Android开发笔记（一百二十二）循环器视图RecyclerView

import com.example.exmrecycler.R;
import com.example.exmrecycler.interfaces.OnItemClickListener;
import com.example.exmrecycler.interfaces.OnItemLongClickListener;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

public class RecyclerAdapter extends RecyclerView.Adapter<ViewHolder> 
		implements OnItemClickListener, OnItemLongClickListener {
	private final static String TAG = "RecyclerAdapter";
	private Context mContext;
	private LayoutInflater mInflater;
	private int mType;
	private String[] mTitleArray;
	
	public RecyclerAdapter(Context context, int type, String[] titleArray) {
		mContext = context;
		mInflater = LayoutInflater.from(context);
		mType = type;
		mTitleArray = titleArray;
	}

	@Override
	public int getItemCount() {
		return mTitleArray.length;
	}

	@Override
	public ViewHolder onCreateViewHolder(ViewGroup vg, int viewType) {
		View v = null;
		ViewHolder holder = null;
		v = mInflater.inflate(R.layout.list_title, vg, false);
		holder = new TitleHolder(v);
		return holder;
	}

	@Override
	public void onBindViewHolder(ViewHolder vh, final int position) {
		TitleHolder holder = (TitleHolder) vh;
		holder.tv_seq.setText(""+(position+1));
		holder.tv_title.setText(mTitleArray[position]);
		LayoutParams params = holder.ll_item.getLayoutParams();
		if (mType == 1) {  //表示是线性布局
			params.height = 50;
			holder.ll_item.setLayoutParams(params);
		} else if (mType == 2) {  //表示是网格布局
			params.height = 100;
			holder.ll_item.setLayoutParams(params);
		} else {  //表示是瀑布流网格布局
			params.height = (int) Math.round(300 * Math.random());
			if (params.height < 60) {
				params.height = 60;
			}
			//很奇怪，setLayoutParams对瀑布流网格不起作用，只能用setHeight
			holder.tv_title.setHeight(params.height);
		}
		
		//列表项的点击事件需要自己实现
		holder.ll_item.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				if (mOnItemClickListener != null) {
					mOnItemClickListener.onItemClick(v, position);
				}
			}
		});
		holder.ll_item.setOnLongClickListener(new OnLongClickListener() {
			@Override
			public boolean onLongClick(View v) {
				if (mOnItemLongClickListener != null) {
					mOnItemLongClickListener.onItemLongClick(v, position);
				}
				return true;
			}
		});
	}
	
	@Override
	public int getItemViewType(int position) {
		//这里返回每项的类型，开发者可自定义头部类型与一般类型，
		//然后在onCreateViewHolder方法中根据类型加载不同的布局，从而实现带头部的网格布局
		return 0;
	}
	
	@Override
	public long getItemId(int position) {
		return position;
	}

	public class TitleHolder extends RecyclerView.ViewHolder {
		public LinearLayout ll_item;
		public TextView tv_seq;
		public TextView tv_title;

		public TitleHolder(View v) {
			super(v);
			ll_item = (LinearLayout) v.findViewById(R.id.ll_item);
			tv_seq = (TextView) v.findViewById(R.id.tv_seq);
			tv_title = (TextView) v.findViewById(R.id.tv_title);
		}
		
	}

	private OnItemClickListener mOnItemClickListener;

	public void setOnItemClickListener(OnItemClickListener listener) {
		this.mOnItemClickListener = listener;
	}

	private OnItemLongClickListener mOnItemLongClickListener;

	public void setOnItemLongClickListener(OnItemLongClickListener listener) {
		this.mOnItemLongClickListener = listener;
	}

	@Override
	public void onItemClick(View view, int position) {
		String desc = String.format("您点击了第%d项，内容是%s", position+1, mTitleArray[position]);
		Toast.makeText(mContext, desc, Toast.LENGTH_SHORT).show();
	}
	
	@Override
	public void onItemLongClick(View view, int position) {
		String desc = String.format("您长按了第%d项，内容是%s", position+1, mTitleArray[position]);
		Toast.makeText(mContext, desc, Toast.LENGTH_SHORT).show();
	}

}

import com.example.exmrecycler.adapter.RecyclerAdapter;
import com.example.exmrecycler.widget.DividerItemDecoration;

