自定义ListView

一.定义内容类Fruit

 

public class Fruit {

    private String name;

    private int imageId;

 

    public Fruit(String name,int imageId) {

        this.imageId = imageId;

        this.name = name;

    }

 

    public int getImageId() {

        return imageId;

    }

 

    public String getName() {

        return name;

    }

}

　　

 

二.定义item布局,fruit_item.xml

<?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"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="horizontal">

 

 

    <ImageView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/fruit_image"

        />

 

    <TextView

        android:text="TextView"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/fruit_name"

        android:gravity="center"

        android:layout_marginLeft="15dp"

        android:layout_gravity="center"

        />

</LinearLayout>

　　

 

三.定义Adapter,FruitAdpater

public class FruitAdapter extends ArrayAdapter<Fruit> {

 

    private int resourceId;

 

    public FruitAdapter(Context context, int resource, List<Fruit> objects) {

        super(context, resource, objects);

        this.resourceId = resource;

    }

 

    @NonNull

    @Override

    public View getView(int position, View convertView, ViewGroup parent) {

        Fruit fruit = getItem(position);

        View view = LayoutInflater.from(getContext()).inflate(resourceId, null);

        ImageView imageView = (ImageView)view.findViewById(R.id.fruit_image);

        TextView textView = (TextView)view.findViewById(R.id.fruit_name);

        imageView.setImageResource(fruit.getImageId());

        textView.setText(fruit.getName());

        return view;

    }

}

　　

 

 

FruitAdapter 重写了父类的一组构造函数，用于将上下文、ListView 子项布局的id和数据都传递进来。另外又重写了getView()方法，这个方法在每个子项被滚动到屏幕内的时候会被调用。在getView 方法中，首先通过getItem()方法得到当前项的Fruit 实例，然后使用LayoutInflater 来为这个子项加载我们传入的布局， 接着调用View 的findViewById()方法分别获取到ImageView 和TextView 的实例，并分别调用它们的setImageResource()和setText()方法来设置显示的图片和文字，最后将布局返回，这样我们自定义的适配器就完成了。

 

 

 

四.Activity调用

 

private List<Fruit> fruitList = new ArrayList<Fruit>();

 

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

 

        initFruit();

        FruitAdapter fruitAdapter = new FruitAdapter(this, R.layout.fruit_item, fruitList);

        ListView listView = (ListView)findViewById(R.id.listview);

        listView.setAdapter(fruitAdapter);

    }

 

    private void initFruit(){

        Fruit fruit;

        fruit= new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

        fruit = new Fruit("苹果", R.mipmap.ic_launcher);

        fruitList.add(fruit);

 

    }

　　

  

 

五.最终成图