在Activity中响应ListView内部按钮的点击事件的两种方法

转载：http://www.cnblogs.com/ivan-xu/p/4124967.html

最近交流群里面有人问到一个问题：如何在Activity中响应ListView内部按钮的点击事件，不要在Adapter中响应？

对于这个问题，我最初给他的解答是，在Adapter中定义一个回调接口，在Activity中实现该接口，从而实现对点击事件的响应。

下班后思考了一下，觉得有两种方式都能比较好的实现：使用接口回调和使用抽象类回调。

正好可以复习一下接口和抽象类的区别，于是写了两个Demo：

1.使用接口回调：

Adapter类

 1 package com.ivan.adapter;
 2 
 3 import java.util.List;
 4 
 5 import android.content.Context;
 6 import android.util.Log;
 7 import android.view.LayoutInflater;
 8 import android.view.View;
 9 import android.view.View.OnClickListener;
10 import android.view.ViewGroup;
11 import android.widget.BaseAdapter;
12 import android.widget.Button;
13 import android.widget.TextView;
14 
15 import com.ivan.listvieweventcallback.R;
16 
17 public class ContentAdapter extends BaseAdapter implements OnClickListener {
18 
19     private static final String TAG = "ContentAdapter";
20     private List<String> mContentList;
21     private LayoutInflater mInflater;
22     private Callback mCallback;
23 
24     /**
25      * 自定义接口，用于回调按钮点击事件到Activity
26      * @author Ivan Xu
27      * 2014-11-26
28      */
29     public interface Callback {
30         public void click(View v);
31     }
32 
33     public ContentAdapter(Context context, List<String> contentList,
34             Callback callback) {
35         mContentList = contentList;
36         mInflater = LayoutInflater.from(context);
37         mCallback = callback;
38     }
39 
40     @Override
41     public int getCount() {
42         Log.i(TAG, "getCount");
43         return mContentList.size();
44     }
45 
46     @Override
47     public Object getItem(int position) {
48         Log.i(TAG, "getItem");
49         return mContentList.get(position);
50     }
51 
52     @Override
53     public long getItemId(int position) {
54         Log.i(TAG, "getItemId");
55         return position;
56     }
57 
58     @Override
59     public View getView(int position, View convertView, ViewGroup parent) {
60         Log.i(TAG, "getView");
61         ViewHolder holder = null;
62         if (convertView == null) {
63             convertView = mInflater.inflate(R.layout.list_item, null);
64             holder = new ViewHolder();
65             holder.textView = (TextView) convertView
66                     .findViewById(R.id.textView1);
67             holder.button = (Button) convertView.findViewById(R.id.button1);
68             convertView.setTag(holder);
69         } else {
70             holder = (ViewHolder) convertView.getTag();
71         }
72         holder.textView.setText(mContentList.get(position));
73 
74         
75         holder.button.setOnClickListener(this);
76         holder.button.setTag(position);
77         return convertView;
78     }
79 
80     public class ViewHolder {
81         public TextView textView;
82         public Button button;
83     }
84 
85     //响应按钮点击事件,调用子定义接口，并传入View
86     @Override
87     public void onClick(View v) {
88         mCallback.click(v);
89     }
90 }

