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Android ExpandableListView的使用

日期：2017-11-20点击：444收藏

Android ExpandableListView的使用

一、MainActivity要继承ExpandableListActivity。效果是当单机ListView的子项是显示另一个ListView。

    public  class  MainActivity  extends  ExpandableListActivity { 
       
      private  static  final  String NAME =  "NAME" ; 
      private  static  final  String IS_EVEN =  "IS_EVEN" ; 
      private  ExpandableListAdapter eListAdapter; 
   
      @Override 
      protected  void  onCreate(Bundle savedInstanceState) { 
          super .onCreate(savedInstanceState); 
           
          List<Map<String,String>> groupData =  new  ArrayList<Map<String,String>>(); 
          List<List<Map<String, String>>> childDataList =  new  ArrayList<List<Map<String,String>>>(); 
          for  ( int  i =  0 ; i <  10 ; i++) { 
              Map<String, String> curGroupMap =  new  HashMap<String, String>(); 
              groupData.add(curGroupMap); 
              curGroupMap.put(NAME,  "Group" +i); 
              curGroupMap.put(IS_EVEN, (i% 2 == 0 )?  "This group is even" :  "This group is odd" ); 
               
              List<Map<String, String>> children =  new  ArrayList<Map<String,String>>(); 
              for  ( int  j =  0 ; j <  8 ; j++) { 
                  Map<String, String> curChildMap =  new  HashMap<String, String>(); 
                  children.add(curChildMap); 
                  curChildMap.put(NAME,  "Child"  + j); 
                  curChildMap.put(IS_EVEN, (j %  2  ==  0 ) ?  "This child is even"  :  "This child is odd"  ); 
              } 
              childDataList.add(children); 
          } 
          eListAdapter =  new  SimpleExpandableListAdapter( 
                  this ,  
                  groupData,  
                  android.R.layout.simple_expandable_list_item_2, 
                  new  String[] {NAME, IS_EVEN },  
                  new  int [] { android.R.id.text1, android.R.id.text2},  
                  childDataList,  
                  android.R.layout.simple_expandable_list_item_2,  
                  new  String[] {NAME, IS_EVEN},  
                  new  int [] { android.R.id.text1, android.R.id.text2}); 
           
          setListAdapter(eListAdapter); 
                   
      } 
 } 
 
  

代码解释

1、groupData是父数据，childDataList是子数据。

2、android.R.layout.simple_expandable_list_item_2表示list的实现方式

3、new String[] { NAME,IS_EVEN}list需要显示的数据。

效果图：

也就是单机Group2时，显示Group2的数据。

二、数据源：SimpleCursorTreeAdapter的使用

显示通讯录中的姓名，单击用姓名，显示号码。前提还要分配读取通讯录的权限

<uses-permission android:name= "android.permission.READ_CONTACTS" />

代码如下：

    public  class  ExpandableList2  extends  ExpandableListActivity {   
      private  int  mGroupIdColumnIndex;    
         
      private  String mPhoneNumberProjection[] =  new  String[] {   
              People.Phones._ID, People.Phones.NUMBER   
      };   
     
         
      private  ExpandableListAdapter mAdapter;   
         
   
      @Override  
      public  void  onCreate(Bundle savedInstanceState) {   
          super .onCreate(savedInstanceState);   
     
          // Query for people   
          Cursor groupCursor = managedQuery(People.CONTENT_URI,   
                  new  String[] {People._ID, People.NAME},  null ,  null ,  null );   
     
          // Cache the ID column index   
          mGroupIdColumnIndex = groupCursor.getColumnIndexOrThrow(People._ID);   
     
          // Set up our adapter   
          mAdapter =  new  MyExpandableListAdapter(groupCursor,   
                  this ,   
                  android.R.layout.simple_expandable_list_item_1,   
                 android.R.layout.simple_expandable_list_item_1,   
                  new  String[] {People.NAME},  // Name for group layouts   
                  new  int [] {android.R.id.text1},   
                  new  String[] {People.NUMBER},  // Number for child layouts   
                  new  int [] {android.R.id.text1});   
          setListAdapter(mAdapter);   
      }   
     
      public  class  MyExpandableListAdapter  extends  SimpleCursorTreeAdapter {   
     
          public  MyExpandableListAdapter(Cursor cursor, Context context,  int  groupLayout,   
                  int  childLayout, String[] groupFrom,  int [] groupTo, String[] childrenFrom,   
                  int [] childrenTo) {   
              super (context, cursor, groupLayout, groupFrom, groupTo, childLayout, childrenFrom,   
                      childrenTo);   
          }   
     
     
          @Override  
          protected  Cursor getChildrenCursor(Cursor groupCursor) {   
              // Given the group, we return a cursor for all the children within that group    
     
