listview 内部按钮的点击事件

来源:互联网 发布:mac谷歌浏览器安装 编辑:程序博客网 时间:2024/03/29 20:57

一。ListView的Item被点击和其中的Button被点击同时生效

 Android开发中在ListView中经常有Button或ImageButton等需要被点击的控件,如果不加一些特殊的限制,有可能ListView的Item的点击事件或Button的点击事件,其中一个不能响应。我遇到的情况是ListView的Item不能响应点击事件。

        解决的办法,在ListView的Item的xml文件中添加如下属性:

                1)整个xml文件的根元素如LinearLayout中添加属性android:descendantFocusability="blocksDescendants"

                2)被点击的控件如ImageButton中添加属性android:focusable="false"和android:clickable="true"

        完美解决!


二。实现代码

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

复制代码
复制代码
 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Activity26      * @author Ivan Xu27      * 2014-11-2628      */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     @Override41     public int getCount() {42         Log.i(TAG, "getCount");43         return mContentList.size();44     }45 46     @Override47     public Object getItem(int position) {48         Log.i(TAG, "getItem");49         return mContentList.get(position);50     }51 52     @Override53     public long getItemId(int position) {54         Log.i(TAG, "getItemId");55         return position;56     }57 58     @Override59     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) convertView66                     .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View86     @Override87     public void onClick(View v) {88         mCallback.click(v);89     }90 }
复制代码
复制代码

Activity类:

复制代码
复制代码
 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     @Override29     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     @Override48     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     @Override57     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     @Override66     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 }
复制代码
复制代码

2.使用抽象类回调

Adapter类:

复制代码
复制代码
 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     @Override32     public int getCount() {33         Log.i(TAG, "getCount");34         return mContentList.size();35     }36 37     @Override38     public Object getItem(int position) {39         Log.i(TAG, "getItem");40         return mContentList.get(position);41     }42 43     @Override44     public long getItemId(int position) {45         Log.i(TAG, "getItemId");46         return position;47     }48 49     @Override50     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) convertView57                     .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 Xu77      * 2014-11-2678      */79     public static abstract class MyClickListener implements OnClickListener {80         /**81          * 基类的onClick方法82          */83         @Override84         public void onClick(View v) {85             myOnClick((Integer) v.getTag(), v);86         }87         public abstract void myOnClick(int position, View v);88     }89 }
复制代码
复制代码

Activity类:

复制代码
复制代码
 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     @Override28     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     @Override48     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     @Override55     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         @Override65         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 }
复制代码
复制代码

 

以下是布局文件

复制代码
复制代码
 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     <ListView12         android:id="@+id/listview"13         android:layout_width="match_parent"14         android:layout_height="match_parent" >15     </ListView>16 17 </RelativeLayout>
复制代码
复制代码
复制代码
复制代码
<?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>
复制代码
复制代码

 

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。


0 1
原创粉丝点击