RecyclerView的基本功能介绍: 1. 通过setLayoutManager方法可以设置布局,几个子类布局如下:
-> LinearLayoutManager(ListView形式的布局)
-> GridLayoutManager(GridView形式的布局)
-> StaggeredGridLayoutManager(瀑布流形式的布局,其实本质还是GridView,只是每个Item的高度不一样)
2. 通过addItemDecoration设置Item之间的分割线
3. 通过setItemAnimator设置添加,删除Item时的动画
本文由于需要展示ListView,Vertical GridView,Horizontal GridView和Staggered(瀑布流),所以就不设置Item之间的分割线,直接在XML中设置Item的间距替代。
主界面的布局(activity_main):
Item的布局文件(item_recyclerview):
主界面Activity:
package com.example.testrecyclerview;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.os.Bundle;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.support.v7.widget.StaggeredGridLayoutManager;import android.view.View;import android.widget.Button;import android.widget.Toast;import com.example.testrecyclerview.SimpleAdapter.OnItemClickListener;public class MainActivity extends Activity implements android.view.View.OnClickListener { private RecyclerView mRecyclerView; private ListmDatas; private SimpleAdapter mAdapter; private StaggeredAdapter mStaggeredAdapter; private Button mAddBtn; private Button mDeleteBtn; private Button mMenuBtn; private AlertDialog.Builder mBuilder; private DialogInterface.OnClickListener mListener; private int mType = 0; private final int SIMPLE = 0; private final int STAGGERED = 1; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initData(); initView(); addListener(); // 设置布局 mRecyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)); // 设置动画 mRecyclerView.setItemAnimator(new DefaultItemAnimator()); } protected void initData() { mDatas = new ArrayList (); for (int i = 'A'; i < 'z'; i++) { mDatas.add("" + (char) i); } } private void initView() { mAddBtn = (Button) findViewById(R.id.id_add); mDeleteBtn = (Button) findViewById(R.id.id_delete); mMenuBtn = (Button) findViewById(R.id.id_menu); mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerview); mAdapter = new SimpleAdapter(this, mDatas); mStaggeredAdapter = new StaggeredAdapter(this, mDatas); mRecyclerView.setAdapter(mAdapter); mListener = new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { switch (which) { case 0: // ListView mType = SIMPLE; mRecyclerView.setAdapter(mAdapter); mRecyclerView.setLayoutManager(new LinearLayoutManager( MainActivity.this, LinearLayoutManager.VERTICAL, false)); break; case 1: // Vertical GridView mType = SIMPLE; mRecyclerView.setAdapter(mAdapter); mRecyclerView .setLayoutManager(new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL)); break; case 2: // Horizontal GridView mType = SIMPLE; mRecyclerView.setAdapter(mAdapter); mRecyclerView .setLayoutManager(new StaggeredGridLayoutManager(5, StaggeredGridLayoutManager.HORIZONTAL)); break; case 3: // Staggered mType = STAGGERED; mRecyclerView.setAdapter(mStaggeredAdapter); mRecyclerView .setLayoutManager(new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL)); break; default: break; } } }; String[] menu = { "ListView", "Vertical GridView", "Horizontal GridView", "Staggered" }; mBuilder = new AlertDialog.Builder(this).setTitle("Menu").setItems( menu, mListener); } private void addListener() { mAddBtn.setOnClickListener(this); mDeleteBtn.setOnClickListener(this); mMenuBtn.setOnClickListener(this); mAdapter.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemLongClick(View view, int position) { mAdapter.deleteItem(position); Toast.makeText(MainActivity.this, "long click:" + position, Toast.LENGTH_SHORT).show(); } @Override public void onItemClick(View view, int position) { Toast.makeText(MainActivity.this, "click:" + position, Toast.LENGTH_SHORT).show(); } }); mStaggeredAdapter.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemLongClick(View view, int position) { mStaggeredAdapter.deleteItem(position); Toast.makeText(MainActivity.this, "long click:" + position, Toast.LENGTH_SHORT).show(); } @Override public void onItemClick(View view, int position) { Toast.makeText(MainActivity.this, "click:" + position, Toast.LENGTH_SHORT).show(); } }); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.id_add: if (mType == SIMPLE) { mAdapter.addItem(1); } else { mStaggeredAdapter.addItem(1); } break; case R.id.id_delete: if (mType == SIMPLE) { mAdapter.deleteItem(1); } else { mStaggeredAdapter.deleteItem(1); } break; case R.id.id_menu: mBuilder.show(); break; default: break; } }}
