在Activity中响应ListView内部按钮的点击事件

来源：互联网发布：进口食品js号编辑：程序博客网时间：2024/04/29 13:23

转载自：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

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();        }    };}

以下是布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <ListView        android:id="@+id/listview"        android:layout_width="match_parent"        android:layout_height="match_parent" >    </ListView></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。

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