RecyclerView实现线性布局以及网格布局的简单使用

本文简单使用RecyclerView实现线性布局以及网格布局
在做这一切工作之前，要在app.gradle中添加依赖

dependencies {
    implementation 'com.android.support:appcompat-v7:23.2.1'
}

之后在布局文件MainActivity中添加一个recyclerview，

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="horizontal">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

接着创建一个layout文件，在其中放入一个TextView用于显示文字

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="100dp"
    android:layout_height="60dp">

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="TextView" />
</LinearLayout>

这里的线性布局的属性将影响之后整体布局中的文字属性，如长度、宽度等
接着是MainActivity文件的代码：

package com.game.recycler;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
RecyclerView recyclerView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //对recyclerview进行引用
        recyclerView = (RecyclerView)findViewById(R.id.recyclerview);
        //配置显示规则。包含三种：LinearLayoutManager（线性）、GridLayoutManager（网格）、StaggeredGridLayoutManager（瀑布流）
        recyclerView.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.HORIZONTAL,false));
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        //recyclerView.setLayoutManager(new GridLayoutManager(this,3));
        MyAdapter myAdapter = new MyAdapter();
        recyclerView.setAdapter(myAdapter);
    }
    private class MyAdapter extends RecyclerView.Adapter{
        @NonNull
        @Override

        public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            //inflate中第二和第三参数设置为null也行，但要使得布局之间间距等达到布局设定中的效果，就必须添加parent和false
            // View itemview = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_view,null);
            View itemview = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_view,parent,false);
            MyViewHolder viewHolder = new MyViewHolder(itemview);
            return viewHolder;
        }

        @Override
        public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
            ((MyViewHolder) holder ).textView.setText("编号:"+ position);
        }
        String[]dataArr = {
                "第0项","第1项","第2项",
                "第0项","第1项","第2项",
                "第0项","第1项","第2项",
                "第0项","第1项","第2项",
                "第0项","第1项","第2项"
        };
        @Override
        public int getItemCount() {
            return dataArr.length;
        }
        private  class MyViewHolder extends RecyclerView.ViewHolder{
            private TextView textView;
            public MyViewHolder(View itemview){
                super(itemview);
                textView=itemview.findViewById(R.id.textView);
            }
        }
    }
}

一下两个即为不同的显示布局的设定，调用的recyclerview的setLayoutManager方法来设置

 recyclerView.setLayoutManager(layoutManager);//显示的线性布局
 recyclerView.setLayoutManager(new GridLayoutManager(this,3));//显示的网格布局，3为每行显示的个数