这是一个 GridView 和 adapter 的学习demo！！
目标，做一个类似这样的表格。

代码如下：
MainActivity：

package com.example.test20201219_2;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.GridView;

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

public class MainActivity extends AppCompatActivity {

    private GridView mGridView;
    private ProvinceAdapter mProvinceAdapter;
    private String[] provinceNames = new String[]{"北京"," " ,"上海", "广东", "广西", "天津", "重庆", "湖北", "湖南", "河北", "河南", "山东"};


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        mGridView = (GridView) this.findViewById(R.id.grid_view);
        List<ProvinceBean> provinceBeanList = new ArrayList<>();
        for (int i = 0; i < provinceNames.length; i++) {
            ProvinceBean provinceBean = new ProvinceBean();
            provinceBean.setName(provinceNames[i]);
            //provinceBean.setColor(bgColor[i]);
            provinceBeanList.add(provinceBean);
        }
        mProvinceAdapter = new ProvinceAdapter(this, provinceBeanList);
        /**
         * mProvinceAdapter是数据适配器（有this与数据的参数）
         */
        mGridView.setAdapter(mProvinceAdapter);
        /**
         * mGridView与数据适配器关联
         * 数据适配器的数据就一个个按照次序放到Grid的格子里面
         * 从左往右，从上往下
         */
    }

}

ProvinceAdapter.java

package com.example.test20201219_2;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.example.test20201219_2.R;

import java.util.List;

public class ProvinceAdapter extends BaseAdapter {

    private List<ProvinceBean> provinceBeanList;
    private LayoutInflater layoutInflater;

    public ProvinceAdapter(Context context, List<ProvinceBean> provinceBeanList) {
        this.provinceBeanList = provinceBeanList;
        layoutInflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return provinceBeanList.size();
    }

    @Override
    public Object getItem(int position) {
        return provinceBeanList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        if (convertView == null) {
            convertView = layoutInflater.inflate(R.layout.province_grid_view_item_layout, null);
            holder = new ViewHolder();
            holder.text = (TextView) convertView.findViewById(R.id.text);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        ProvinceBean provinceBean = provinceBeanList.get(position);
        if (provinceBean != null) {
            holder.text.setText(provinceBean.getName());
            holder.text.setBackgroundResource(provinceBean.getColor());
        }
        return convertView;
    }

    class ViewHolder {
        TextView text;
    }

}

ProvinceBean:

package com.example.test20201219_2;

class ProvinceBean {
    private String name;
    private int color;

    public ProvinceBean(String name, int color) {
        this.name = name;
        this.color = color;
    }

    public ProvinceBean() {

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getColor() {
        return color;
    }

    public void setColor(int color) {
        this.color = color;
    }
}

main_xml:

<?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.example.sunxiaodong.androidgridview.MainActivity">-->


    <GridView
        android:id="@+id/grid_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:columnWidth="90dp"
        android:gravity="center"
        android:horizontalSpacing="10dp"
        android:numColumns="auto_fit"
        android:stretchMode="columnWidth"
        android:verticalSpacing="10dp" />

</RelativeLayout>

province_xml:

<?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">

    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="12"
        android:textSize="18sp" />
</LinearLayout>