Android RecyclerView使用（一）

RecyclerView
一种可以替换掉listview gridview 瀑布流等控件的新视图控件，控制视图回收和复用 ==优化内存可以替换listview
与listview的不同之处是：listview缓存convertview不同的是,Recyclerview缓存的是viewholder.
提供了一种插拔式的体验，高度的解耦，异常的灵活，通过设置它提供的不同LayoutManager，ItemDecoration , ItemAnimator实现想要的效果
1、RecyclerView.Adapter 适配器
2、RecyclerView.ItemDecoration 每个item附加的子视图，可用来绘制Divider,设置padding等
3、RecyclerView.ItemAnimator 负责添加、删除数据时的动画效果
4、RecyclerView.ViewHolder 缓存的对象
5、RecyclerView.LayoutManager 布局器，负责Item视图的布局

具体使用1、activity：

	private Activity activity;
	private List<PicData> mpicDatas;
	private MyAdapter adapter;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_recycleview);
		activity = this;

		// 获取recycleView 设置布局管理器 设置items 分割线 设置 item 动画
		RecyclerView my_recycleview = (RecyclerView) this
				.findViewById(R.id.my_recycleview);
		my_recycleview.setLayoutManager(new LinearLayoutManager(
				getApplicationContext()));
		my_recycleview.setItemAnimator(new DefaultItemAnimator());// 设置默认的动画
		mpicDatas = Tool.getData();
		adapter = new MyAdapter(mpicDatas);
		adapter.setOnMyItemClickListener(new OnMyItemClickListener() {

			@Override
			public void OnItemClick(View view, int position) {
				Toast.makeText(activity, "Click" + mpicDatas.get(position),
						Toast.LENGTH_SHORT).show();
				adapter.removeData(position);
			}

			@Override
			public void OnItemLongClick(View view, int position) {
				Toast.makeText(activity, "LongClick" + mpicDatas.get(position),
						Toast.LENGTH_SHORT).show();
				adapter.addData(position, mpicDatas.get(position));
			}
		});
		my_recycleview.setAdapter(adapter);
		// 自定义动画有问题
//		my_recycleview.setItemAnimator(new MyItemAnimator());
	}

　　2、适配器 要处理点击事件和对应的视图处理：

// 提供 个数 和viewholder 已经绑定数据 onBindViewHolder
	// 触发事件 和动画效果需要自己灵活处理
	public class MyAdapter extends RecyclerView.Adapter<ViewHolder> {
		List<PicData> mpicdatas;
		private OnMyItemClickListener mOnItemClickListener;
		public MyAdapter() {
		}
		public MyAdapter(List<PicData> mpicdatas) {
			this.mpicdatas = mpicdatas;
		}
		public MyAdapter(List<PicData> mpicdatas,
				OnMyItemClickListener mOnItemClickListener) {
			this.mpicdatas = mpicdatas;
			this.mOnItemClickListener = mOnItemClickListener;
		}

		// 移除数据
		public void removeData(int po) {
			if(po>mpicdatas.size()-1){
				return;
			}
			mpicdatas.remove(po);
			notifyItemRemoved(po);
		}

		// 指定位置添加数据
		public void addData(int po, PicData mPicData) {

			if(po>mpicdatas.size()){
				po=mpicdatas.size();
			}
			if(po<0){
				po=0;
			}
			mpicdatas.add(po, mPicData);
			notifyItemInserted(po);
		}

		// 获取对象个数
		@Override
		public int getItemCount() {
			return mpicdatas.size();
		}

