八：基于xmpp的smack去获取好友列表并用ExpandableListView显示

r囧r小猫 2022-08-10 15:52 69阅读 0赞

**本篇来获取好友列表。为了像QQ一样，点击展开好友列表，所以用了ExpandableListView。**

**1、先来看一下效果，**

![Center][]

**2、先写布局文件，activity\_linkman.xml里面拖了一个ExpandableListView**

<?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/catalogopen" >
    
        <TextView
            android:id="@+id/tv_username"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:layout_marginLeft="20sp"
            android:textSize="20sp" />
    
        <TextView
            android:id="@+id/tv_presence"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBaseline="@+id/tv_username"
            android:layout_alignBottom="@+id/tv_username"
            android:layout_marginLeft="22dp"
            android:layout_toRightOf="@+id/tv_username" />
    
        <TextView
            android:id="@+id/tv_friends"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/tv_username"
            android:layout_below="@+id/tv_presence"
            android:paddingTop="10sp"
            android:paddingBottom="5sp"
            android:text="@string/tv_friends"
            android:textSize="20sp" />
    
        <ExpandableListView
            android:id="@+id/elv_linkman"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_below="@+id/tv_friends" >
    
        </ExpandableListView>
    
    </RelativeLayout>

**3、strings.xml里的代码：**

<string name="tv_friends">好友</string>
        <string name="imageDescription">group indicator</string>
        <string name="headxiang">头像</string>
        <string name="tv_friendName">廖伍星</string>
        <string name="tv_sign">sorry，我忘了我想说什么了。</string>

**4、LinkmanActivity.java类，先获取组和好友，获取组和好友还是看smack文档，再把它们放到ExpandableListView中，这个组件和listView差不多，同样是拖一个ExpandableListView控件，一看就明白了。**

package org.hkby.lwx.activity;
    
    import java.util.ArrayList;
    import java.util.Collection;
    import java.util.List;
    
    import org.hkby.lwx.adapter.AllEntryExpandableAdapter;
    import org.hkby.lwx.common.XmppTool;
    import org.jivesoftware.smack.Roster;
    import org.jivesoftware.smack.RosterEntry;
    import org.jivesoftware.smack.RosterGroup;
    
    import android.app.Activity;
    import android.content.Intent;
    import android.content.SharedPreferences;
    import android.os.Bundle;
    import android.view.View;
    import android.view.Window;
    import android.widget.ExpandableListView;
    import android.widget.ExpandableListView.OnChildClickListener;
    import android.widget.TextView;
    /**
     * linkman
     * @author liaowuxing
     *
     */
    public class LinkmanActivity extends Activity {
    	/**
    	 * called when this activity is first create
    	 */
    	private ExpandableListView elv_linkman;
    	private List<String> groutList;
    	private List<List<String>> childList;
    	private TextView tv_username;
    	private TextView tv_presence;
    	private String account;
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		requestWindowFeature(Window.FEATURE_NO_TITLE);
    		setContentView(R.layout.activity_linkman);
    		SharedPreferences sp = getSharedPreferences("username",
    				Activity.MODE_PRIVATE);
    		account = sp.getString("account", "");
    		initView();
    		initClick();
    		getData();
    	}
    
    	public void initView() {
    		elv_linkman = (ExpandableListView) this.findViewById(R.id.elv_linkman);
    		//not set group indicator
    		elv_linkman.setGroupIndicator(null);
    		//login account
    		tv_username = (TextView) this.findViewById(R.id.tv_username);
    		tv_username.setText(account);
    		//TODO Online status
    		tv_presence = (TextView) this.findViewById(R.id.tv_presence);
    		tv_presence.setText("在线");
    	}
    
    	public void initClick() {
    		elv_linkman.setOnChildClickListener(new OnChildClickListener() {
    			
    			@Override
    			public boolean onChildClick(ExpandableListView parent, View v,
    					int groupPosition, int childPosition, long id) {
    				Intent intent = new Intent(LinkmanActivity.this,
    						ChatActivity.class);
    				Bundle bundle = new Bundle();
    				String username = childList.get(groupPosition).get(childPosition);
    				bundle.putString("name", username);
    				intent.putExtra("b_name", bundle);
    				startActivity(intent);
    				return true;
    			}
    		});
    	}
    
    	/**
    	 * get all friends and set in the adapter
    	 */
    	public void getData() {
    		groutList = new ArrayList<String>();
    		childList = new ArrayList<List<String>>();
    		
    		Roster roster = XmppTool.getConnection().getRoster();
    		Collection<RosterGroup> entriesGroup = roster.getGroups();
    		for (RosterGroup group : entriesGroup) {
    			Collection<RosterEntry> entries = group.getEntries();
    			groutList.add(group.getName());
    			List<String> tempList = new ArrayList<String>();
    			for (RosterEntry entry : entries) {
    				tempList.add(entry.getName());
    			}
    			childList.add(tempList);
    		}
    		AllEntryExpandableAdapter adapter = new AllEntryExpandableAdapter(groutList, childList, LinkmanActivity.this);
    		elv_linkman.setAdapter(adapter);
    		adapter.notifyDataSetChanged();
    	}
    	
