Android RecyclerView选择多个item Android RecyclerView选择多个item的实现代码

时间:2021-03-24 ShouCeng 人气:1

想了解Android RecyclerView选择多个item的实现代码的相关内容吗，ShouCeng在本文为您仔细讲解Android RecyclerView选择多个item的相关知识和一些Code实例，欢迎阅读和指正，我们先划重点：Android,RecyclerView,item，下面大家一起来学习吧。

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。

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