Android 常用数据适配器ArrayAdapter

时间:2023-03-08 22:42:26
Android 常用数据适配器ArrayAdapter

接着上篇文章《Android 采用Layout Inflater创建一个View对象》,本文采用常用数据适配器ArrayAdapter

新建项目后,在layout文件夹下新建list_item.xml文件,接着编辑布局,代码如下:

<?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="wrap_content"
android:orientation="horizontal" > <ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" /> <TextView
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content" /> </LinearLayout>

接着在MainActivity中添加代码:

package com.wuyudong.arrayadapter;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListView; public class MainActivity extends Activity { private static String[] names = { "功能1", "功能2", "功能3", "功能4", "功能5" }; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); ListView lv = (ListView) findViewById(R.id.lv);
lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item,
R.id.tv, names)); }
}

运行一下:

Android 常用数据适配器ArrayAdapter

ArrayAdapter的构造函数较多,其中的参数的含义可以参见源代码

   /**
* Constructor
*
* @param context The current context.
* @param resource The resource ID for a layout file containing a TextView to use when
* instantiating views.
*/
public ArrayAdapter(Context context, int resource) {
init(context, resource, 0, new ArrayList<T>());
} /**
* Constructor
*
* @param context The current context.
* @param resource The resource ID for a layout file containing a layout to use when
* instantiating views.
* @param textViewResourceId The id of the TextView within the layout resource to be populated
*/
public ArrayAdapter(Context context, int resource, int textViewResourceId) {
init(context, resource, textViewResourceId, new ArrayList<T>());
} /**
* Constructor
*
* @param context The current context.
* @param resource The resource ID for a layout file containing a TextView to use when
* instantiating views.
* @param objects The objects to represent in the ListView.
*/
public ArrayAdapter(Context context, int resource, T[] objects) {
init(context, resource, 0, Arrays.asList(objects));
} /**
* Constructor
*
* @param context The current context.
* @param resource The resource ID for a layout file containing a layout to use when
* instantiating views.
* @param textViewResourceId The id of the TextView within the layout resource to be populated
* @param objects The objects to represent in the ListView.
*/
public ArrayAdapter(Context context, int resource, int textViewResourceId, T[] objects) {
init(context, resource, textViewResourceId, Arrays.asList(objects));
} /**
* Constructor
*
* @param context The current context.
* @param resource The resource ID for a layout file containing a TextView to use when
* instantiating views.
* @param objects The objects to represent in the ListView.
*/
public ArrayAdapter(Context context, int resource, List<T> objects) {
init(context, resource, 0, objects);
} /**
* Constructor
*
* @param context The current context.
* @param resource The resource ID for a layout file containing a layout to use when
* instantiating views.
* @param textViewResourceId The id of the TextView within the layout resource to be populated
* @param objects The objects to represent in the ListView.
*/
public ArrayAdapter(Context context, int resource, int textViewResourceId, List<T> objects) {
init(context, resource, textViewResourceId, objects);
}