    	@Override
    	public void onBackPressed() {
    		super.onBackPressed();
    		if (XmppTool.getConnection() != null) {
    			XmppTool.closeConnection();
    		}
    	}
    }

**5、我们需要在建一个包，来专门放adapter，命名为：org.hkby.lwx.adapter，再建一个类AllEntryExpandableAdapter。**

package org.hkby.lwx.adapter;
    
    import java.util.List;
    
    import org.hkby.lwx.activity.R;
    
    import android.content.Context;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.BaseExpandableListAdapter;
    import android.widget.ImageView;
    import android.widget.TextView;
    /**
     * ExpandableListView's adapter
     * @author liaowuxing
     *
     */
    public class AllEntryExpandableAdapter extends BaseExpandableListAdapter {
    	private List<String> groupList;
    	private List<List<String>> childList;
    	private Context context;
    	private LayoutInflater mInflater;
    	public AllEntryExpandableAdapter(List<String> groupList,
    			List<List<String>> childList, Context context) {
    		super();
    		this.groupList = groupList;
    		this.childList = childList;
    		this.context = context;
    		mInflater = LayoutInflater.from(context);
    	}
    
    	@Override
    	public int getGroupCount() {
    		return groupList.size();
    	}
    
    	@Override
    	public int getChildrenCount(int groupPosition) {
    		return childList.get(groupPosition).size();
    	}
    
    	@Override
    	public Object getGroup(int groupPosition) {
    		return groupList.get(groupPosition);
    	}
    
    	@Override
    	public Object getChild(int groupPosition, int childPosition) {
    		return childList.get(groupPosition).get(childPosition);
    	}
    
    	@Override
    	public long getGroupId(int groupPosition) {
    		return groupPosition;
    	}
    
    	@Override
    	public long getChildId(int groupPosition, int childPosition) {
    		return childPosition;
    	}
    
    	@Override
    	public boolean hasStableIds() {
    		return true;
    	}
    
    	@Override
    	public View getGroupView(int groupPosition, boolean isExpanded,
    			View convertView, ViewGroup parent) {
    		if (convertView == null) {
    			GroupViewHolder groupViewHolder = new GroupViewHolder();
    			convertView = mInflater.inflate(R.layout.group_item, null);
    			groupViewHolder.tv_groupName = (TextView)convertView.findViewById(R.id.tv_group);
    			groupViewHolder.im_icon = (ImageView)convertView.findViewById(R.id.im_icon);
    			convertView.setTag(groupViewHolder);
    		}
    		GroupViewHolder gHolder = (GroupViewHolder) convertView.getTag();
    		String groupName = groupList.get(groupPosition);
    		if (groupName != null) {
    			gHolder.tv_groupName.setText(groupName);
    		}else {
    			gHolder.tv_groupName.setText("");
    		}
    		if (isExpanded) {
    			gHolder.im_icon.setBackgroundResource(R.drawable.icon2);
    		}else {
    			gHolder.im_icon.setBackgroundResource(R.drawable.icon);
    		}
    		return convertView;
    	}
    
    	@Override
    	public View getChildView(int groupPosition, int childPosition,
    			boolean isLastChild, View convertView, ViewGroup parent) {
    		if (convertView == null) {
    			ChildViewHolder cViewHolder = new ChildViewHolder();
    			convertView = mInflater.inflate(R.layout.child_item, null);
    			cViewHolder.tv_childName = (TextView)convertView.findViewById(R.id.tv_childName);
    			convertView.setTag(cViewHolder);
    		}
    		ChildViewHolder cHolder = (ChildViewHolder)convertView.getTag();
    		String childName = childList.get(groupPosition).get(childPosition);
    		if (childName != null) {
    			cHolder.tv_childName.setText(childName);
    		}else {
    			cHolder.tv_childName.setText("");
    		}
    		return convertView;
    	}
    
    	@Override
    	public boolean isChildSelectable(int groupPosition, int childPosition) {
    		return true;
    	}
    
    	private class GroupViewHolder{
    		private TextView tv_groupName;
    		private ImageView im_icon;
    	}
    	private class ChildViewHolder{
    		private TextView tv_childName;
    	}
    }

**6、怎么样，不难吧，group和child分的很明显，listView是一个布局，它需要两个布局，一个是父布局，一个子布局，**

**父布局代码：**

**子布局代码：**

<?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
    
        <ImageView
            android:id="@+id/im_headIcon"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:contentDescription="@string/headxiang"
            android:layout_marginLeft="42dp"
            android:layout_marginTop="5sp"
            android:src="@drawable/headxiang" />
    
        <TextView
            android:id="@+id/tv_childName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignTop="@+id/im_headIcon"
            android:layout_marginLeft="10dp"
            android:layout_toRightOf="@+id/im_headIcon"
            android:textStyle="bold"
            android:text="@string/tv_friendName"
            android:textSize="18sp" />
    
        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/tv_childName"
            android:layout_below="@+id/tv_childName"
            android:text="@string/tv_sign" />
    
    </RelativeLayout>

**7、最后，来看工程结构图：**

![Center 1][]  
**8、ok，好友列表完成，下一篇写聊天。**

[Center]: /images/20220810/0ca059cbda9c4fb0943b87f667424baf.png
[Center 1]: /images/20220810/a551bfb5db724ef79d000007b5f37f41.png