RecyclerView 数据刷新的几种方式

Posted 2020-09-21 白乾涛

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小结

刷新全部可见的item，notifyDataSetChanged()
刷新指定item，notifyItemChanged(int)
从指定位置开始刷新指定个item，notifyItemRangeChanged(int,int)
插入、移动一个并自动刷新，notifyItemInserted(int)、notifyItemMoved(int)、notifyItemRemoved(int)
局部刷新，notifyItemChanged(int, Object)

Activity

public class Notify_Activity extends Activity implements MyOnItemClickLitener {
	private RecyclerView mRecyclerView;
	private Notify_Adapter mAdapter;
	private ArrayList<PicUrls.BasicPicBean> beans;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		((SwipeRefreshLayout) findViewById(R.id.swipeLayout)).setEnabled(false);
		mRecyclerView = (RecyclerView) findViewById(R.id.rv);
		initList();
		initView();
	}
	
	protected void initView() {
		mAdapter = new Notify_Adapter(this, beans);
		mAdapter.setOnItemClickLitener(this);
		mRecyclerView.setAdapter(mAdapter);//设置adapter
		mRecyclerView.setLayoutManager(new GridLayoutManager(this, 3));//设置布局管理器
		mRecyclerView.setItemAnimator(new DefaultItemAnimator());//设置Item增加、移除动画
		mRecyclerView.addItemDecoration(new GridItemDecoration.Builder().spanCount(3)
				.spaceSize(1).mDivider(new ColorDrawable(0x88ff0000)).build());
	}
	private void initList() {
		beans = PicUrls.getPicList(PicUrls.BIG_BEANS_2);
		beans.get(0).name = "刷新当前，notifyItemChanged(int)";
		beans.get(1).name = "全部刷新，notifyDataSetChanged()";
		beans.get(2).name = "从此位置开始刷新2个，notifyItemRangeChanged";
		beans.get(3).name = "插入一个并自动刷新，notifyItemInserted";
		beans.get(4).name = "只更改数据源，这样当然不会刷新UI";
		beans.get(5).name = "插入一个并刷新当前，notifyItemChanged";
		beans.get(6).name = "局部刷新，tv";
		beans.get(7).name = "局部刷新，et";
		beans.get(8).name = "局部刷新，iv";
	}
	@Override
	public void onItemClick(View view, int position) {
		Toast.makeText(this, position + " 被点击了", Toast.LENGTH_SHORT).show();
		reInit(position);
	}
	
	@Override
	public void onItemLongClick(View view, int position) {
		Toast.makeText(this, position + "被长按了", Toast.LENGTH_SHORT).show();
	}
	private void reInit(int position) {
		switch (position) {
			default:
				mAdapter.notifyItemChanged(position);//刷新指定一个。一定会闪
				break;
			case 1:
				mAdapter.notifyDataSetChanged();//全部刷新。基本不会闪，刚开始个别可能会闪
				break;
			case 2:
				mAdapter.notifyItemRangeChanged(position, 2);//从指定位置开始刷新指定个。一定会闪
				break;
			case 3:
				beans.add(position, new PicUrls.BasicPicBean("http://img.mmjpg.com/2015/74/1.jpg", "新插入的图片1", 1));
				mAdapter.notifyItemInserted(position);//插入一个并刷新，正常
				break;
			case 4://只更改数据源，这样当然不会刷新UI
				beans.add(position, new PicUrls.BasicPicBean("http://img.mmjpg.com/2015/74/2.jpg", "新插入的图片2", 2));
				break;
			case 5://
				beans.add(position, new PicUrls.BasicPicBean("http://img.mmjpg.com/2015/74/3.jpg", "新插入的图片3", 3));
				mAdapter.notifyItemChanged(position);//这样只会导致当前item刷新，而不会刷新其他item，当然是不行的
				break;
			case 6:
				beans.set(position, beans.get(new Random().nextInt(beans.size())));
				mAdapter.notifyItemChanged(position, Notify_Adapter.NOTIFY_TV);//局部刷新
				break;
			case 7:
				beans.set(position, beans.get(new Random().nextInt(beans.size())));
				mAdapter.notifyItemChanged(position, Notify_Adapter.NOTIFY_ET);//局部刷新
				break;
			case 8:
				beans.set(position, beans.get(new Random().nextInt(beans.size())));
				mAdapter.notifyItemChanged(position, Notify_Adapter.NOTIFY_IV);//局部刷新
				break;
		}
	}
}

