Android学习笔记之ExpandableListView 三级

在做三级列表的时候，用的是ExpandableListView里套一个ExpandableListView，由于里面的ExpandableListView把图标隐藏了……点又点不开，就以为是里面的ExpandableListView失效，弄了三小时，才想到把图标显示出来，，结果……已经打开了，郁闷得要死了，，，然后知道是因为没有位置的原因了……哎，，记下，别以后还杨白劳三个小时……

public class EGuideFourAdapter extends BaseExpandableListAdapter {
	private Context mContext;
	private List<NamedList> list;

	public EGuideFourAdapter(Context context, List<NamedList> list) {
		this.list = list;
		this.mContext = context;
	}

	@Override
	public Object getChild(int groupPosition, int childPosition) {
		// TODO Auto-generated method stub
		return list.get(groupPosition).getChildList().get(childPosition);
	}

	@Override
	public long getChildId(int groupPosition, int childPosition) {
		// TODO Auto-generated method stub
		return childPosition;
	}

	static public TextView getTextView(Context context) {// 控制所有级的菜单，如果各级有另外设置，实现的是另外的设置。
		AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
				ViewGroup.LayoutParams.FILL_PARENT, 90);
		TextView textView = new TextView(context);
		textView.setLayoutParams(lp);
		textView.setTextSize(17);
		textView.setTextColor(Color.BLACK);
		textView.setPadding(10, 5, 0, 5);
		textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
		return textView;
	}

	/**
	 * 三层树结构中的第二层是一个ExpandableListView
	 */
	public View getChildView(final int groupPosition, final int childPosition,
			boolean isLastChild, View convertView, ViewGroup parent) {
		if (list.get(groupPosition).getChildList().get(childPosition)
				.getChildList().size() > 0) {// 该项是否有第三级
			// 是
			final ExpandableListView examGuidView = getExpandableListView();
			examGuidView.setGroupIndicator(null);
			examGuidView.setPadding(pixelsToDip(mContext,25), 0, 0, 0);
			final ExamGuideAdapter examGuideAdapter = new ExamGuideAdapter(
					this.mContext, list.get(groupPosition).getChildList());
			// list.get(groupPosition).getChildList()为第二级的list
			examGuidView.setAdapter(examGuideAdapter);
			// 点击第三级时，
			examGuidView.setOnChildClickListener(new OnChildClickListener() {

				@Override
				public boolean onChildClick(ExpandableListView parent, View v,
						int groupPositionTwo, int childPosition, long id) {

					// 获取第四级列表项
					List<NamedList> eGlist = list.get(groupPosition)
							.getChildList().get(groupPositionTwo)
							.getChildList().get(childPosition).getChildList();
					// 获取第三级标题
					String title = list.get(groupPosition).getChildList()
							.get(groupPositionTwo).getChildList()
							.get(childPosition).getName();
					if (eGlist.size() > 0) {// 第四级不是详细内容
						Intent intent = new Intent(mContext,
								UIExamGuideFour.class);
						intent.putExtra("list", (Serializable) eGlist);
						intent.putExtra("title", title);
						mContext.startActivity(intent);
					} else {
						Intent intent = new Intent(mContext,
								UIExamGuideContent.class);
						intent.putExtra("title", title);
						mContext.startActivity(intent);
					}
					return false;
				}
			});

			/**
			 * 重点：没有这个方法第三级会没有位置，所以会看不到，误以为ExpandableListView失效
			 * 关键点：第二级菜单展开时通过取得节点数来设置第三级菜单的大小
			 */
			examGuidView.setOnGroupExpandListener(new OnGroupExpandListener() {
				int i = 0;

				@Override
				public void onGroupExpand(int groupPosition) {
					i = (list.get(groupPosition).getChildList()
							.get(childPosition).getChildList().size() + 1) * 90 + 30;
					AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
							ViewGroup.LayoutParams.FILL_PARENT, i);
					examGuidView.setLayoutParams(lp);
				}
			});
			/**
			 * 第二级菜单回收时设置为标准Item大小
			 */
			examGuidView
					.setOnGroupCollapseListener(new OnGroupCollapseListener() {

