
app:showAsAction="always" />
<item
android:id="@+id/action_delete"
android:orderInCategory="100"
android:icon="@drawable/ic_menu_delete"
android:title="delete"
app:showAsAction="always" />
</menu>
//設(shè)置回調(diào)接口，方便在調(diào)用出進(jìn)行處理迫吐。
public interface OnItemClickListener {
void onItemClick(View view, int Position);
void onItemLongClick(View view, int Position);
}
private OnItemClickListener onItemClickListener;
public void setOnItemClickListener(OnItemClickListener listener) {
this.onItemClickListener = listener;
沒有錄制gif大家湊合著看效果库菲。
當(dāng)然，item的增加和刪除是有動畫的志膀，大家也可以在github上所有相關(guān)的動畫庫進(jìn)行使用
https://github.com/gabrielemariotti/RecyclerViewItemAnimators
上面給出其中一個比較出色的RecylerView庫熙宇。
大家也可以根據(jù)自己的需要自行定制，ok就先介紹到這里溉浙。
