模仿QQ好友列表的ExpandableListView实现的效果

/** * */ package com.jgx.Exlistview; import android.content.Context; import android.graphics.Canvas; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.util.Log; import android.widget.*; import android.view.*; import android.view.ViewGroup.LayoutParams; import android.view.ViewGroup.MarginLayoutParams; /** * @author Jigx * */ public class QExpandedListView extends ExpandableListView implements View.OnClickListener, AbsListView.OnScrollListener{ @Override protected void dispatchDraw(Canvas canvas) { Log.i("jgx","dispatchDraw Start"); super.dispatchDraw(canvas); Log.i("jgx","dispatchDraw end"); } /** * @param context */ public QExpandedListView(Context context) { super(context); mContext = context; this.isFixGroup = true; super.setOnScrollListener(this); } /** * @param context * @param attrs */ public QExpandedListView(Context context, AttributeSet attrs) { super(context, attrs); mContext = context; this.isFixGroup = true; super.setOnScrollListener(this); } /** * @param context * @param attrs * @param defStyle */ public QExpandedListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); mContext = context; this.isFixGroup = true; super.setOnScrollListener(this); } @Override public void onClick(View v) { // TODO Auto-generated method stub } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { if(isFixGroup){//是否显示固定组头 boolean isFrameLayoutParent = getParent() instanceof RelativeLayout; mAdapter = this.getExpandableListAdapter(); if(isFrameLayoutParent){//当前listview是放到FrameLayout的容器中 parentLayout = (RelativeLayout)getParent(); QExpandedListView listView = (QExpandedListView)view; //得到当前listview if(null==indicatorGroup){ indicatorGroup = new LinearLayout(mContext); indicatorGroup.setBackgroundColor(0xFFFF88AA); parentLayout.addView(indicatorGroup, new MarginLayoutParams(LayoutParams.FILL_PARENT,ViewGroup.LayoutParams.WRAP_CONTENT)); Log.i("iphone","indicatorGroup addView"); } int npos = view.pointToPosition(0,0); if(npos != AdapterView.INVALID_POSITION){ long pos = listView.getExpandableListPosition(npos); int childPos = ExpandableListView.getPackedPositionChild(pos); int groupPos = ExpandableListView.getPackedPositionGroup(pos); if(childPos == AdapterView.INVALID_POSITION){ View groupView = listView.getChildAt(npos - listView.getFirstVisiblePosition()); indicatorGroupHeight = groupView.getHeight(); } // get an error data, so return now if(indicatorGroupHeight == 0){ return; } // update the data of indicator group view if(groupPos != indicatorGroupId){ Log.e("iphone"," iphone ExListView : " + "bind to new group,group position = " + groupPos); if(mAdapter!=null){ FixGroupView= mAdapter.getGroupView(groupPos,false,null, indicatorGroup); indicatorGroupId = groupPos; ((exObjAdapter)mAdapter).hideGroup(indicatorGroupId); // we set this group view to be hided ((exObjAdapter)mAdapter).notifyDataSetChanged();// .notifyDataSetChanged(); } } } if(indicatorGroupId == -1){ return; } /** * calculate point (0,indicatorGroupHeight) */ int showHeight = indicatorGroupHeight; int nEndPos = listView.pointToPosition(0,indicatorGroupHeight); if(nEndPos != AdapterView.INVALID_POSITION){ long pos = listView.getExpandableListPosition(nEndPos); int groupPos = ExpandableListView.getPackedPositionGroup(pos); if(groupPos != indicatorGroupId){ View viewNext = listView.getChildAt(nEndPos-listView.getFirstVisiblePosition()); showHeight = viewNext.getTop(); //Log.e(TAG,PRE + "update the show part height of indicator group:" + showHeight); } } if(FixGroupView.getParent()==null){ indicatorGroup.removeAllViews(); indicatorGroup.addView(FixGroupView); Log.i("iphone","indicatorGroup add View"); } // update group position ViewGroup.LayoutParams vlparams = indicatorGroup.getLayoutParams(); if((null!=vlparams)&&(vlparams instanceof MarginLayoutParams)){ MarginLayoutParams layoutParams = (MarginLayoutParams)vlparams; layoutParams.topMargin = -(indicatorGroupHeight-showHeight); Log.i("iphone"," top margin:"+layoutParams.topMargin); indicatorGroup.setLayoutParams(layoutParams); } else if(null!=vlparams) { Log.i("iphone"," layout class:"+vlparams.getClass().toString()); } else { Log.i("iphone"," layout class is null"); } } } if (this.mOnScrollListener != null) this.mOnScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount); } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { if (this.mOnScrollListener != null) this.mOnScrollListener.onScrollStateChanged(view, scrollState); } public void setOnScrollListener(AbsListView.OnScrollListener paramOnScrollListener) { this.mOnScrollListener = paramOnScrollListener; } public void setAdapter(ExpandableListAdapter paramExpandableListAdapter) { super.setAdapter(paramExpandableListAdapter); } private RelativeLayout parentLayout=null; //listview所在的父层对象 private boolean isFixGroup=true; //是否要固定显示组名在上边 private View FixGroupView=null; //始终固定显示的组view private ExpandableListAdapter mAdapter; private AbsListView.OnScrollListener mOnScrollListener=null; private int indicatorGroupId=-1; //当前固定显示的组索引 private int indicatorGroupHeight=0; private LinearLayout indicatorGroup; private Context mContext; }