		// 具体用于绑定对应数据
		@Override
		public void onBindViewHolder(ViewHolder mViewHolder1, int arg1) {
			final MyViewHolder mViewHolder = (MyViewHolder) mViewHolder1;
			PicData mPicData = mpicdatas.get(arg1);
			// mViewHolder.im.setBackground(background)
			mViewHolder.tv_des.setText(mPicData.getDes());
			mViewHolder.tv_name.setText(mPicData.getName());
			// 设置点击事件
			if (mOnItemClickListener != null) {
				// 判断是否设置过点击事件 如果设置过 不再设置 防止重复创建 增加内存开销
				if (!mViewHolder.itemView.hasOnClickListeners()) {
					mViewHolder.itemView
							.setOnClickListener(new OnClickListener() {
								@Override
								public void onClick(View v) {
									int po = mViewHolder.getPosition();
									mOnItemClickListener.OnItemClick(v, po);
								}
							});

					mViewHolder.itemView
							.setOnLongClickListener(new OnLongClickListener() {
								@Override
								public boolean onLongClick(View v) {
									int po = mViewHolder.getPosition();
									mOnItemClickListener.OnItemLongClick(v, po);
									return true;
								}
							});
				}
			}
		}

		// 创建一个可返回的holder 用于回收和复用
		@Override
		public MyViewHolder onCreateViewHolder(ViewGroup parent, int arg1) {
			MyViewHolder holder = new MyViewHolder(LayoutInflater.from(
					RecycleviewActivity.this).inflate(
					R.layout.activity_recycleview_item, parent, false));
			return holder;
		}

		// viewholder 静态内部类
		class MyViewHolder extends ViewHolder {
			private TextView tv_name;
			private TextView tv_des;
			private ImageView im;

			public MyViewHolder(View view) {
				super(view);
				tv_name = (TextView) view.findViewById(R.id.tv_title);
				tv_des = (TextView) view.findViewById(R.id.tv_des);
				im = (ImageView) view.findViewById(R.id.im_holder);
			}
		}

		// 设置点击事件
		public void setOnMyItemClickListener(
				OnMyItemClickListener mOnItemClickListener) {
			this.mOnItemClickListener = mOnItemClickListener;
		}

	}

　　3、点击事件的接口

import android.view.View;

public interface OnMyItemClickListener {
	public void OnItemClick(View view, int position);

	public void OnItemLongClick(View view, int position);
}

　　4、model

public class PicData {
	private String name;
	private String des;
	private String path;

	public PicData() {
	}

	public PicData(String name, String des, String path) {
		this.des = des;
		this.name = name;
		this.path = path;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getDes() {
		return des;
	}

	public void setDes(String des) {
		this.des = des;
	}

	public String getPath() {
		return path;
	}

	public void setPath(String path) {
		this.path = path;
	}

}

　　5、工具

public class Tool {

	/**
	 * 获取对应的测试数据
	 * @return
	 */
	public static List<PicData> getData(){
		String image[]={
				"http://imgsrc.baidu.com/forum/w%3D580/sign=f786dbba8744ebf86d716437e9f8d736/9fe5546034a85edf11571c9a49540923df547580.jpg",
				"http://upload.wendu.cn/2016/0225/thumb_300_0_1456366681530.jpg",
				"http://upload.wendu.cn/2016/0225/thumb_300_0_1456386396842.jpg",
				"http://upload.wendu.cn/2016/0225/thumb_300_0_1456386399211.jpg",
				"http://upload.wendu.cn/2016/0217/thumb_300_0_1455684747338.jpg",
				"http://upload.wendu.cn/2016/0203/thumb_300_0_1454499202633.png",
				"http://upload.wendu.cn/2016/0122/thumb_300_0_1453463650114.jpg",
				"http://upload.wendu.cn/2016/0123/thumb_213_160_1453513340130.png",
				"http://upload.wendu.cn/2016/0129/thumb_300_0_1454030278472.jpg"
		};

		List<PicData>  mlist=new ArrayList<PicData>();
		for(int i=0;i<image.length;i++){
			mlist.add(new PicData("第几张"+i, "测试第几张图片 测试数据"+i, image[i]));
		}
		return mlist;

	}

}

　　6、布局

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

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

</RelativeLayout>