              // Return a cursor that points to this contact's phone numbers   
              Uri.Builder builder = People.CONTENT_URI.buildUpon();   
              ContentUris.appendId(builder, groupCursor.getLong(mGroupIdColumnIndex));   
              builder.appendEncodedPath(People.Phones.CONTENT_DIRECTORY);   
              Uri phoneNumbersUri = builder.build();   
     
              // The returned Cursor MUST be managed by us, so we use Activity's helper   
              // functionality to manage it for us.   
              return  managedQuery(phoneNumbersUri, mPhoneNumberProjection,  null ,  null ,  null );   
          }   
     
      }   
 
  

三、通过BaseExpandableListAdapter绑定数据

1.BaseExpandableListAdapter

    public  class  ExpandableList3  extends  Activity {   
     
      private  String[] groups = {  "group1" ,  "group2" ,  "group3" ,  "group4"  };   
      private  String[][] children = {   
              {  "g1 item1" ,  "g1 item2" ,  "g1 item3" ,  "g1 item4"  },   
              {  "g2 item1" ,  "g2 item2" ,  "g2 item3" ,  "g2 item4"  },   
              {  "g3 item1" ,  "g3 item2"  },   
              {  "g4 item1" ,  "g4 item2"  }   
      };   
      //ExpandableListAdapter mAdapter;   
      private  ExpandableListView expandableListView; 
      private  TextView tView =  null ;  
       
      @Override  
      public  void  onCreate(Bundle savedInstanceState) {   
          super .onCreate(savedInstanceState);   
     
          setContentView(R.layout.activity_main); 
           
          tView = (TextView)findViewById(R.id.textView1); 
          expandableListView = (ExpandableListView)findViewById(R.id.expandableListView1); 
           
          ExpandableListAdapter adapter =  new  BaseExpandableListAdapter() { 
       
              @Override 
              public  boolean  isChildSelectable( int  groupPosition,  int  childPosition) { 
                  // TODO Auto-generated method stub 
                  String string = groups[groupPosition] + children[groupPosition][childPosition]; 
                  tView.setText(string); 
                  return  true ; 
              } 
               
              @Override 
              public  boolean  hasStableIds() { 
                  // TODO Auto-generated method stub 
                  return  true ; 
              } 
               
              @Override 
              public  View getGroupView( int  groupPosition,  boolean  isExpanded, 
                      View convertView, ViewGroup parent) { 
                  // TODO Auto-generated method stub 
                  LinearLayout layout =  new  LinearLayout(ExpandableList3. this ); 
                  layout.setOrientation( 0 ); 
                  layout.setPadding( 50 ,  0 ,  0 ,  0 ); 
                  ImageView imageView =  new  ImageView(ExpandableList3. this ); 
                  imageView.setImageResource(R.drawable.ic_launcher); 
                  layout.addView(imageView); 
                   
                  TextView textView = getTextView(); 
                  textView.setText(getGroup(groupPosition).toString()); 
                  layout.addView(textView); 
                  return  layout; 
              } 
               
              private  TextView getTextView() { 
                  // TODO Auto-generated method stub 
                  AbsListView.LayoutParams lParams =  new  AbsListView.LayoutParams( 
                          ViewGroup.LayoutParams.FILL_PARENT,  64 ); 
                  TextView textView =  new  TextView(ExpandableList3. this ); 
                  textView.setLayoutParams(lParams); 
                  textView.setPadding( 20 ,  0 ,  0 ,  0 ); 
                  textView.setGravity(Gravity.LEFT | Gravity.CENTER_VERTICAL); 
                  return  textView; 
              } 
   
              @Override 
              public  long  getGroupId( int  groupPosition) { 
                  // TODO Auto-generated method stub 
                  return  groupPosition; 
              } 
               
              @Override 
              public  int  getGroupCount() { 
                  // TODO Auto-generated method stub 
                  return  groups.length; 
              } 
               
              @Override 
              public  Object getGroup( int  groupPosition) { 
                  // TODO Auto-generated method stub 
                  return  groups[groupPosition]; 
              } 
               
              @Override 
              public  int  getChildrenCount( int  groupPosition) { 
                  // TODO Auto-generated method stub 
                  return  children[groupPosition].length; 
              } 
               
              @Override 
              public  View getChildView( int  groupPosition,  int  childPosition, 
                      boolean  isLastChild, View convertView, ViewGroup parent) { 
                  // TODO Auto-generated method stub 
                  TextView textView  = getTextView(); 
                  textView.setText(getChild(groupPosition, childPosition).toString()); 
                  return  textView; 
              } 
               
