Android开发之ListView的head消失页面导航栏的渐变出现和隐藏
1.Fragment页面xml布局：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" xmlns:ptr="http://schemas.android.com/apk/res-auto" tools:context=".fragment.home.HomeStoreFragment" > <com.handmark.pulltorefresh.library.PullToRefreshListView android:id="@+id/lv_home_store_list" android:layout_width="match_parent" android:layout_height="match_parent" ptr:ptrDrawable="@drawable/default_ptr_flip" ptr:ptrAnimationStyle="flip" /> <!--top搜索栏--> <LinearLayout android:id="@+id/ll_top_search" android:layout_width="match_parent" android:layout_height="60dp" android:background="@color/zuti" android:visibility="invisible" > <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:layout_marginLeft="15dp" android:layout_marginRight="15dp" android:layout_marginTop="8dp" android:layout_marginBottom="8dp" android:background="@drawable/shape_edit_cornor" android:gravity="center" > <ImageView android:id="@+id/iv_search_icon" android:layout_width="30dp" android:layout_height="30dp" android:src="@drawable/icon_navbar_search" android:layout_marginRight="5dp" /> <EditText android:id="@+id/et_store_search" android:layout_width="wrap_content" android:layout_height="wrap_content" android:hint="输入商家或商品名" android:textColorHint="@color/shenhui" android:background="@null" /> </LinearLayout> </LinearLayout> </RelativeLayout>
2.主要代码：
privatebooleanisFlingScroll;
privateViewheadView;
privatePullToRefreshListViewlvHomeStore;
initView(){
lvHomeStore=(PullToRefreshListView)view.findViewById(R.id.lv_home_store_list);
lvHomeStore.setMode(PullToRefreshBase.Mode.BOTH);
ListViewlistView=lvHomeStore.getRefreshableView();
headView=initHeadView();
AbsListView.LayoutParamslayoutParams=newAbsListView.LayoutParams(AbsListView.LayoutParams.MATCH_PARENT,AbsListView.LayoutParams.WRAP_CONTENT);//这句要加上去
headView.setLayoutParams(layoutParams);
listView.addHeaderView(headView);
lvHomeStore.setAdapter(adapter);
lvHomeStore.setOnScrollListener(this);
}
@Override
publicvoidonScrollStateChanged(AbsListViewview,intscrollState){
if(scrollState==SCROLL_STATE_FLING){//手指离开手机界面，Listview还在滑动
isFlingScroll=true;
}elseif(scrollState==SCROLL_STATE_TOUCH_SCROLL){//手指在界面上滚动的情况
isFlingScroll=false;
}
}
@Override
publicvoidonScroll(AbsListViewview,intfirstVisibleItem,intvisibleItemCount,inttotalItemCount){
showSearchBarShow();
}
privatevoidshowSearchBarShow(){
intheadBottomToParentTop=headView.getHeight()+headView.getTop();
Log.d("homeStore","headView.getHeight():"+headView.getHeight());
Log.d("homeStore","headView.getTop():"+headView.getTop());
Log.d("homeStore","headBottomToParentTop:"+headBottomToParentTop);
if(!isFlingScroll){//手指在界面滑动的情况
intheight=layoutSearch.getHeight();
Log.d("homeStore","height:"+height);
if(headBottomToParentTop>height){
layoutSearch.setVisibility(View.INVISIBLE);
}elseif(headBottomToParentTop<=height){//缓慢滑动，这部分代码工作正常，快速滑动，里面的数据就跟不上节奏了。
floatalpha=(height-headBottomToParentTop)*1f/height;
Log.d("homeStore","alpha:"+alpha);
layoutSearch.setAlpha(alpha);
layoutSearch.setVisibility(View.VISIBLE);
}
if(!headView.isShown()){//解决快速滑动，上部分代码不能正常工作的问题。
layoutSearch.setAlpha(1);
layoutSearch.setVisibility(View.VISIBLE);
}
}else{//手指离开，listview还在滑动，一般情况是列表快速滑动，这种情况直接设置导航栏的可见性
if(!headView.isShown()){
if(!layoutSearch.isShown()){
layoutSearch.setVisibility(View.VISIBLE);
layoutSearch.setAlpha(1);
}
}else{
if(layoutSearch.isShown()){
layoutSearch.setVisibility(View.INVISIBLE);
}
}
}
}
以上所述是小编给大家介绍的Android开发之ListView的head消失页面导航栏的渐变出现和隐藏，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对毛票票网站的支持！