模仿网易新闻客户端阅读偏好的频道选择，先看实现的页面：
直接上代码：
import android.content.res.Resources;import android.content.res.TypedArray;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.DefaultItemAnimator;import android.support.v7.widget.GridLayoutManager;import android.support.v7.widget.RecyclerView;import android.support.v7.widget.helper.ItemTouchHelper;import android.util.Log;import android.util.SparseBooleanArray;import android.view.View;import java.util.ArrayList;import java.util.Collections;import java.util.List;public class RecyclerViewActivity extends AppCompatActivity { private RecyclerView recycler; private RecyclerAdapter mAdapter; private List<PreferCustomizableChannel> channels = new ArrayList<>(); private List<PreferCustomizableChannel> channelsSelected; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_recycler_view_acitivity); initData(); initUI(); findViewById(R.id.resultBTN).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int lens = channelsSelected.size(); for (int i =0 ; i < lens; i++) { PreferCustomizableChannel customizableChannel = channelsSelected.get(i); if (customizableChannel.isSelected()) { Log.i("RecyclerViewActivity", "onClick: "+customizableChannel.toString()); } } } }); } private void initData() { Resources resources = getResources(); TypedArray array = resources.obtainTypedArray(R.array.prefer_channel_icon); int len = array.length(); String[] name = resources.getStringArray(R.array.prefer_channel_name); for (int i = 0; i < len; i++) { PreferCustomizableChannel customizableChannel = new PreferCustomizableChannel(); customizableChannel.setChannel(name[i]); customizableChannel.setResId(array.getResourceId(i, 0)); customizableChannel.setSelected(false); customizableChannel.setId(i * 100); channels.add(customizableChannel); } array.recycle(); channelsSelected = channels; } private void initUI() { recycler = (RecyclerView) findViewById(R.id.recycler); final GridLayoutManager manager = new GridLayoutManager(this, 3); recycler.setLayoutManager(manager); recycler.setHasFixedSize(true); recycler.setItemAnimator(new DefaultItemAnimator()); mAdapter = new RecyclerAdapter(RecyclerViewActivity.this, channels); recycler.setAdapter(mAdapter); mAdapter.setClickListener(new OnRecyclerViewItemClickListener() { @Override public void onItemClick(View view, int position) { SparseBooleanArray selecteds = mAdapter.getSelectedItem(); int len = channels.size(); for (int i = 0; i < len; i++) { if (selecteds.get(i)) { channelsSelected.get(position).setSelected(true); } } } }); }}
布局文件RecyclerView横竖都是“match_parent”,否则在点击的时候gridView会自动上滑一段距离。
适配器的实现：
import android.support.v7.widget.RecyclerView;import android.util.SparseBooleanArray;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.RelativeLayout;import android.widget.TextView;import com.entity.PreferCustomizableChannel;import com.listener.OnRecyclerItemClickListener;import java.util.List;import butterknife.BindView;import butterknife.ButterKnife;public class PreferChannelAdapter extends RecyclerView.Adapter<PreferChannelAdapter.PreferChannelHolder>{ private List<PreferCustomizableChannel> lists; private OnRecyclerItemClickListener listener; private SparseBooleanArray selectLists = new SparseBooleanArray(); public PreferChannelAdapter() { } public void setDatas(List<PreferCustomizableChannel> lists) { this.lists = lists; notifyDataSetChanged(); } public void setOnItemClickListener(OnRecyclerItemClickListener listener) { this.listener = listener; } @Override public PreferChannelHolder onCreateViewHolder(ViewGroup parent, int viewType) { View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.prefer_channel_item, null); return new PreferChannelHolder(view); } @Override public void onBindViewHolder(final PreferChannelHolder holder, final int position) { PreferCustomizableChannel channelItem = lists.get(position); holder.channelItemTV.setText(channelItem.getChannel()); holder.channelItemImg.setImageResource(channelItem.getResId()); if (!selectLists.get(position)) { holder.selectedMarkImg.setVisibility(View.GONE); } else { holder.selectedMarkImg.setVisibility(View.VISIBLE); } holder.preferChannelItemLayout.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { if (holder.selectedMarkImg.getVisibility() == View.GONE) { holder.selectedMarkImg.setVisibility(View.VISIBLE); selectLists.put(position, true); } else if (holder.selectedMarkImg.getVisibility() == View.VISIBLE){ holder.selectedMarkImg.setVisibility(View.GONE); selectLists.put(position, false); } listener.onRecyclerClick(position); } }); } @Override public int getItemCount() { return lists.size(); } public class PreferChannelHolder extends RecyclerView.ViewHolder { @BindView(R.id.preferChannelItemLayout) RelativeLayout preferChannelItemLayout; @BindView(R.id.channelItemTV) TextView channelItemTV; @BindView(R.id.channelItemImg) ImageView channelItemImg; @BindView(R.id.selectedMarkImg) ImageView selectedMarkImg; public PreferChannelHolder(View itemView) { super(itemView); ButterKnife.bind(this, itemView); } } public SparseBooleanArray getSelectedItem() { return selectLists; }}
顺便把item的布局也贴出来吧：
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/preferChannelItemLayout" android:gravity="center" android:layout_gravity="center" android:layout_marginTop="10dp" android:layout_width="wrap_content" android:layout_height="wrap_content"> <!--android:gravity="center" android:layout_gravity="center"--> <ImageView android:id="@+id/channelItemImg" android:scaleType="centerInside" android:layout_width="68dp" android:layout_height="wrap_content"/> <TextView android:id="@+id/channelItemTV" android:gravity="center" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:layout_marginBottom="20dp" android:layout_marginTop="8dp" android:layout_below="@id/channelItemImg" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <ImageView android:id="@+id/selectedMarkImg" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerVertical="true" android:visibility="gone" android:layout_alignRight="@id/channelItemImg" android:src="@mipmap/prefer_selected"/></RelativeLayout>
其他注意的地方：
SpareBooleanArrary.size()返回的是已经设置为true的长度，比如选择了一个则返回1，选择了10则返回10，但在选择了10后去掉一个的时候，size()返回的并不是9，而依然是10，这点注意，所以在遍历的时候并没有使用使用size()取长度。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
我们一直在旅行，一直在等待某个人可以成为我们旅途的伴侣，
