ListView_ArrayAdapter学习笔记

最新推荐文章于 2021-02-24 08:09:25 发布

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本文详细介绍了Android中ListView的基本用法及自定义实现过程。包括简单的ListView设置步骤，如何使用ArrayAdapter显示列表，以及如何通过创建自定义适配器、布局来展示更复杂的列表项。

学习了该书籍的ListView的用法总结出学习笔记还望指正

ListView的简单用法

1，在布局文件中添加listView文件 id为list_view

2，声明全局变量 ArrayAdapter<String>、ListView

3，添加数组 data

4，创建适配器

上下文 this

listView子项布局的id android.R.layout.simple_list_item_1

数据 data

5， Listview找到ID

6， Lisiview找到适配器

代码：

activity_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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.air1997.mylistviewtest1.MainActivity">

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/list_view"
        ></ListView>
</RelativeLayout>

MainActivity.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class MainActivity extends AppCompatActivity {
    private ArrayAdapter<String> arrayAdapter;
    private ListView listView;
    private String[] data={"apple","banana","orange"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        arrayAdapter=new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,data);
        listView=(ListView)findViewById(R.id.list_view);
        listView.setAdapter(arrayAdapter);
    }
}

输出效果如下：

定制ListView 的界面

1，定制适配器的适配类型即新建一个类如Fruit类

public class Fruit {
    private String name;

    public int getImageId() {
        return imageId;
    }

    public void setImageId(int imageId) {
        this.imageId = imageId;
    }

    public String getName() {
        return name;
    }

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

    private int imageId;
}

2，创建一个定制的布局如fruit_item.xml并添加Image、TextView 且有各自的id

3，定制一个适配器继承ArrayAdapter适配器例如FruitAdapter

4，声明全局变量resourId

5，在MainActivity.java中使用适配器

代码如下：

activity.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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.air1997.mylistviewtest1.MainActivity">

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/list_view"
        ></ListView>
</RelativeLayout>

MainActivity.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private ArrayAdapter<String> arrayAdapter;
    private ListView listView;
    private String[] data={"apple","banana","orange"};
    private List<Fruit> fruitList=new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initFruits();
        FruitAdapter adapter=new FruitAdapter(MainActivity.this,R.layout.fruit_item,fruitList);
        ListView listView=(ListView)findViewById(R.id.list_view);
        listView.setAdapter(adapter);
    }
    private void initFruits(){
        for (int i=0;i<2;i++){
            Fruit apple=new Fruit("Apple",R.mipmap.ic_launcher);
            fruitList.add(apple);
            Fruit banana=new Fruit("Banana",R.mipmap.ic_launcher);
            fruitList.add(banana);
            Fruit orange=new Fruit("Orange",R.mipmap.ic_launcher);
            fruitList.add(orange);

        }
    }
}

fruit_item.xml

<?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">
<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/fruit_image"
    />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/fruit_name"

        />
</LinearLayout>

FruitAdapter.java

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

import java.util.List;

/**
 * Created by AIR1997 on 2017/3/9.
 */
public class FruitAdapter extends ArrayAdapter<Fruit> {
    private int resourceId;
    public FruitAdapter(Context context, int textViewResourceId, List<Fruit> objects){
        super(context,textViewResourceId,objects);
        resourceId=textViewResourceId;
    }
    @Override
    public View getView(int position , View convertView, ViewGroup parent){
        Fruit fruit=getItem(position);
        View view = LayoutInflater.from(getContext()).inflate(resourceId,parent,false);
        ImageView fruitImage=(ImageView)view.findViewById(R.id.fruit_image);
        TextView fruitName=(TextView)view.findViewById(R.id.fruit_name);
        fruitImage.setImageResource(fruit.getImageId());
        fruitName.setText(fruit.getName());
        return view;
    }
}

Fruit.java

public class Fruit {
    private String name;
    private int imageId;
    public Fruit(String name,int imageId){
        this.name=name;
        this.imageId=imageId;
    }
    public String getName(){
        return name;
    }
    public int getImageId(){
        return imageId;
    }

}

效果如下：