RecyclerView实现的一些功能

来源：互联网发布：淘宝众筹的整体销量编辑：程序博客网时间：2024/06/05 17:46

前言

RecyclerView是Android 5.0 新出的一个控件，可以完全代替之前的ListView，当然功能各方面也比较强大，今天来看看实际项目中可能会遇到的一些与RecyclerView相关的功能实现。

效果图一

条目单选并监听

这里写图片描述

代码

MainActivity

public class MainActivity extends AppCompatActivity{    private List<String> datas;    private RecyclerView recyclerView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        recyclerView = (RecyclerView) findViewById(R.id.recyview);        initData();        final CustomAdapter adapter = new CustomAdapter(this,datas);        GridLayoutManager manager = new GridLayoutManager(this,2);        recyclerView.setLayoutManager(manager);        recyclerView.setAdapter(adapter);       adapter.setOnItemClickListener(new CustomAdapter.OnRecyclerViewItemClickListener() {           @Override           public void onItemClick(View view, String data, int position) {//data为内容，position为点击的位置              ToastUtil.getShortToastByString(MainActivity.this,"data: "+data+",position: "+position);           }       });    }    public void initData() {        datas = new ArrayList<>();        for (int i = 'A'; i < 'K'; i++) {            datas.add(""+(char)i);        }    }}

MainActivity布局文件

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    >   <android.support.v7.widget.RecyclerView       android:id="@+id/recyview"       android:layout_width="match_parent"       android:layout_height="match_parent">   </android.support.v7.widget.RecyclerView></LinearLayout>

CustomAdapter

public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.MyViewHolder> {    private Context context;    private List<String> data;    private OnRecyclerViewItemClickListener mOnItemClickListener;    private MyViewHolder holder;    private int layoutPosition;    public  interface OnRecyclerViewItemClickListener {        void onItemClick(View view , String data,int position);    }    public CustomAdapter(Context context, List<String> data){        this.context = context;        this.data = data;    }    public void setOnItemClickListener(OnRecyclerViewItemClickListener listener) {        this.mOnItemClickListener = listener;    }    @Override    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        View itemView = View.inflate(context, R.layout.item_view, null);        holder = new MyViewHolder(itemView);        return holder;    }    @Override    public void onBindViewHolder(final MyViewHolder holder, final int position) {        holder.textView.setText(data.get(position));        holder.itemView.setTag(data.get(position));        holder.itemView.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                //获取当前点击的位置                layoutPosition = holder.getLayoutPosition();                notifyDataSetChanged();                mOnItemClickListener.onItemClick(holder.itemView, (String) holder.itemView.getTag(), layoutPosition);            }        });        //更改状态        if(position == layoutPosition){            holder.textView.setBackgroundResource(R.drawable.bg_unselect);            holder.textView.setTextColor(Color.RED);        }else{            holder.textView.setBackgroundResource(R.drawable.bg_select);            holder.textView.setTextColor(Color.BLUE);        }    }    @Override    public long getItemId(int position) {        return position;    }    @Override    public int getItemCount() {        return data.size();    }    class MyViewHolder extends RecyclerView.ViewHolder {        private final TextView textView;        public MyViewHolder(View itemView) {            super(itemView);            textView = (TextView) itemView.findViewById(R.id.tv_item);        }    }}

条目布局

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical" android:layout_width="match_parent"    android:layout_height="match_parent"    android:padding="5dp"    >    <TextView        android:id="@+id/tv_item"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:textSize="20sp"        android:gravity="center"        android:background="@drawable/bg_unselect"        /></LinearLayout>

条目选中和未选中的背景

//bg_unselect<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android">            <solid android:color="@android:color/holo_orange_dark"/>            <corners android:radius="8dp"/></shape>

//bg_select<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android">        <solid android:color="@android:color/holo_blue_light"/>        <corners android:radius="8dp"/></shape>

最后是一个连续不重复弹Toast的工具类

public class ToastUtil {    private static Context context = null;    private static Toast toast = null;    public static void getShortToast(Context context,int retId){        if (toast == null) {            toast = Toast.makeText(context, retId, Toast.LENGTH_SHORT);        } else {            toast.setText(retId);            toast.setDuration(Toast.LENGTH_SHORT);        }        toast.show();    }    public static void getShortToastByString(Context context,String hint){        if (toast == null) {            toast = Toast.makeText(context, hint, Toast.LENGTH_SHORT);        } else {            toast.setText(hint);            toast.setDuration(Toast.LENGTH_SHORT);        }        toast.show();    }    public static void getLongToast(Context context,int retId){        if (toast == null) {            toast = Toast.makeText(context, retId, Toast.LENGTH_LONG);        } else {            toast.setText(retId);            toast.setDuration(Toast.LENGTH_LONG);        }        toast.show();    }    public static void getLongToastByString(Context context, String hint){        if (toast == null) {            toast = Toast.makeText(context, hint, Toast.LENGTH_LONG);        } else {            toast.setText(hint);            toast.setDuration(Toast.LENGTH_LONG);        }        toast.show();    }}

