Adapter（适配器的讲解）
适配器就我自己来看，我觉得这是一个非常重要的知识点，Adapter是用来帮助填出数据的中间桥梁，简单点说吧：将各种数据以合适的形式显示在View中给用户看。Adapter有很多的接口、抽象类、子类可以使用，这里就我们常用的几个进行讲解
BaseAdapter，ArrayAdapter，SimpleAdapter，为了配合讲解这几个适配器，这里提前使用一下ListView来展示一下适配器的使用，后面会对ListView进行进一步总结。
一、ArrayAdapter（数组适配器），这个适配器使用有一定的局限性，只能显示一行文本数据
（1）基本使用实例
布局文件：
<??><LinearLayout ="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <ListView android:id="@+id/ll1" android:layout_width="match_parent" android:layout_height="wrap_content"> </ListView></LinearLayout>
Java文件
package com.example.test3;import android.app.Activity;import android.os.Bundle;import android.widget.ArrayAdapter;import android.widget.ListView;public class MainActivity extends Activity{// 定义要显示的数据 private String[] datas = {"张三","李四","王五","麻子","小强"}; private ArrayAdapter<String> adapter; private ListView listView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); listView = (ListView) findViewById(R.id.ll1);// 初始化适配器 adapter = new ArrayAdapter<>(this,android.R.layout.simple_expandable_list_item_1,datas); listView.setAdapter(adapter); }}效果图：
images/loading.gif' 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" />
（2）实现上面还可以先在res\value下创建一个数组资源的
3、ArrayAdapter也支持泛型，那么集合肯定必须的，还可以如下所写
simple_list_item2:有两个文本框组成
simple_list_item_checked每项都是由一个已选中的列表项
simple_list_item_multiple_choice:都带有一个复选框
simple_list_item_single_choice：都带有一个单选框
二、SimpleAdapter（简单适配器）：这个适配器不要被名字迷惑，看是简单，但功能强大
（1）基本使用实例
<??><LinearLayout ="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <ListView android:id="@+id/ll1" android:layout_width="match_parent" android:layout_height="wrap_content"> </ListView></LinearLayout>
定义要实现的item的样式
<??><LinearLayout ="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal"> <ImageView android:id="@+id/image1" android:layout_width="100dp" android:layout_height="100dp" android:src='/images/loading.gif' data-original="@mipmap/ic_launcher" android:layout_margin="5dp"/> <LinearLayout android:id="@+id/ll2" android:layout_width="match_parent" android:layout_height="100dp" android:orientation="vertical" android:layout_marginTop="5dp" android:layout_marginLeft="10dp"> <TextView android:id="@+id/text1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="哈哈" android:textSize="30sp" android:layout_marginTop="10dp"/> <TextView android:id="@+id/text2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="哈哈哈哈哈" android:textSize="24dp" android:layout_marginTop="10dp"/> </LinearLayout></LinearLayout>
Java文件
package com.example.test3;import android.app.Activity;import android.os.Bundle;import android.widget.ListView;import android.widget.SimpleAdapter;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;public class MainActivity extends Activity{// 这三个经常是同时出现的 private List<Map<String,Object>> lists; private SimpleAdapter adapter; private ListView listView;// 定义数据 private String[] theme = {"张三","李四","王五"}; private String[] content ={"我是张三，你好","我是李四，你好","我是王五，你好"}; private int[] imageViews = {R.mipmap.ic_launcher,R.mipmap.ic_account,R.mipmap.ic_password}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); listView = (ListView) findViewById(R.id.ll1);// 准备数据源 lists = new ArrayList<>(); for(int i = 0;i < theme.length;i++){ Map<String,Object> map =new HashMap<>(); map.put("image",imageViews[i]); map.put("theme",theme[i]); map.put("content",content[i]); lists.add(map); } adapter = new SimpleAdapter(MainActivity.this,lists,R.layout.list_item ,new String[]{"image","theme","content"} ,new int[]{R.id.image1,R.id.text1,R.id.text2}); listView.setAdapter(adapter); }}效果图：
（2）simpleAdapter中五个参数的
第一个参数：上下文对象
第二个参数：数据源是含有Map的一个集合
第三个参数：每一个item的布局文件
第四个参数：new String[]{}数组，数组的里面的每一项要与第二个参数中的存入map集合的的key值一样，一一对应
第五个参数：new int[]{}数组，数组里面的第三个参数中的item里面的控件id。
三、BaseAdapter使用的非常多，现在使用BaseAdapter也同样的实现上面的效果。
（1）布局文件和每一个item的显示都和上面SimpleAdapter一样的主要是在Java里面的文件，在使用BaseAdapter我们继承它，并且实现里面抽象方法。
自定义adapter
package com.example.test3;import android.content.Context;import android.text.Layout;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.TextView;import java.util.ArrayList;import java.util.List;/** * Created by coder-tu on 2016/1/13. */public class MyAdapter extends BaseAdapter { private List<Message> Datas; private Context mContext; public MyAdapter(List<Message> datas, Context mContext) { Datas = datas; this.mContext = mContext; } /** * 返回item的个数 * @return */ @Override public int getCount() { return Datas.size(); } /** * 返回每一个item对象 * @param i * @return */ @Override public Object getItem(int i) { return Datas.get(i); } /** * 返回每一个item的id * @param i * @return */ @Override public long getItemId(int i) { return i; } /** * 暂时不做优化处理，后面会专门整理BaseAdapter的优化 * @param i * @param view * @param viewGroup * @return */ @Override public View getView(int i, View view, ViewGroup viewGroup) { view = LayoutInflater.from(mContext).inflate(R.layout.list_item,viewGroup,false); ImageView imageView = (ImageView) view.findViewById(R.id.image1); TextView textView1 = (TextView) view.findViewById(R.id.text1); TextView textView2 = (TextView) view.findViewById(R.id.text2); imageView.setImageResource(Datas.get(i).getImageId()); textView1.setText(Datas.get(i).getTheme()); textView2.setText(Datas.get(i).getContent());// 此处需要返回view 不能是view中某一个 return view; }}然后在Java文件中使用
package com.example.test3;import android.app.Activity;import android.os.Bundle;import android.widget.ListView;import java.util.ArrayList;import java.util.List;public class MainActivity extends Activity{// 这三个经常是同时出现的 private List<Message> lists; private MyAdapter adapter; private ListView listView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); listView = (ListView) findViewById(R.id.ll1); lists = new ArrayList<>(); lists.add(new Message(R.mipmap.ic_launcher,"张三","你好，我是张三")); lists.add(new Message(R.mipmap.ic_account,"李四","你好，我是李四")); lists.add(new Message(R.mipmap.ic_password,"王五","你好，我是王五")); adapter = new MyAdapter(lists,MainActivity.this); listView.setAdapter(adapter); }}效果图：
文艺式：这种写法非常好，即利用了listView的缓存机制，又避免了重复的findViewById
1、创建内部类 2、判断convertView是否为空 3通过setTag方法将viewHolder与convertView建立关系绑定
小结：对这三种适配器来说，BaseAdapter使用相对最广，因为局限性小，使用起来更加自由
原标题：android中Adapter适配器的讲解
关键词：Android
我知道了 