Adapter

public class Notify_Adapter extends RecyclerView.Adapter<Notify_Adapter.MyViewHolder> {
	private Context context;
	private List<PicUrls.BasicPicBean> mDatas;
	private MyOnItemClickLitener mOnItemClickLitener;
	public static final int NOTIFY_TV = 10086;
	public static final int NOTIFY_ET = 10087;
	public static final int NOTIFY_IV = 10088;
	public Notify_Adapter(Context context, List<PicUrls.BasicPicBean> mDatas) {
		this.context = context;
		this.mDatas = mDatas;
	}
	@Override
	public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
		return new MyViewHolder(LayoutInflater.from(context).inflate(R.layout.item_notify, parent, false));
	}
	@Override
	public void onBindViewHolder(MyViewHolder holder, int position) {
		//不使用
	}
	@Override
	public void onBindViewHolder(final MyViewHolder holder, int position, List payloads) {
		//payloads是从notifyItemChanged(int, Object)中，或从notifyItemRangeChanged(int, int, Object)中传进来的Object集合
		//如果payloads不为空并且viewHolder已经绑定了旧数据了，那么adapter会使用payloads参数进行布局刷新
		//如果payloads为空，adapter就会重新绑定数据，也就是刷新整个item
		PicUrls.BasicPicBean bean = mDatas.get(holder.getAdapterPosition());
		long time = System.currentTimeMillis() + bean.url.hashCode();
		String data = new SimpleDateFormat("HH:mm:ss", Locale.getDefault()).format(new Date(time));
		if (payloads.isEmpty()) {//为空，即不是调用notifyItemChanged(position,payloads)后执行的，也即在初始化时执行的
			holder.tv.setText(data);
			holder.et.setText(bean.name);
			Glide.with(context).load(bean.url)
					.dontAnimate()
					//.diskCacheStrategy(DiskCacheStrategy.NONE).skipMemoryCache(true)
					.into(holder.iv);
		} else if (payloads.size() > 0 && payloads.get(0) instanceof Integer) {
			//不为空，即调用notifyItemChanged(position,payloads)后执行的，可以在这里获取payloads中的数据进行局部刷新
			int type = (int) payloads.get(0);// 刷新哪个部分 标志位
			switch (type) {
				case NOTIFY_TV:
					holder.tv.setText(data);//只刷新tv
					break;
				case NOTIFY_ET:
					holder.et.setText(bean.name);//只刷新et
					break;
				case NOTIFY_IV:
					Glide.with(context).load(bean.url).dontAnimate().into(holder.iv);//只刷新iv
					break;
			}
		}
		// 如果设置了回调，则设置点击事件
		holder.itemView.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				if (mOnItemClickLitener != null) mOnItemClickLitener.onItemClick(holder.itemView, holder.getAdapterPosition());
			}
		});
		holder.itemView.setOnLongClickListener(new OnLongClickListener() {
			@Override
			public boolean onLongClick(View v) {
				if (mOnItemClickLitener != null) mOnItemClickLitener.onItemLongClick(holder.itemView, holder.getAdapterPosition());
				return false;
			}
		});
	}
	@Override
	public int getItemCount() {
		return mDatas.size();
	}
	/**
	 * 添加并更新数据，同时具有动画效果
	 */
	public void addDataAt(int position, PicUrls.BasicPicBean data) {
		mDatas.add(position, data);
		notifyItemInserted(position);//更新数据集，注意如果用adapter.notifyDataSetChanged()将没有动画效果
	}
	/**
	 * 移除并更新数据，同时具有动画效果
	 */
	public void removeDataAt(int position) {
		mDatas.remove(position);
		notifyItemRemoved(position);
	}
	public void setOnItemClickLitener(MyOnItemClickLitener mOnItemClickLitener) {
		this.mOnItemClickLitener = mOnItemClickLitener;
	}
	class MyViewHolder extends RecyclerView.ViewHolder {
		TextView tv;
		ImageView iv;
		EditText et;
		public MyViewHolder(View view) {
			super(view);
			tv = (TextView) view.findViewById(R.id.tv_name);
			iv = (ImageView) view.findViewById(R.id.iv_head);
			et = (EditText) view.findViewById(R.id.et_input);
		}
	}
}

