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" /> <> <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：
private boolean isFlingScroll; private View headView; private PullToRefreshListView lvHomeStore; initView(){ lvHomeStore = (PullToRefreshListView) view.findViewById(R.id.lv_home_store_list); lvHomeStore.setMode(PullToRefreshBase.Mode.BOTH); ListView listView = lvHomeStore.getRefreshableView(); headView = initHeadView(); AbsListView.LayoutParams layoutParams = new AbsListView.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 public void onScrollStateChanged(AbsListView view, int scrollState) { if (scrollState == SCROLL_STATE_FLING) {//手指离开手机界面，Listview还在滑动 isFlingScroll = true; } else if (scrollState == SCROLL_STATE_TOUCH_SCROLL) {//手指在界面上滚动的情况 isFlingScroll = false; } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { showSearchBarShow(); } private void showSearchBarShow() { int headBottomToParentTop = 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 int height = layoutSearch.getHeight(); Log.d("homeStore", "height: " + height); if (headBottomToParentTop > height) { layoutSearch.setVisibility(View.INVISIBLE); } else if (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。 float alpha = (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们留言，小编会及时回复大家的。在此也非常感谢大家对查字典教程网的支持！