Android开发中在Activity中响应ListView内部按钮的点击事件的两种方法

来源:网页教学基地 时间:2017-01-09 09:00:55  浏览次数:0

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脚本之家。

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