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:gravity="center_horizontal"
              android:orientation="vertical">
    <TextView
        android:id="@+id/tv_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="0.00"
        android:textColor="#00f"
        android:textSize="13sp"/>
    <ImageView
        android:id="@+id/iv_head"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:scaleType="centerCrop"
        android:src="@mipmap/ic_launcher"/>
    <EditText
        android:id="@+id/et_input"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:hint="包青天"
        android:inputType="numberDecimal"
        android:labelFor="@id/et_input"
        android:maxLines="1"
        android:minWidth="50dp"
        android:textColor="#f00"
        android:textSize="10sp"/>
</LinearLayout>

获取图片集合

public class PicUrls {
	private static final String HOST0 = "http://img1.mm131.com/pic/";//网站【http://www.mm131.com/】
	private static final String HOST1 = "http://img.mmjpg.com/";//网站【http://www.mmjpg.com/】
	private static final String HOST2 = "http://pic.meituba.com/uploads/allimg/";//网站【http://www.meituba.com/】
	public static final UrlBean BIG_BEANS_0 = new UrlBean.Builder()//http://pic.meituba.com/uploads/allimg/2015/10/23/220.jpg
			.host(HOST2).urlHeader("2015/10/23/").picIndexFrom(220).picCount(100).picDes("100张动漫卡通壁纸").build();
	public static final UrlBean BIG_BEANS_1 = new UrlBean.Builder()//http://pic.meituba.com/uploads/allimg/2017/03/27/121_5600.jpg
			.host(HOST2).urlHeader("2017/03/27/121_").picIndexFrom(5600).picCount(100).picDes("100张搞笑内涵图片").build();
	public static final UrlBean BIG_BEANS_2 = new UrlBean.Builder()//http://pic.meituba.com/uploads/allimg/2015/10/23/360.jpg
			.host(HOST2).urlHeader("2015/10/23/").picIndexFrom(360).picCount(750).picDes("750张性感美女图").build();
	public static final UrlBean BIG_BEANS_3 = new UrlBean.Builder()//http://pic.meituba.com/uploads/allimg/2016/03/25/43_20335.jpg
			.host(HOST2).urlHeader("2016/03/25/43_").picIndexFrom(20335).picCount(1400).picDes("1400张动漫卡通壁纸").build();
	private static final UrlBean[] simpleBeans = {
			//http://img1.mm131.com/pic/996/1.jpg
			new UrlBean.Builder().host(HOST0).urlHeader("996/").picCount(10).picDes("北影校花余雨高清写真图片").build(),
			new UrlBean.Builder().host(HOST0).urlHeader("2958/").picCount(10).picDes("童颜嫩妹桃子黑丝大尺度诱惑").build(),
			new UrlBean.Builder().host(HOST0).urlHeader("2939/").picCount(10).picDes("清纯少女刘奕宁酥胸覆白色内衣").build(),
			new UrlBean.Builder().host(HOST0).urlHeader("2343/").picCount(10).picDes("萌妹销魂写真身材惹火让人欲罢不能").build(),
			new UrlBean.Builder().host(HOST0).urlHeader("2935/").picCount(10).picDes("性感女神杨晨晨透视睡衣大胆秀乳").build(),
			//http://img.mmjpg.com/2015/444/1.jpg
			new UrlBean.Builder().host(HOST1).urlHeader("2015/444/").picCount(10).picDes("模范学院美少女柳侑绮制服大片").build(),
			new UrlBean.Builder().host(HOST1).urlHeader("2015/74/").picCount(10).picDes("极品女神可儿私拍秀完美身材").build(),
			new UrlBean.Builder().host(HOST1).urlHeader("2017/990/").picCount(10).picDes("香艳妹子雪白的美胸绝对让你大饱眼福").build(),
			new UrlBean.Builder().host(HOST1).urlHeader("2017/962/").picCount(10).picDes("真诱人啊!女神雪白的美胸看着很有感觉").build(),
			new UrlBean.Builder().host(HOST1).urlHeader("2017/936/").picCount(10).picDes("身材娇美纯天然美女小叶子美胸艺术照").build(),
			//http://pic.meituba.com/uploads/allimg/2015/10/23/247.jpg
			new UrlBean.Builder().host(HOST2).urlHeader("2015/10/23/").picIndexFrom(247).picCount(10).picDes("呆萌可爱的哆啦A梦动漫").build(),
