Android初级教程_用ExpandableListView实现类似QQ好友列表

我们知道QQ好友列表分类使用ExpandableListView实现的,但是它在此基础上做改进,如打开分组,滑动时组标题会悬浮在最上端.

方便用户关闭分组.效果类似于下图:

实现代码如下所示:

[java] view plain copy

@Override
publicvoidonScroll(AbsListViewview,intfirstVisibleItem,
intvisibleItemCount,inttotalItemCount){
//防止三星,魅族等手机第一个条目可以一直往下拉,父条目和悬浮同时出现的问题
if(firstVisibleItem==0){
view_flotage.setVisibility(View.GONE);
}
//控制滑动时TextView的显示与隐藏
intnpos=view.pointToPosition(0,0);
if(npos!=AdapterView.INVALID_POSITION){
longpos=expandableList.getExpandableListPosition(npos);
intchildPos=ExpandableListView.getPackedPositionChild(pos);
finalintgroupPos=ExpandableListView.getPackedPositionGroup(pos);
if(childPos==AdapterView.INVALID_POSITION){
ViewgroupView=expandableList.getChildAt(npos
-expandableList.getFirstVisiblePosition());
indicatorGroupHeight=groupView.getHeight();
}
if(indicatorGroupHeight==0){
return;
}
//if(isExpanded){
if(count_expand>0){
the_group_expand_position=groupPos;
group_content.setText(groupData.get(the_group_expand_position)
.get("group_text"));
if(the_group_expand_position!=groupPos||!expandableList.isGroupExpanded(groupPos)){
view_flotage.setVisibility(View.GONE);
}else{
view_flotage.setVisibility(View.VISIBLE);
}
}
if(count_expand==0){
view_flotage.setVisibility(View.GONE);
}
}
if(the_group_expand_position==-1){
return;
}
/**
*calculatepoint(0,indicatorGroupHeight)
*/
intshowHeight=getHeight();
MarginLayoutParamslayoutParams=(MarginLayoutParams)view_flotage
.getLayoutParams();
//得到悬浮的条滑出屏幕多少
layoutParams.topMargin=-(indicatorGroupHeight-showHeight);
view_flotage.setLayoutParams(layoutParams);
}

有的手机品牌不一样可能会出现如下情况:

所以需要加上如下代码:

[java] view plain copy

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最近有些网友需要代码,现在附上下载地址.http://download.csdn.net/detail/johnny901114/4513242

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