Android之初探RecyclerView
RecyclerView的出现是为了取代ListView和GirdView，因为其可以实现ListView和GirdView的效果，也可以拓展很多效果，而且RecyclerView也做了很多优化。
其使用方法是先通过设置布局管理器来确定布局，然后在通过适配器来将数据和试图进行绑定。这里我举个类似于瀑布流的小例子。
项目地址：http://download.csdn.net/detail/l_vaule/9518356
package com.example.recycleviewtest;
/*
* 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("tz", "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);
}
}
/**
* 为我们的Item预留空间 因为我们的recyclerView默认item间是不留空间的
* @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);
}
}
}
package com.example.recycleviewtest;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.DefaultItemAnimator;
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;
public class MainActivity extends ActionBarActivity {
private RecyclerView recyclerView;
private List<String> mData;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
initData();
initView();
}
private void initView() {
//1,设置线性布局容器
recyclerView.setLayoutManager(new LinearLayoutManager(this));
//2,设置gridView布局容器
// recyclerView.setLayoutManager(new GridLayoutManager(this,4));
recyclerView.setAdapter(new MyAdapter(mData, this));
//3,添加分割线 gitHub DividerItemDecoration
recyclerView.addItemDecoration(new DividerItemDecoration(this, LinearLayoutManager.VERTICAL));
}
private void initData() {
mData = new ArrayList<>();
for (int i = 0; i < 10; i++) {
mData.add("I'm handsome");
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
recyclerView.removeAllViews();
recyclerView.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL));
recyclerView.setAdapter(new StaggerAdapter(this, mData));
//添加条目或者删除条目的动画 ----- 系统已经提供了默认的动画 我们也可以自己写 gitHub
recyclerView.setItemAnimator(new DefaultItemAnimator());
return true;
}
return super.onOptionsItemSelected(item);
}
}
package com.example.recycleviewtest;
import java.util.List;
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;
/**
* @author ctt:
* @version 创建时间：2016年5月12日
* 类说明
*/
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder>{
private List<String> mData;
private Context context;
public MyAdapter(List<String> mData, Context context) {
super();
this.mData = mData;
this.context = context;
}
@Override
public int getItemCount() {
// TODO Auto-generated method stub
return mData.size();
}
@Override
public void onBindViewHolder(ViewHolder arg0, int arg1) {
arg0.textView.setText(mData.get(arg1));
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup arg0, int arg1) {
View view = LayoutInflater.from(context).inflate(R.layout.layout_item, arg0,false);
return new ViewHolder(view);
}
class ViewHolder extends RecyclerView.ViewHolder{
TextView textView;
public ViewHolder(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.tv);
}
}
}
package com.example.recycleviewtest;
import java.util.ArrayList;
import java.util.List;
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;
/**
* @author ctt:
* @version 创建时间：2016年5月12日
* 类说明
*/
public class StaggerAdapter extends RecyclerView.Adapter<StaggerAdapter.StgViewHolder>{
private List<String> mDatas;
private LayoutInflater inflater;
private List<Integer> mHeights;
public StaggerAdapter(Context context,List<String> mDatas){
this.mDatas = mDatas;
this.inflater = LayoutInflater.from(context);
mHeights = new ArrayList<Integer>();
//随机为每一个item设置高度
for(int i=0;i<mDatas.size();i++){
mHeights.add((int)(100+Math.random()*300));
}
}
@Override
public StaggerAdapter.StgViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.layout_item,parent,false);
return new StgViewHolder(view);
}
@Override
public void onBindViewHolder(StgViewHolder arg0, int arg1) {
//设置每一个item随机高度
ViewGroup.LayoutParams params = arg0.textView.getLayoutParams();
params.height = mHeights.get(arg1);
arg0.textView.setLayoutParams(params);
arg0.textView.setText(mDatas.get(arg1));
}
@Override
public int getItemCount() {
return mDatas.size();
}
/**
* listView :ViewHolder
*
* 条目的布局：base_item
*/
class StgViewHolder extends RecyclerView.ViewHolder{
TextView textView;
public StgViewHolder(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.tv);
}
}
}