Android之ListView控件

Android之ListView控件 ListView类

ListView的主要属性

stackFromBottom，设置为true时，内容将从底部开始显示 cacheColorHint，设置为#00000000透明时，可以避免拖动时背景显示黑色的问题 divider，设置分割线，#00000000或@null分割线被隐藏 fadingEdge，设置为none，去除上边和下边的阴影 scrollbars，设置为none，隐藏滚动条 ListView介绍

ListView组件可以实现循环显示自定义组件的功能。

首先在显示ListView的XML文件里声明一个ListView：

在主函数中调用ListView

public class MainActivity extends AppCompatActivity {
	//准备数据源
    private String[] data = { "Apple", "Banana", "Orange", "Watermelon", "Pear", "Grape",
    "Pineapple", "Strawberry", "Cherry", "ManGo", "Apple", "Banana", "Orange", "Watermelon",
     "Pear", "Grape", "Pineapple", "Strawberry", "Cherry", "Mango",};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //将数据源添加到适配器
        ArrayAdapter adapter = new ArrayAdapter(
                MainActivity.this, android.R.layout.simple_list_item_1,data);
        ListView listView = (ListView) findViewById(R.id.list_view);
        //将适配器中数据添加到ListView中
        listView.setAdapter(adapter);
    }
}

自定义ListView界面

自定义一个布局

定义好布局后，定义一个实体类，作为ListView适配器的适配类型

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;
    }
}

创建一个自定义适配器，继承ArrayAdapter

public class FruitAdapter extends ArrayAdapter {
    private int resourceId;
    public FruitAdapter(Context context, int textViewResourceId, List 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;
    }
}

getView()这个方法在每个子项被滚动到屏幕内部都会被调用。首先通过getItem()方法得到当前项的Fruit实例，然后使用LayoutInflater为这个子项加载传入的布局。

最后修改主函数

public class MainActivity extends AppCompatActivity {
    private List fruitList = new ArrayList();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initFruits(); // 初始化水果数据
        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.drawable.apple_pic);
            fruitList.add(apple);
            Fruit banana = new Fruit("Banana", R.drawable.banana_pic);
            fruitList.add(banana);
            Fruit orange = new Fruit("Orange", R.drawable.orange_pic);
            fruitList.add(orange);
            Fruit watermelon = new Fruit("Watermelon", R.drawable.watermelon_pic);
            fruitList.add(watermelon);
            Fruit pear = new Fruit("Pear", R.drawable.pear_pic);
            fruitList.add(pear);
            Fruit grape = new Fruit("Grape", R.drawable.grape_pic);
            fruitList.add(grape);
            Fruit pineapple = new Fruit("Pineapple", R.drawable.pineapple_pic);
            fruitList.add(pineapple);
            Fruit strawberry = new Fruit("Strawberry", R.drawable.strawberry_pic);
            fruitList.add(strawberry);
            Fruit cherry = new Fruit("Cherry", R.drawable.cherry_pic);
            fruitList.add(cherry);
            Fruit mango = new Fruit("Mango", R.drawable.mango_pic);
            fruitList.add(mango);
        }
    }
}

ListView 点击事件

在主函数中修改代码：

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView parent, View view,
                                    int position, long id) {
                Fruit fruit = fruitList.get(position);
                Toast.makeText(MainActivity.this, fruit.getName(), Toast.LENGTH_SHORT).show();
            }
        });

使用setOnItemClickListener()方法为ListView注册了一个监听器，当用户点击了ListView中任何一个子项，就会回调onItemClick()方法。该方法中可以通过position参数判断出用户点击的是哪一个子项。
设置表头表尾与分割线

ListView可以自己设置表头，表尾以及分割线。 footerDividersEnabled：是否在footerView(表尾)前绘制一个分隔条,默认为true headerDividersEnabled:是否在headerView(表头)前绘制一个分隔条,默认为true divider:设置分隔条,可以用颜色分割,也可以用drawable资源分割 dividerHeight:设置分隔条的高度

调用如下方法可对ListView表头或者表尾的属性进行设置：

addHeaderView(View v)：添加headView(表头),括号中的参数是一个View对象 addFooterView(View v)：添加footerView(表尾)，括号中的参数是一个View对象 addHeaderView(headView, null, false)：和前面的区别：设置Header是否可以被选中 addFooterView(View,view,false)：同上 ListView常用属性 android:divider="#f9b68b" ：分割线颜色或样式 android:scrollbars=“none”：不显示滚动条 android:fadingEdge=“none” ：去掉上边和下边黑色的阴影 android:divider="@drawable/@null" ：不想显示分割线 android:scrollbars=“none” setVerticalScrollBarEnabled(true);：隐藏listView的滚动条 android:fadeScrollbars=“true” ：设置为true就可以实现滚动条的自动隐藏和显示 android:fastScrollEnabled = “true” ：加快滑动速度 android:listSelector="@color/pink" listView item ：选中时的颜色
作者：builder2991