						@Override
						public void onGroupCollapse(int groupPosition) {
							AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
									ViewGroup.LayoutParams.FILL_PARENT, 90);
							examGuidView.setLayoutParams(lp);
						}
					});
			return examGuidView;
		} else {
			TextView textView = getTextView(mContext);
			ExamGuide named = (ExamGuide) list.get(groupPosition)
					.getChildList().get(childPosition);
			textView.setTextColor(Color.BLACK);
			textView.setText(named.getName());
			// textView.setTag(temp[1]);
			// textView.setText(getChild(groupPosition,
			// childPosition).toString());
			textView.setPadding(pixelsToDip(mContext,55), 0, 0, 0);// 第一个参数原来为：
												// myPaddingLeft+PaddingLeft
												// ，是设置第三级菜单文字离左边的距离。
			return textView;
		}
	}

	public ExpandableListView getExpandableListView() {
		AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
				ViewGroup.LayoutParams.FILL_PARENT, 90);
		ExpandableListView superTreeView = new ExpandableListView(mContext);
		superTreeView.setLayoutParams(lp);
		return superTreeView;
	}

	public View getGroupView(int groupPosition, boolean isExpanded,
			View convertView, ViewGroup parent) {
		TextView textView = getTextView(mContext);
		ExamGuide named = (ExamGuide) list.get(groupPosition);
		textView.setText(named.getName());
		textView.setPadding(pixelsToDip(mContext,40), 0, 0, 0);// 第一个参数原来为：myPaddingLeft+(PaddingLeft>>1)
											// ，是设置第二级菜单文字离左边的距离。
		textView.setTextColor(Color.BLACK);
		return textView;
	}
	//像素转dip解决分辨率问题
    private  int pixelsToDip(Context context,int Pixels) {
            int dip=(int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, Pixels, context.getResources().getDisplayMetrics());
            return dip;
    }

	/**
	 * 第二级点击打开第三级
	 * 
	 * @param examGuidView
	 * @param groupPosition
	 */
	public void clickEvent(ExpandableListView examGuidView, int groupPosition) {
		examGuidView.expandGroup(groupPosition);
	}

	@Override
	public int getChildrenCount(int groupPosition) {
		// TODO Auto-generated method stub
		return list.get(groupPosition).getChildList().size();
	}

	@Override
	public Object getGroup(int groupPosition) {
		// TODO Auto-generated method stub
		return list.get(groupPosition);
	}

	@Override
	public int getGroupCount() {
		// TODO Auto-generated method stub
		return list.size();
	}

	@Override
	public long getGroupId(int groupPosition) {
		// TODO Auto-generated method stub
		return groupPosition;
	}

	@Override
	public boolean hasStableIds() {
		// TODO Auto-generated method stub
		return false;
	}

	@Override
	public boolean isChildSelectable(int p, int id) {
		// TODO Auto-generated method stub
		return true;
	}

 

评论

2 楼 IWSo 2013-09-03  

  i = (list.get(groupPosition).getChildList() 
                            .get(childPosition).getChildList().size() + 1) * 90 + 30; 

这个值为什么是这么算的？
“* 90 + 30;”为什么是乘以加30而不是其他数值？

1 楼 IWSo 2013-09-03  

i = (list.get(groupPosition).getChildList() 
                            .get(childPosition).getChildList().size() + 1) * 90 + 30; 
                    AbsListView.LayoutParams lp = new AbsListView.LayoutParams( 
                            ViewGroup.LayoutParams.FILL_PARENT, i); 
                    examGuidView.setLayoutParams(lp); 

这段代码的作用是什么？
为什么将i换成ViewGroup.LayoutParams.FILL_PARENT就不行呢