网格视图GridView

package com.example.revrse.gridview;

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

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import com.example.revrse.R;

public class GridViewActivity extends AppCompatActivity {

    private GridView mGv;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gridview);

        mGv=(GridView)findViewById(R.id.gv);
    }
}

package com.example.revrse.gridview;

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

import com.example.revrse.R;

public class MyGridViewActivity extends BaseAdapter {

    private Context mContext;
    private LayoutInflater mLayoutInflater;
    public MyGridViewActivity(Context context){
        this.mContext=context;
        mLayoutInflater =LayoutInflater.from(context);
    }
    @Override
    public int getCount() {
        return 10;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

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

    static class ViewHolder{
        public ImageView imageView;
        public TextView textView;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder=null;
        if(convertView==null) {
            convertView = mLayoutInflater.inflate(R.layout.activity_gridview_item,null);
            holder=new ViewHolder();
            holder.imageView=convertView.findViewById(R.id.iv_grid);
            holder.textView=convertView.findViewById(R.id.tv_title);
            convertView.setTag(holder);
        }
        else{
            holder=(ViewHolder)convertView.getTag();
        }
        holder.textView.setText("加油");
        return convertView;
    }
}

<?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="15dp">

    <GridView
        android:id="@+id/gv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:numColumns="3"
        android:horizontalSpacing="10dp"
        android:verticalSpacing="10dp"/>

</LinearLayout>

<?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:gravity="center_horizontal">

    <ImageView
        android:id="@+id/iv_grid"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:scaleType="fitCenter"
        android:background="#899000"/>

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:text="Come on!"
        android:gravity="center"
        android:textColor="#89178619"/>

</LinearLayout>