在Activity中响应ListView内部按钮的点击事件的两种方法

http://blog.csdn.net/u011895534/article/details/50439547

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

package com.ivan.adapter;

import java.util.List;

import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;

import com.ivan.listvieweventcallback.R;

public class ContentAdapter extends BaseAdapter implements OnClickListener {

private static final String TAG = "ContentAdapter";
private List<String> mContentList;
private LayoutInflater mInflater;
private Callback mCallback;

/**
* 自定义接口，用于回调按钮点击事件到Activity
* @author Ivan Xu
* 2014-11-26
*/
public interface Callback {
public void click(View v);
}

public ContentAdapter(Context context, List<String> contentList,
Callback callback) {
mContentList = contentList;
mInflater = LayoutInflater.from(context);
mCallback = callback;
}

@Override
public int getCount() {
Log.i(TAG, "getCount");
return mContentList.size();
}

@Override
public Object getItem(int position) {
Log.i(TAG, "getItem");
return mContentList.get(position);
}

@Override
public long getItemId(int position) {
Log.i(TAG, "getItemId");
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
Log.i(TAG, "getView");
ViewHolder holder = null;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
holder.textView = (TextView) convertView
.findViewById(R.id.textView1);
holder.button = (Button) convertView.findViewById(R.id.button1);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.textView.setText(mContentList.get(position));

holder.button.setOnClickListener(this);
holder.button.setTag(position);
return convertView;
}

public class ViewHolder {
public TextView textView;
public Button button;
}

//响应按钮点击事件,调用子定义接口，并传入View
@Override
public void onClick(View v) {
mCallback.click(v);
}
} Activity类：

package com.ivan.listvieweventdemo;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.Toast;

import com.ivan.adapter.ContentAdapter;
import com.ivan.adapter.ContentAdapter.Callback;
import com.ivan.listvieweventcallback.R;
//MainActivity需要实现自定义接口
public class MainActivity extends Activity implements OnItemClickListener,
Callback {

// 模拟listview中加载的数据
private static final String[] CONTENTS = { "北京", "上海", "广州", "深圳", "苏州",
"南京", "武汉", "长沙", "杭州" };
private List<String> contentList;
private ListView mListView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

init();
}

private void init() {
mListView = (ListView) findViewById(R.id.listview);
contentList = new ArrayList<String>();
for (int i = 0; i < CONTENTS.length; i++) {
contentList.add(CONTENTS[i]);
}
//
mListView.setAdapter(new ContentAdapter(this, contentList, this));
mListView.setOnItemClickListener(this);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

/**
* 响应ListView中item的点击事件
*/
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position, long id) {
Toast.makeText(this, "listview的item被点击了！，点击的位置是-->" + position,
Toast.LENGTH_SHORT).show();
}

/**
* 接口方法，响应ListView按钮点击事件
*/
@Override
public void click(View v) {
Toast.makeText(
MainActivity.this,
"listview的内部的按钮被点击了！，位置是-->" + (Integer) v.getTag() + ",内容是-->"
+ contentList.get((Integer) v.getTag()),
Toast.LENGTH_SHORT).show();
}
}

2.使用抽象类回调

Adapter类：

package com.ivan.adapter;

import java.util.List;

import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;

import com.ivan.listvieweventabstract.R;

public class ContentAdapter extends BaseAdapter {

private static final String TAG = "ContentAdapter";
private List<String> mContentList;
private LayoutInflater mInflater;
private MyClickListener mListener;

public ContentAdapter(Context context, List<String> contentList,
MyClickListener listener) {
mContentList = contentList;
mInflater = LayoutInflater.from(context);
mListener = listener;
}

@Override
public int getCount() {
Log.i(TAG, "getCount");
return mContentList.size();
}

@Override
public Object getItem(int position) {
Log.i(TAG, "getItem");
return mContentList.get(position);
}

@Override
public long getItemId(int position) {
Log.i(TAG, "getItemId");
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
Log.i(TAG, "getView");
ViewHolder holder = null;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
holder.textView = (TextView) convertView
.findViewById(R.id.textView1);
holder.button = (Button) convertView.findViewById(R.id.button1);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.textView.setText(mContentList.get(position));
holder.button.setOnClickListener(mListener);
holder.button.setTag(position);
return convertView;
}

public class ViewHolder {
public TextView textView;
public Button button;
}

/**
* 用于回调的抽象类
* @author Ivan Xu
* 2014-11-26
*/
public static abstract class MyClickListener implements OnClickListener {
/**
* 基类的onClick方法
*/
@Override
public void onClick(View v) {
myOnClick((Integer) v.getTag(), v);
}
public abstract void myOnClick(int position, View v);
}

Activity类：

package com.ivan.listvieweventdemo;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.Toast;

import com.ivan.adapter.ContentAdapter;
import com.ivan.adapter.ContentAdapter.MyClickListener;
import com.ivan.listvieweventabstract.R;

public class MainActivity extends Activity implements OnItemClickListener {

// 模拟listview中加载的数据
private static final String[] CONTENTS = { "北京", "上海", "广州", "深圳", "苏州",
"南京", "武汉", "长沙", "杭州" };
private List<String> contentList;
private ListView mListView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

init();
}

private void init() {
mListView = (ListView) findViewById(R.id.listview);
contentList = new ArrayList<String>();
for (int i = 0; i < CONTENTS.length; i++) {
contentList.add(CONTENTS[i]);
}
//实例化ContentAdapter类，并传入实现类
mListView.setAdapter(new ContentAdapter(this, contentList, mListener));

mListView.setOnItemClickListener(this);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

//响应item点击事件
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position, long id) {
Toast.makeText(this, "listview的item被点击了！，点击的位置是-->" + position,
Toast.LENGTH_SHORT).show();
}

/**
* 实现类，响应按钮点击事件
*/
private MyClickListener mListener = new MyClickListener() {
@Override
public void myOnClick(int position, View v) {
Toast.makeText(
MainActivity.this,
"listview的内部的按钮被点击了！，位置是-->" + position + ",内容是-->"
+ contentList.get(position), Toast.LENGTH_SHORT)
.show();
}
};
}
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。