              @Override 
              public  long  getChildId( int  groupPosition,  int  childPosition) { 
                  // TODO Auto-generated method stub 
                  return  childPosition; 
              } 
               
              @Override 
              public  Object getChild( int  groupPosition,  int  childPosition) { 
                  // TODO Auto-generated method stub 
                  return  children[groupPosition][childPosition]; 
              } 
               
               
          }; 
      
          expandableListView.setAdapter(adapter); 
      }   
         
 } 
 
  

效果图：点击子项时，显示子项的信息。

2.数据源写一个类MyExpandableListAdapter，该类继承自 BaseExpandableListAdapter。

    public  class  ExpandableList1  extends  ExpandableListActivity {   
     
      ExpandableListAdapter mAdapter;   
     
      @Override  
      public  void  onCreate(Bundle savedInstanceState) {   
          super .onCreate(savedInstanceState);   
     
          // Set up our adapter   
          mAdapter =  new  MyExpandableListAdapter();   
          setListAdapter(mAdapter);   
          // register context menu, when long click the item, it will show a dialog   
          registerForContextMenu(getExpandableListView());   
      }   
         
      @Override  
      public  boolean  onContextItemSelected(MenuItem item) {   
          ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo();   
     
          String title = ((TextView) info.targetView).getText().toString();   
             
          int  type = ExpandableListView.getPackedPositionType(info.packedPosition);   
          if  (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {   
              int  groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);    
              int  childPos = ExpandableListView.getPackedPositionChild(info.packedPosition);    
              Toast.makeText( this , title +  ": Child "  + childPos +  " clicked in group "  + groupPos,   
                      Toast.LENGTH_SHORT).show();   
              return  true ;   
          }  else  if  (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {   
              int  groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);    
              Toast.makeText( this , title +  ": Group "  + groupPos +  " clicked" , Toast.LENGTH_SHORT).show();   
              return  true ;   
          }   
             
          return  false ;   
      }   
     
      /**  
       * A simple adapter which maintains an ArrayList of photo resource Ids.   
       * Each photo is displayed as an image. This adapter supports clearing the  
       * list of photos and adding a new photo.  
       *  
       */  
      public  class  MyExpandableListAdapter  extends  BaseExpandableListAdapter {   
          // Sample data set.  children[i] contains the children (String[]) for groups[i].   
          private  String[] groups = {  "People Names" ,  "Dog Names" ,  "Cat Names" ,  "Fish Names"  };   
          private  String[][] children = {   
                  {  "Arnold" ,  "Barry" ,  "Chuck" ,  "David"  },   
                  {  "Ace" ,  "Bandit" ,  "Cha-Cha" ,  "Deuce"  },   
                  {  "Fluffy" ,  "Snuggles"  },   
                  {  "Goldy" ,  "Bubbles"  }   
          };   
             
          public  Object getChild( int  groupPosition,  int  childPosition) {   
              return  children[groupPosition][childPosition];   
          }   
     
          public  long  getChildId( int  groupPosition,  int  childPosition) {   
              return  childPosition;   
          }   
     
          public  int  getChildrenCount( int  groupPosition) {   
              return  children[groupPosition].length;   
          }   
     
          public  TextView getGenericView() {   
              // Layout parameters for the ExpandableListView   
              AbsListView.LayoutParams lp =  new  AbsListView.LayoutParams(   
                      ViewGroup.LayoutParams.FILL_PARENT,  64 );   
     
              TextView textView =  new  TextView(ExpandableList1. this );   
              textView.setLayoutParams(lp);   
              // Center the text vertically   
              textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);   
              // Set the text starting position   
              textView.setPadding( 36 ,  0 ,  0 ,  0 );   
              return  textView;   
          }   
             
          public  View getChildView( int  groupPosition,  int  childPosition,  boolean  isLastChild,   
                  View convertView, ViewGroup parent) {   
              TextView textView = getGenericView();   
              textView.setText(getChild(groupPosition, childPosition).toString());   
              return  textView;   
         }   
    
          public  Object getGroup( int  groupPosition) {   
              return  groups[groupPosition];   
          }   
     
         public  int  getGroupCount() {   
             return  groups.length;   
         }   
    
          public  long  getGroupId( int  groupPosition) {   
              return  groupPosition;   
          }   
     
         public  View getGroupView( int  groupPosition,  boolean  isExpanded, View convertView,   
                 ViewGroup parent) {   
             TextView textView = getGenericView();   
              textView.setText(getGroup(groupPosition).toString());   
              return  textView;   
          }   
     
        public  boolean  isChildSelectable( int  groupPosition,  int  childPosition) {   
              return  true ;   
          }   
    
          public  boolean  hasStableIds() {   
             return  true ;   
          }   
     
      }   
 }  
 
  