RecyclerView控件的使用

其他 2018-10-13 08:41:17 阅读次数: 0
版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/Ericpengjun/article/details/51995755

Recyclerview已经推出很长时间了，近段时间工作不是很忙，就把以前所有项目的ListView都更新到 Recyclerview了，功能蛮强大的，具体的就不多说了，在这里就给大家分享下实际运用中的方法吧。

在build.gradle文件中添加依赖包（android studio开发工具）

 compile 'com.android.support:recyclerview-v7:24.1.1'

main_layout布局文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.eric.recyclerviewdemo.MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</RelativeLayout>

item_layout布局文件：

<?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="56dp">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/item_text"
        android:padding="10dp"
        android:textSize="18sp"/>

</LinearLayout>

MainActivity代码：

public class MainActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private DemoAdapter adapter;
    private List<String> mDatas;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //创建对象
        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        //准备数据
        mDatas = new ArrayList<>();
        for (int i = 0; i < 50; i++) {
            mDatas.add("RecyclerView item"+i);
        }

        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        //设置布局管理器
        recyclerView.setLayoutManager(layoutManager);
        //设置垂直布局方式（系统默认也是垂直的）
        layoutManager.setOrientation(OrientationHelper.VERTICAL);
        //设置适配器adapter
        adapter = new DemoAdapter(this,mDatas);
        //设置分隔线
        recyclerView.addItemDecoration( new DividerItemDecoration(this,DividerItemDecoration.VERTICAL_LIST));
        recyclerView.setAdapter(adapter);
    }
}

DemoAdapter代码：

public class DemoAdapter extends RecyclerView.Adapter {
    private Context context;
    private List<String> mData;

    public DemoAdapter(Context context, List<String> datas) {
        this.context = context;
        this.mData = datas;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.item_layout,parent,false);
        return new MyViewHolder(view);
    }

    private class MyViewHolder extends RecyclerView.ViewHolder {
        TextView tv;

        public MyViewHolder(View itemView) {
            super(itemView);
            tv = (TextView) itemView.findViewById(R.id.item_text);
        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        MyViewHolder myHolder = (MyViewHolder) holder;
        myHolder.tv.setText(mData.get(position));
    }

    @Override
    public int getItemCount() {
        return mData.size();
    }

}

DividerItemDecoration代码：

public class DividerItemDecoration extends RecyclerView.ItemDecoration{
    private static final int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };
    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
    private Drawable mDivider;
    private int mOrientation;
    public DividerItemDecoration(Context context, int orientation){
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }

    private void setOrientation(int orientation) {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST){
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST){
            drawVertical(c,parent);
        }else {
            drawHorizontal(c,parent);
        }
    }
    //垂直分割线
    private void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++){
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
    //水平分割线
    private void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST){
            outRect.set(0,0,0,mDivider.getIntrinsicHeight());
        }else {
            outRect.set(0,0,mDivider.getIntrinsicWidth(),0);
        }
    }
}

运行效果：
这里写图片描述

给RecyclerView的Item添加点击事件，在DemoAdapter修改代码如下：

public class DemoAdapter extends RecyclerView.Adapter {
    private Context context;
    private List<String> mData;
    private OnItemCLickListener myItemCLickListener;

    //创建item点击事件的接口
    public interface OnItemCLickListener{
        void onClick(View view,int position);
    }

    //创建外部调用的回调方法
    public void setItemCLickListener(OnItemCLickListener itemCLickListener) {
        this.myItemCLickListener = itemCLickListener;
    }

    public DemoAdapter(Context context, List<String> datas) {
        this.context = context;
        this.mData = datas;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.item_layout,parent,false);
        return new MyViewHolder(view);
    }

    class MyViewHolder extends RecyclerView.ViewHolder {
        TextView tv;

        public MyViewHolder(View itemView) {
            super(itemView);
            tv = (TextView) itemView.findViewById(R.id.item_text);
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    myItemCLickListener.onClick(view,getPosition());
                }
            });
        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        MyViewHolder myHolder = (MyViewHolder) holder;
        myHolder.tv.setText(mData.get(position));
    }

    @Override
    public int getItemCount() {
        return mData.size();
    }

}

MainActivity实现点击事件方法：

 //实现点击事件
        adapter.setItemCLickListener(new DemoAdapter.OnItemCLickListener() {
            @Override
            public void onClick(View view, int position) {
                Toast.makeText(MainActivity.this, "你点击了"+mDatas.get(position), Toast.LENGTH_SHORT).show();
            }
        });

实现 item 点击选中变色的效果，在DemoAdapter增加以下代码：

public class DemoAdapter extends RecyclerView.Adapter {
    private Context context;
    private List<String> mData;
    private int selectPosition = -1； //选中的位置
    private OnItemCLickListener myItemCLickListener;

    //创建item点击事件的接口
    public interface OnItemCLickListener{
        void onClick(View view,int position);
    }

    //创建外部调用的回调方法
    public void setItemCLickListener(OnItemCLickListener itemCLickListener) {
        this.myItemCLickListener = itemCLickListener;
    }

    //定义一个setPosition的方法供Activity调用获取position的值
    public void setSelectPosition(int selectPosition) {
        this.selectPosition = selectPosition;
    }

    public DemoAdapter(Context context, List<String> datas) {
        this.context = context;
        this.mData = datas;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.item_layout,parent,false);
        return new MyViewHolder(view);
    }

    class MyViewHolder extends RecyclerView.ViewHolder {
        TextView tv;

        public MyViewHolder(View itemView) {
            super(itemView);
            tv = (TextView) itemView.findViewById(R.id.item_text);
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    myItemCLickListener.onClick(view,getPosition());
                }
            });
        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        MyViewHolder myHolder = (MyViewHolder) holder;
        myHolder.tv.setText(mData.get(position));
        //判断当前点击的position并改变颜色
        if (selectPosition == position){
            vh.tv.setBackgroundColor(Color.RED);
        }else {
            vh.tv.setBackgroundColor(Color.TRANSPARENT);
        }
    }

    @Override
    public int getItemCount() {
        return mData.size();
    }

}

MainActivity增加实现方法：

//实现点击事件
        adapter.setItemCLickListener(new DemoAdapter.OnItemCLickListener() {
            @Override
            public void onClick(View view, int position) {
                Toast.makeText(MainActivity.this, "你点击了"+mDatas.get(position), Toast.LENGTH_SHORT).show();
                adapter.setSelectPosition(position);
                adapter.notifyDataSetChanged();
            }
        });

运行效果就不贴出来了，小伙伴们自己去试试吧！！！喜欢的请支持我一下！(￣▽￣*)

猜你喜欢

转载自blog.csdn.net/Ericpengjun/article/details/51995755
今日推荐
周排行
vue + echart +map中国地图，省市地图，区县地图
spring boot2 (31)-cors跨域请求
『学习资料推荐』299元买的微信营销资料打包
个人学习卷积神经网络的疑惑解答
网络工程师-软考
模拟人生4 春夏秋冬、星梦起飞版更新下载方法以及常见问题
python关于对象的字符串显示str和repr以及
奇怪的session混乱问题
【3】分治法（divide-and-conquer）
Java项目开发成绩管理系统（九） 各模块实现信息修改
每日归档
更多
2024-08-07(0)
2024-08-06(0)
2024-08-05(0)
2024-08-04(0)
2024-08-03(0)
2024-08-02(0)
2024-08-01(0)
2024-07-31(0)
2024-07-30(0)
2024-07-29(0)

代码天地 © 2018 codetd.com

境外服务器   最新电视剧2022