Activity类：

 1 package com.ivan.listvieweventdemo;
 2 
 3 import java.util.ArrayList;
 4 import java.util.List;
 5 
 6 import android.app.Activity;
 7 import android.os.Bundle;
 8 import android.view.Menu;
 9 import android.view.View;
10 import android.widget.AdapterView;
11 import android.widget.AdapterView.OnItemClickListener;
12 import android.widget.ListView;
13 import android.widget.Toast;
14 
15 import com.ivan.adapter.ContentAdapter;
16 import com.ivan.adapter.ContentAdapter.Callback;
17 import com.ivan.listvieweventcallback.R;
18 //MainActivity需要实现自定义接口
19 public class MainActivity extends Activity implements OnItemClickListener,
20         Callback {
21 
22     // 模拟listview中加载的数据
23     private static final String[] CONTENTS = { "北京", "上海", "广州", "深圳", "苏州",
24             "南京", "武汉", "长沙", "杭州" };
25     private List<String> contentList;
26     private ListView mListView;
27 
28     @Override
29     protected void onCreate(Bundle savedInstanceState) {
30         super.onCreate(savedInstanceState);
31         setContentView(R.layout.activity_main);
32 
33         init();
34     }
35 
36     private void init() {
37         mListView = (ListView) findViewById(R.id.listview);
38         contentList = new ArrayList<String>();
39         for (int i = 0; i < CONTENTS.length; i++) {
40             contentList.add(CONTENTS[i]);
41         }
42         //
43         mListView.setAdapter(new ContentAdapter(this, contentList, this));
44         mListView.setOnItemClickListener(this);
45     }
46 
47     @Override
48     public boolean onCreateOptionsMenu(Menu menu) {
49         getMenuInflater().inflate(R.menu.main, menu);
50         return true;
51     }
52 
53     /**
54      * 响应ListView中item的点击事件
55      */
56     @Override
57     public void onItemClick(AdapterView<?> arg0, View v, int position, long id) {
58         Toast.makeText(this, "listview的item被点击了！，点击的位置是-->" + position,
59                 Toast.LENGTH_SHORT).show();
60     }
61 
62     /**
63      * 接口方法，响应ListView按钮点击事件
64      */
65     @Override
66     public void click(View v) {
67         Toast.makeText(
68                 MainActivity.this,
69                 "listview的内部的按钮被点击了！，位置是-->" + (Integer) v.getTag() + ",内容是-->"
70                         + contentList.get((Integer) v.getTag()),
71                 Toast.LENGTH_SHORT).show();
72     }
73 }

2.使用抽象类回调

Adapter类：

 1 package com.ivan.adapter;
 2 
 3 import java.util.List;
 4 
 5 import android.content.Context;
 6 import android.util.Log;
 7 import android.view.LayoutInflater;
 8 import android.view.View;
 9 import android.view.View.OnClickListener;
10 import android.view.ViewGroup;
11 import android.widget.BaseAdapter;
12 import android.widget.Button;
13 import android.widget.TextView;
14 
15 import com.ivan.listvieweventabstract.R;
16 
17 public class ContentAdapter extends BaseAdapter {
18 
19     private static final String TAG = "ContentAdapter";
20     private List<String> mContentList;
21     private LayoutInflater mInflater;
22     private MyClickListener mListener;
23 
24     public ContentAdapter(Context context, List<String> contentList,
25             MyClickListener listener) {
26         mContentList = contentList;
27         mInflater = LayoutInflater.from(context);
28         mListener = listener;
29     }
30 
31     @Override
32     public int getCount() {
33         Log.i(TAG, "getCount");
34         return mContentList.size();
35     }
36 
37     @Override
38     public Object getItem(int position) {
39         Log.i(TAG, "getItem");
40         return mContentList.get(position);
41     }
42 
43     @Override
44     public long getItemId(int position) {
45         Log.i(TAG, "getItemId");
46         return position;
47     }
48 
49     @Override
50     public View getView(int position, View convertView, ViewGroup parent) {
51         Log.i(TAG, "getView");
52         ViewHolder holder = null;
53         if (convertView == null) {
54             convertView = mInflater.inflate(R.layout.list_item, null);
55             holder = new ViewHolder();
56             holder.textView = (TextView) convertView
57                     .findViewById(R.id.textView1);
58             holder.button = (Button) convertView.findViewById(R.id.button1);
59             convertView.setTag(holder);
60         } else {
61             holder = (ViewHolder) convertView.getTag();
62         }
63         holder.textView.setText(mContentList.get(position));
64         holder.button.setOnClickListener(mListener);
65         holder.button.setTag(position);
66         return convertView;
67     }
68 
69     public class ViewHolder {
70         public TextView textView;
71         public Button button;
72     }
73 
74     /**
75      * 用于回调的抽象类
76      * @author Ivan Xu
77      * 2014-11-26
78      */
79     public static abstract class MyClickListener implements OnClickListener {
80         /**
81          * 基类的onClick方法
82          */
83         @Override
84         public void onClick(View v) {
85             myOnClick((Integer) v.getTag(), v);
86         }
87         public abstract void myOnClick(int position, View v);
88     }
89 }

