带有自定义分割线的recyclerview

最新推荐文章于 2022-02-15 15:22:23 发布

原创最新推荐文章于 2022-02-15 15:22:23 发布 · 152 阅读

0 ·

CC 4.0 BY-SA版权

Android 专栏收录该内容

36 篇文章

订阅专栏

本文详细介绍了如何在Android应用中使用RecyclerView并自定义其分割线。通过创建自定义的DividerItemDecoration类，可以实现水平或垂直的分割线，并应用于RecyclerView的列表项之间，提升界面美观度。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

效果图：

activity_main:

package com.example.lenovo.my_recyclerview;

import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private HomeAdapter mHomeAdapter;
    private List<String> mList;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         init();
        RecyclerView mRecyclerView=this.findViewById(R.id.id_recyclerview);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        //设置item增加和删除的动画
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());
        mHomeAdapter=new HomeAdapter(this,mList);
        mRecyclerView.addItemDecoration(new DividerItemDecoration
                (MainActivity.this,DividerItemDecoration.VERTICAL_LIST));
        mRecyclerView.setAdapter(mHomeAdapter);
    }

    private void init() {
        mList=new ArrayList<String>();
        for(int i=0;i<50;i++){
            mList.add("content"+i);
        }
    }

}

HomeAdapter.java

package com.example.lenovo.my_recyclerview;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> {
    private List<String> mList;
    private Context mContext;
    public HomeAdapter(Context mContext,List<String> mList){
       this.mContext=mContext;
       this.mList=mList;

    }
    public HomeAdapter(){
        mList=new ArrayList<String>();
        for(int i=1;i<=50;i++){
            mList.add(String.valueOf(i));
        }
    }
    public void removeData(int position){
        mList.remove(position);
        notifyItemRemoved(position);

    }
    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        MyViewHolder holder=new MyViewHolder(LayoutInflater.from(mContext).
                inflate(R.layout.item_recycler,parent,false));
        return holder;
    }

    @Override
    public void onBindViewHolder(final MyViewHolder holder, final int position) {
          holder.tv.setText(mList.get(position));
    }

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

    public class MyViewHolder extends RecyclerView.ViewHolder {
        TextView tv;
        public MyViewHolder(@NonNull View View) {

            super(View);
            tv= View.findViewById(R.id.tv_item);
        }
    }
}

item_recycler.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:background="@android:color/white"
    android:layout_height="wrap_content"
    >
    <TextView
        android:id="@+id/tv_item"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:gravity="center"
        android:text="moon"/>
</FrameLayout>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
    android:id="@+id/id_recyclerview"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

</android.support.v7.widget.RecyclerView>

</RelativeLayout>

DividerItemIcomodation.java

package com.example.lenovo.my_recyclerview;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;

public class DividerItemDecoration extends RecyclerView.ItemDecoration {
    public 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();
        try {
            setOrientation(orientation);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }

    public void setOrientation(int orientation) throws IllegalAccessException {
        if(orientation!=HORIZONTAL_LIST&&orientation!=VERTICAL_LIST){
            throw new IllegalAccessException("invalid orientation");

        }
        mOrientation=orientation;
    }

    @Override
    public void onDraw(@NonNull Canvas c, @NonNull RecyclerView parent) {
        if(mOrientation==VERTICAL_LIST){
            drawVertical(c,parent);
        }else{
            drawHorizonal(c,parent);
        }
    }

    public 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++){
            //在集合中返回指定位置的视图
            final View child=parent.getChildAt(i);
            //布局参数
            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);
        }
    }

    public void drawHorizonal(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.getIntrinsicWidth();
            mDivider.setBounds(left,top,right,bottom);
            mDivider.draw(c);
        }
    }

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