如果刚进来不想选中第一个条目，可以定一个标记

 //更改状态        if(position == layoutPosition&&!isFirstEnter){                holder.textView.setBackgroundResource(R.drawable.bg_unselect);                holder.textView.setTextColor(Color.RED);        }else{            holder.textView.setBackgroundResource(R.drawable.bg_select);            holder.textView.setTextColor(Color.BLUE);            isFirstEnter = false;        }

效果图二

设置条目之间的间距

这里写图片描述

public class MainActivity extends AppCompatActivity{    private RecyclerView recyclerView;    private List<String> datas = new ArrayList<>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        recyclerView = (RecyclerView) findViewById(R.id.rv_content);        initData();        RvContentAdapter adapter = new RvContentAdapter(this,datas);        GridLayoutManager manager = new GridLayoutManager(this,3);        recyclerView.setLayoutManager(manager);        SpaceItemDecoration itemDecoration = new SpaceItemDecoration(10,20);        recyclerView.addItemDecoration(itemDecoration);        recyclerView.setAdapter(adapter);    }    public void initData() {        datas = new ArrayList<>();        for (int i = 'A'; i < 'Z'; i++) {            datas.add(""+(char)i);        }    }}

public class SpaceItemDecoration extends RecyclerView.ItemDecoration {    private int horizontalspace;    private int verticalspace;    public SpaceItemDecoration(int horizontalspace,int verticalspace) {        this.horizontalspace = horizontalspace;        this.verticalspace = verticalspace;    }    @Override    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {        //不是第一个的格子都设一个左边和底部的间距        outRect.left = horizontalspace;        outRect.bottom = verticalspace;//        //由于每行都只有3个，所以第一个都是3的倍数，把左边距设为0        if (parent.getChildLayoutPosition(view) %3==0) {            outRect.left = 0;        }        int childCount = parent.getChildCount();    }}

效果图三

条目多选并且监听

这里写图片描述

public class RvContentAdapter extends RecyclerView.Adapter<RvContentAdapter.MyViewHolder>{    private Context context;    private List<String> contentDatas;    public OnItemSelectedListener mListener;    private boolean[] isSelected ;    public interface OnItemSelectedListener{        void onItemSelect(int position);    }    public void setOnItemSelectedListener(OnItemSelectedListener listener){        mListener = listener;    }    public RvContentAdapter(Context context, List<String> data){        this.context = context;        this.contentDatas = data;        isSelected = new boolean[data.size()];        for (int i = 0; i < data.size(); i++) {            isSelected[i] = false;        }    }    @Override    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        return new MyViewHolder(View.inflate(context,R.layout.list_item_layout,null));    }    @Override    public void onBindViewHolder(MyViewHolder holder, final int position) {        holder.tvTitle.setText(contentDatas.get(position));//标题        holder.linearLayout.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                isSelected[position]=isSelected[position]==true?false:true;                notifyDataSetChanged();                mListener.onItemSelect(position);            }        });        if(isSelected[position] == true){            holder.linearLayout.setBackgroundResource(R.drawable.bg_item_select);        }else{            holder.linearLayout.setBackgroundResource(R.drawable.bg_item_unselect);        }    }    @Override    public int getItemCount() {        return contentDatas.size();    }    class MyViewHolder extends RecyclerView.ViewHolder{        private final TextView tvTitle;        private final LinearLayout linearLayout;        public MyViewHolder(View itemView) {            super(itemView);            tvTitle = (TextView) itemView.findViewById(R.id.tv_item);            linearLayout = (LinearLayout) itemView.findViewById(R.id.ll_parent);        }    }}

然后我们在Activity中调用下面的方法设置回调监听

  adapter.setOnItemSelectedListener(new RvContentAdapter.OnItemSelectedListener() {            @Override            public void onItemSelect(int position) {                Toast.makeText(MainActivity.this, datas.get(position), Toast.LENGTH_SHORT).show();            }        });

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