一手遮天 Android

项目地址 https://github.com/webabcd/AndroidDemo
作者 webabcd

一手遮天 Android - view（集合类）: GridView 基础 1

示例如下:

/view/collection/GridViewDemo1.java

/**
 * GridView - 网格控件
 *
 * 本例演示
 * 1、GridView 通过 BaseAdapter 显示数据
 * 2、GridView 通过 numColumns 来指定网格控件的列数（网格列宽会平均分，行高和行数会自适应）
 * 3、其他更多知识点请参见 ListView 的说明（GridView 和 ListView 都继承自 AbsListView）
 */

package com.webabcd.androiddemo.view.collection;

import android.content.Context;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.TextView;

import com.webabcd.androiddemo.R;

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

public class GridViewDemo1 extends AppCompatActivity {

    private GridView mGridView1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_view_collection_gridviewdemo1);

        mGridView1 = findViewById(R.id.gridView1);

        sample();
    }

    private void sample() {
        // 构造数据
        List<MyData> myDataList = new ArrayList<MyData>();
        myDataList.add(new MyData(R.drawable.img_sample_son, "中国", "我是中国"));
        myDataList.add(new MyData(R.drawable.img_sample_son, "美国", "我是美国"));
        myDataList.add(new MyData(R.drawable.img_sample_son, "日本", "我是日本"));
        myDataList.add(new MyData(R.drawable.img_sample_son, "中国2", "我是中国2"));
        myDataList.add(new MyData(R.drawable.img_sample_son, "美国2", "我是美国2"));
        myDataList.add(new MyData(R.drawable.img_sample_son, "日本2", "我是日本2"));

        // 实例化自定义的 BaseAdapter
        MyAdapter myAdapter = new MyAdapter(myDataList, this);
        mGridView1.setAdapter(myAdapter);
    }

    // 自定义实体类
    class MyData {
        private int _logoId;
        private String _name;
        private String _comment;

        public MyData() {
        }

        public MyData(int logoId, String name, String comment) {
            this._logoId = logoId;
            this._name = name;
            this._comment = comment;
        }

        public int getLogoId() {
            return _logoId;
        }

        public String getName() {
            return _name;
        }

        public String getComment() {
            return _comment;
        }

        public void setLogoId(int logoId) {
            this._logoId = logoId;
        }

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

        public void setComment(String comment) {
            this._comment = comment;
        }
    }

    // 自定义 BaseAdapter
    class MyAdapter extends BaseAdapter {

        private List<MyData> _myDataList;
        private Context _context;

        public MyAdapter(List<MyData> myDataList, Context context) {
            this._myDataList = myDataList;
            this._context = context;
        }

        // 需要呈现的 item 的总数
        @Override
        public int getCount() {
            return _myDataList.size();
        }

        // 返回指定索引位置的 item 的对象
        @Override
        public Object getItem(int position) {
            return _myDataList.get(position);
        }

        // 返回指定索引位置的 item 的 id
        @Override
        public long getItemId(int position) {
            return position;
        }

        /*
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View view = LayoutInflater.from(_context).inflate(R.layout.item_view_collection_gridviewdemo1,parent,false);

            ImageView imgLogo = (ImageView) view.findViewById(R.id.imgLogo);
            TextView txtName = (TextView) view.findViewById(R.id.txtName);
            TextView txtComment = (TextView) view.findViewById(R.id.txtComment);

            imgLogo.setBackgroundResource(_myDataList.get(position).getLogoId());
            txtName.setText(_myDataList.get(position).getName());
            txtComment.setText(_myDataList.get(position).getComment());

            return view;
        }
        */

        // 每构造一个 item 就会调用一次 getView() 来获取这个 item 的 view
        // 数据量不大的话就可以像上面那样写，数量大的话则可以像下面这样写
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder holder = null;
            if (convertView == null) {
                convertView = LayoutInflater.from(_context).inflate(R.layout.item_view_collection_gridviewdemo1, parent, false);

                holder = new ViewHolder();
                holder.imgLogo = (ImageView) convertView.findViewById(R.id.imgLogo);
                holder.txtName = (TextView) convertView.findViewById(R.id.txtName);
                holder.txtComment = (TextView) convertView.findViewById(R.id.txtComment);
                convertView.setTag(holder); // 将 holder 保存到 convertView 中
            } else {
                holder = (ViewHolder) convertView.getTag();
            }

            holder.imgLogo.setBackgroundResource(_myDataList.get(position).getLogoId());
            holder.txtName.setText(_myDataList.get(position).getName());
            holder.txtComment.setText(_myDataList.get(position).getComment());

            return convertView;
        }

        class ViewHolder {
            ImageView imgLogo;
            TextView txtName;
            TextView txtComment;
        }
    }
}

/layout/activity_view_collection_gridviewdemo1.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"
    android:orientation="vertical">

    <!--
        numColumns - 指定网格控件的列数（网格列宽会平均分，行高和行数会自适应）
    -->
    <GridView
        android:id="@+id/gridView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:numColumns="2" />

</LinearLayout>

/layout/item_view_collection_gridviewdemo1.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"
    android:paddingLeft="10dp"
    android:orientation="horizontal">

    <ImageView
        android:id="@+id/imgLogo"
        android:layout_width="64dp"
        android:layout_height="64dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:id="@+id/txtName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#1D1D1D"
            android:textSize="24sp" />

        <TextView
            android:id="@+id/txtComment"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#B4B4B4"
            android:textSize="14sp" />

    </LinearLayout>

</LinearLayout>

项目地址 https://github.com/webabcd/AndroidDemo
作者 webabcd