代码中有两个Adapter,分别是SimpleAdapter和StaggeredAdapter,后一个Adapter主要是给瀑布流布局使用,因为其item的高度是随机的。
SimpleAdapter继承RecyclerView中的内置Adapter, 并且RecyclerView中强制用户使用ViewHolder,用户需要写一个RecyclerView中的ViewHolder:
package com.example.testrecyclerview;import java.util.ArrayList;import java.util.List;import android.content.Context;import android.support.v7.widget.RecyclerView;import android.support.v7.widget.RecyclerView.ViewHolder;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.view.View.OnLongClickListener;import android.view.ViewGroup;import android.widget.TextView;public class SimpleAdapter extends RecyclerView.Adapter{ protected List mList; protected Context mContext; protected LayoutInflater mInflater; protected OnItemClickListener mClickListener; public SimpleAdapter(Context context, List list){ this.mContext = context; this.mInflater = LayoutInflater.from(context); if (list != null){ this.mList = list; }else { mList = new ArrayList (); } } @Override public int getItemCount() { // TODO Auto-generated method stub return mList.size(); } @Override public void onBindViewHolder(final SimpleViewHolder holder, final int position) { holder.mTextView.setText(mList.get(position)); if (mClickListener != null){ holder.itemView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { int pos = holder.getPosition(); mClickListener.onItemClick(holder.itemView, pos); } }); holder.itemView.setOnLongClickListener(new OnLongClickListener() { @Override public boolean onLongClick(View v) { int pos = holder.getPosition(); mClickListener.onItemLongClick(holder.itemView, pos); return false; } }); } } @Override public SimpleViewHolder onCreateViewHolder(ViewGroup parent, int arg1) { View view = mInflater.inflate(R.layout.item_recyclerview, parent, false); SimpleViewHolder holder = new SimpleViewHolder(view); return holder; } public void addItem(int position){ mList.add(position, "Insert one"); notifyItemInserted(position); } public void deleteItem(int position){ mList.remove(position); notifyItemRemoved(position); } public void setOnItemClickListener(OnItemClickListener listener){ this.mClickListener = listener; } class SimpleViewHolder extends ViewHolder{ TextView mTextView; public SimpleViewHolder(View view) { super(view); mTextView = (TextView) view.findViewById(R.id.id_num); } } public interface OnItemClickListener{ void onItemClick(View view, int position); void onItemLongClick(View view, int position); }}
瀑布流的Adapter,继承自SimpleAdapter:
package com.example.testrecyclerview;import java.util.ArrayList;import java.util.List;import com.example.testrecyclerview.SimpleAdapter.SimpleViewHolder;import android.content.Context;import android.support.v7.widget.RecyclerView;import android.support.v7.widget.RecyclerView.ViewHolder;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.view.View.OnClickListener;import android.view.View.OnLongClickListener;import android.view.ViewGroup.LayoutParams;import android.widget.TextView;public class StaggeredAdapter extends SimpleAdapter { protected ListmHeights; public StaggeredAdapter(Context context, List list){ super(context, list); mHeights = new ArrayList (); for (int i=0; i
需要注意的是,RecyclerView并没有实现点击事件,这需要我们自己写接口并去调用,这一点在Adapter中已经有体现