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。
原文链接：http://blog.csdn.net/u011895534/article/details/50439547
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持查字典教程网。