Activity类：

 1 package com.ivan.listvieweventdemo;
 2 
 3 import java.util.ArrayList;
 4 import java.util.List;
 5 
 6 import android.app.Activity;
 7 import android.os.Bundle;
 8 import android.view.Menu;
 9 import android.view.View;
10 import android.widget.AdapterView;
11 import android.widget.AdapterView.OnItemClickListener;
12 import android.widget.ListView;
13 import android.widget.Toast;
14 
15 import com.ivan.adapter.ContentAdapter;
16 import com.ivan.adapter.ContentAdapter.MyClickListener;
17 import com.ivan.listvieweventabstract.R;
18 
19 public class MainActivity extends Activity implements OnItemClickListener {
20 
21     // 模拟listview中加载的数据
22     private static final String[] CONTENTS = { "北京", "上海", "广州", "深圳", "苏州",
23             "南京", "武汉", "长沙", "杭州" };
24     private List<String> contentList;
25     private ListView mListView;
26 
27     @Override
28     protected void onCreate(Bundle savedInstanceState) {
29         super.onCreate(savedInstanceState);
30         setContentView(R.layout.activity_main);
31 
32         init();
33     }
34 
35     private void init() {
36         mListView = (ListView) findViewById(R.id.listview);
37         contentList = new ArrayList<String>();
38         for (int i = 0; i < CONTENTS.length; i++) {
39             contentList.add(CONTENTS[i]);
40         }
41         //实例化ContentAdapter类，并传入实现类
42         mListView.setAdapter(new ContentAdapter(this, contentList, mListener));
43         
44         mListView.setOnItemClickListener(this);
45     }
46 
47     @Override
48     public boolean onCreateOptionsMenu(Menu menu) {
49         getMenuInflater().inflate(R.menu.main, menu);
50         return true;
51     }
52 
53     //响应item点击事件
54     @Override
55     public void onItemClick(AdapterView<?> arg0, View v, int position, long id) {
56         Toast.makeText(this, "listview的item被点击了！，点击的位置是-->" + position,
57                 Toast.LENGTH_SHORT).show();
58     }
59 
60     /**
61      * 实现类，响应按钮点击事件
62      */
63     private MyClickListener mListener = new MyClickListener() {
64         @Override
65         public void myOnClick(int position, View v) {
66             Toast.makeText(
67                     MainActivity.this,
68                     "listview的内部的按钮被点击了！，位置是-->" + position + ",内容是-->"
69                             + contentList.get(position), Toast.LENGTH_SHORT)
70                     .show();
71         }
72     };
73 }

以下是布局文件

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:paddingBottom="@dimen/activity_vertical_margin"
 6     android:paddingLeft="@dimen/activity_horizontal_margin"
 7     android:paddingRight="@dimen/activity_horizontal_margin"
 8     android:paddingTop="@dimen/activity_vertical_margin"
 9     tools:context=".MainActivity" >
10 
11     <ListView
12         android:id="@+id/listview"
13         android:layout_width="match_parent"
14         android:layout_height="match_parent" >
15     </ListView>
16 
17 </RelativeLayout>

<?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:descendantFocusability="blocksDescendants"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="content"
        android:textColor="#ff0000"
        android:textSize="20sp" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:focusable="false"
        android:text="Button"
        android:textColor="#ff0000"
        android:textSize="20sp" />

</LinearLayout>

两种方式的区别在于，抽象类在Activity中实现的时候，只能定义一个成员变量来实现，不能由Activity直接实现，因为Java不支持多继承。而接口既可以由Activity直接实现，也可以由其成员变量来实现。