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.widget.LinearLayout;

public class LinearActivity extends Activity {
	
	private RecyclerView rv_linear;
	private LinearLayoutManager mLayoutManager;
	private RecyclerAdapter mAdapter;
	private String[] starArray = {"水星", "金星", "地球", "火星", "木星", "土星"};
	private String[] yearArray = {"鼠年", "牛年", "虎年", "兔年", "龙年", "蛇年",
			"马年", "羊年", "猴年", "鸡年", "狗年", "猪年"};

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_linear);
		
		rv_linear = (RecyclerView) findViewById(R.id.rv_linear);
		
		mLayoutManager = new LinearLayoutManager(this);
		mLayoutManager.setOrientation(LinearLayout.VERTICAL);
		rv_linear.setLayoutManager(mLayoutManager);
		
		mAdapter = new RecyclerAdapter(this, 1, yearArray);
		rv_linear.setAdapter(mAdapter);
		
		rv_linear.setItemAnimator(new DefaultItemAnimator());
		rv_linear.addItemDecoration(new DividerItemDecoration(this, 
				DividerItemDecoration.VERTICAL_LIST));
	}
	
}

import com.example.exmrecycler.adapter.RecyclerAdapter;
import com.example.exmrecycler.widget.DividerGridItemDecoration;

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;

public class GridActivity extends Activity {
	
	private RecyclerView rv_grid;
	private GridLayoutManager mLayoutManager;
	private RecyclerAdapter mAdapter;
	private String[] yearArray = {"鼠年", "牛年", "虎年", "兔年", "龙年", "蛇年",
			"马年", "羊年", "猴年", "鸡年", "狗年", "猪年"};

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_grid);
		
		rv_grid = (RecyclerView) findViewById(R.id.rv_grid);
		
		mLayoutManager = new GridLayoutManager(this, 4);
//		mLayoutManager.setSpanCount(3);
//		//以下占位规则的意思是：第一项占四列，第二列和第三项各占两列
//		//如果网格的列数为四，那么第一项将占满第一行，第二列和第三项平分第二行，第三行开始每行有四项
//		mLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
//            @Override
//            public int getSpanSize(int position) {
//            	if (position == 0) {
//                    return 4;
//            	} else if (position==1 || position==2) {
//                    return 2;
//            	} else {
//                    return 1;
//            	}
//            }
//        });
		rv_grid.setLayoutManager(mLayoutManager);
		
		mAdapter = new RecyclerAdapter(this, 2, yearArray);
		rv_grid.setAdapter(mAdapter);
		
		rv_grid.setItemAnimator(new DefaultItemAnimator());
		rv_grid.addItemDecoration(new DividerGridItemDecoration(this));
	}
	
}

import com.example.exmrecycler.adapter.RecyclerAdapter;
import com.example.exmrecycler.widget.SpacesItemDecoration;

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.widget.LinearLayout;

public class StaggeredActivity extends Activity {
	
	private RecyclerView rv_staggered;
	private StaggeredGridLayoutManager mLayoutManager;
	private RecyclerAdapter mAdapter;
	private String[] yearArray = {"鼠年", "牛年", "虎年", "兔年", "龙年", "蛇年",
			"马年", "羊年", "猴年", "鸡年", "狗年", "猪年"};

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_staggered);
		
		rv_staggered = (RecyclerView) findViewById(R.id.rv_staggered);
		
		mLayoutManager = new StaggeredGridLayoutManager(4, LinearLayout.VERTICAL);
//		mLayoutManager.setSpanCount(3);
//		mLayoutManager.setOrientation(LinearLayout.HORIZONTAL);
//		mLayoutManager.setReverseLayout(true);
		rv_staggered.setLayoutManager(mLayoutManager);
		
		mAdapter = new RecyclerAdapter(this, 3, yearArray);
		rv_staggered.setAdapter(mAdapter);
		
		rv_staggered.setItemAnimator(new DefaultItemAnimator());
		//每项周围的空隙是5，那么项与项之间的间隔就是5+5=10。
		SpacesItemDecoration decoration=new SpacesItemDecoration(5);
		rv_staggered.addItemDecoration(decoration);
	}
	
}