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Android UI 之 ListView

2024-07-15 06:04:22   217人阅读

一、在代码中创建（不适用XML布局文件）

1.创建一个项目：ListViewLearn

2.修改MainActivity，继承于ListActivity

3.创建一个String数组，用来保存ListView中的现实内容

package com.learn.listviewlearn.utility;public class Util {    public static final String[] COUNTRYS = { "中国", "美国", "俄罗斯", "英国", "法国" };}

4.修改onCreate方法，设置一个Adapter，数组中的内容在ListView中现实出来

    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        // setContentView(R.layout.activity_main);        this.setListAdapter(new ArrayAdapter<String>(this,                android.R.layout.simple_dropdown_item_1line, Util.COUNTRYS));    }

二、使用XML布局文件来定义ListView的样式

1.修改activity_main.xml文件，添加一个ListView，id必须为android:id="@android:id/list"

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <ListView        android:id="@android:id/list"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="#FFFFFF00" >    </ListView></LinearLayout>

2.修改OnCreate方法

    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        this.setListAdapter(new ArrayAdapter<String>(this,                android.R.layout.simple_dropdown_item_1line, Util.COUNTRYS));    }

三、使用XML布局文件来定义ListViewItem的样式

 1.首先创建一个list_view.xml的布局文件

<?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="horizontal" >    <ImageView        android:id="@+id/imageViewIcon"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:contentDescription="@string/icon" >    </ImageView>    <TextView        android:id="@+id/textViewContent"        android:layout_width="wrap_content"        android:layout_height="wrap_content" >    </TextView></LinearLayout>

2.然后创建一个Adapter继承于BaseAdapter，主要修改getCount()和getView()方法

package com.learn.listviewlearn.adapter;import com.learn.listviewlearn.R;import com.learn.listviewlearn.utility.Util;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;public class ListViewAdapter extends BaseAdapter {    private Context context;    public ListViewAdapter() {        // TODO Auto-generated constructor stub    }    @Override    public int getCount() {        return Util.COUNTRYS.length;    }    @Override    public Object getItem(int position) {        // TODO Auto-generated method stub        return null;    }    @Override    public long getItemId(int position) {        // TODO Auto-generated method stub        return 0;    }    @Override    public View getView(int position, View convertView, ViewGroup parent) {        if (convertView == null) {            convertView = LayoutInflater.from(context).inflate(R.layout.list_item, null);            ItemViewCache itemViewCache = new ItemViewCache();            itemViewCache.imageView = (ImageView)convertView.findViewById(R.id.imageViewIcon);            itemViewCache.textView = (TextView)convertView.findViewById(R.id.textViewContent);            convertView.setTag(itemViewCache);        }                ItemViewCache cache = (ItemViewCache) convertView.getTag();        cache.imageView.setImageResource(Util.images[position]);        cache.textView.setText(Util.COUNTRYS[position]);        return convertView;    }        private static class ItemViewCache{        public TextView textView;        public ImageView imageView;    }}

Util.java

package com.learn.listviewlearn.utility;import com.learn.listviewlearn.R;public class Util {    public static final String[] COUNTRYS = { "中国", "美国", "俄罗斯", "英国", "法国" };    public static final int[] images = { R.drawable.ic_launcher,            R.drawable.ic_launcher, R.drawable.ic_launcher,            R.drawable.ic_launcher, R.drawable.ic_launcher };}

四、为ListView添加Click事件。只需要在MainActivity中实现onListItemClick()方法

    @Override    protected void onListItemClick(ListView l, View v, int position, long id) {        Toast.makeText(this, "你选择了" + Util.COUNTRYS[position], Toast.LENGTH_SHORT)                .show();    }

源码：HelloListView.zip


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