			new UrlBean.Builder().host(HOST2).urlHeader("2016/03/25/43_").picIndexFrom(20574).picCount(10).picDes("海贼王红发香克斯").build(),
			new UrlBean.Builder().host(HOST2).urlHeader("2016/03/25/44_").picIndexFrom(11275).picCount(10).picDes("英雄联盟游戏图片").build(),
			new UrlBean.Builder().host(HOST2).urlHeader("2016/07/30/43_").picIndexFrom(485).picCount(10).picDes("精选超萌小猫咪").build(),
			new UrlBean.Builder().host(HOST2).urlHeader("2016/09/08/43_").picIndexFrom(476).picCount(10).picDes("可爱快乐的女孩动漫").build(),
	};
	//******************************************************************************************
	/**
	 * 10*15张各种各样的带有描述的图片
	 */
	public static ArrayList<BasicPicBean> getPicList() {
		List<UrlBean> urlList = Arrays.asList(simpleBeans);
		ArrayList<BasicPicBean> picList = new ArrayList<>();
		for (UrlBean bean : urlList) {
			picList.addAll(getPicList(bean));
		}
		return picList;
	}
	/**
	 * 每一个UrlBean都有超多图片，多的有几千张
	 */
	public static ArrayList<BasicPicBean> getPicList(UrlBean bean) {
		ArrayList<BasicPicBean> picList = new ArrayList<>();
		for (int i = 0; i < bean.picCount; i++) {
			String picIndex = "" + (bean.picIndexFrom + i);
			for (int j = picIndex.length(); j < bean.minLength; j++) {
				if (picIndex.length() < bean.minLength) {
					picIndex = "0" + picIndex;
				} else break;
			}
			String picUrl = bean.host + bean.urlHeader + picIndex + bean.urlEnder;//例如.../1.jpg
			String picDes = bean.picDes + "-" + i;
			picList.add(new BasicPicBean(picUrl, picDes, i));
		}
		return picList;
	}
	//******************************************************************************************
	static class UrlBean {
		public String picDes;//图片描述
		public String host;//存放图片的主机地址
		public String urlHeader;
		public String urlEnder;//默认为= ".jpg"
		public int picCount;//此系列图片的数量。所有图片都是以数字命名的，比如1.jpg、2.jpg
		public int picIndexFrom;//此系列图片开始的序号位置，默认为1
		public int minLength;//如，当为1.jpg时实际为01.jpg或001.jpg
		private UrlBean(Builder builder) {
			picDes = builder.picDes;
			host = builder.host;
			urlHeader = builder.urlHeader;
			urlEnder = builder.urlEnder;
			picCount = builder.picCount;
			picIndexFrom = builder.picIndexFrom;
			minLength = builder.minLength;
		}
		static final class Builder {
			private String picDes = "包青天作品";
			private String host = "";
			private String urlHeader = "";
			private String urlEnder = ".jpg";//默认为".jpg"
			private int picCount = 1;
			private int picIndexFrom = 1;
			private int minLength = 0;
			public Builder() {
			}
			public Builder urlHeader(String val) {
				urlHeader = val;
				return this;
			}
			public Builder urlEnder(String val) {
				urlEnder = val;
				return this;
			}
			public Builder picCount(int val) {
				picCount = val;
				return this;
			}
			public Builder picIndexFrom(int val) {
				picIndexFrom = val;
				return this;
			}
			public Builder minLength(int val) {
				minLength = val;
				return this;
			}
			public Builder host(String val) {
				host = val;
				return this;
			}
			public Builder picDes(String val) {
				picDes = val;
				return this;
			}
			public UrlBean build() {
				return new UrlBean(this);
			}
		}
	}
	//******************************************************************************************
	public static class BasicPicBean {
		public String url;
		public String name;
		public int index;
		public BasicPicBean(String url, String name, int index) {
			this.url = url;
			this.name = name;
			this.index = index;
		}
	}
}

2017-6-7

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