控件 -- ScrollView
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参考技术A ScrollView是一种特殊的布局控件，当ScrollView的内容大于它本身的大小时，ScrollView会自动添加滚动条，并可以竖直滑动。● ScrollView的直接子View只能有一个，也就是说如果要使用很复杂的视图结构，就必须把这些视图放在一个标准布局里，如LinearLayout、RelativeLayout等。
● 可以使用layout_width和layout_height给ScrollView指定大小。
● ScrollView只用来处理需要滚动的不规则视图的组合，大批量的列表数据展示可以使用ListView、GridView或者RecyclerView。
● ScrollView和ListView之类的嵌套使用时会有滑动冲突，不到不得已不要使用。
● ScrollView只支持竖直滑动，水平滑动使用HorizontalScrollView。
● ScrollView的android:fillViewport属性定义了是否可以拉伸其内容来填满viewport，可以调用方法setFillViewport(boolean)来达到一样的效果。
解决下拉刷新控件和ScrollVIew的滑动冲突问题。
最近项目要实现ScrollView中嵌套广告轮播图+RecyleView卡片布局，并且RecyleView按照header和内容的排列样式，因为RecyleView的可扩展性很强，所以我毫无疑问的选择了它，而且让RecyleView实现了可拖拽的效果，
最后我再加上了下拉刷新的效果(这里我用的下拉刷新控件是三方的SmartRefreshLayout)。记得刚开始实现这个效果的时候还是十分的得心印手。可是当我测试的时候，发现RecyleView的子item的拖拽效果并不流畅，起初我以
为是由于RecyleView和ScrollView的滑动冲突导致的，可是慢慢我自己重新写了个demo，逐步调试，发现肯定是下拉刷新控件和ScrollView的原因造成的，于是对症下药，终于找到了解决的办法，这里将我的答案记录下来，为了
后面其他的人遇到和我一样的问题，避免他们走很多的弯路，希望会对他们有所帮助，当然把自己遇到问题和解决问题的办法都记录下来，这对自己来说也是一种成长。如果有其他更好的思路，希望给我留言，谢谢。
解决办法一:
在布局页面中把ScrollView控件换成NestedScrollView控件：
对NestedScrollView的详解:http://www.cnblogs.com/skytwo/p/4613912.html
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
..............
</android.support.v4.widget.NestedScrollView>
以下是简单demo：
MainActivity:用底部BottomNavigationBar，实现viewpager和fragment连用
代码:
public class MainActivity extends AppCompatActivity implements BottomNavigationBar.OnTabSelectedListener,ViewPager.OnPageChangeListener{
private ViewPager viewPager;
private BottomNavigationBar bottomNavigationBar;
//存放fragment的集合
private Fragment[] fragments;
//切换不同fragment用的下标
private int index;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initBottomNavigationBar();
initViewPager();
}
//初始化底部导航菜单
private void initBottomNavigationBar() {
bottomNavigationBar = (BottomNavigationBar) findViewById(R.id.bottom_navigation_bar);
bottomNavigationBar.setTabSelectedListener(this);
bottomNavigationBar.clearAll();
bottomNavigationBar.setMode(BottomNavigationBar.MODE_FIXED);
bottomNavigationBar.setBackgroundStyle(BottomNavigationBar.BACKGROUND_STYLE_STATIC);
bottomNavigationBar.addItem(new BottomNavigationItem(R.drawable.ic_launcher,"主页").setInactiveIconResource(R.drawable.ic_launcher).setActiveColorResource(R.color.colorPrimaryDark))
.addItem(new BottomNavigationItem(R.drawable.ic_launcher,"单据").setInactiveIconResource(R.drawable.ic_launcher).setActiveColorResource(R.color.colorPrimaryDark))
.addItem(new BottomNavigationItem(R.drawable.ic_launcher, "审核").setInactiveIconResource(R.drawable.ic_launcher).setActiveColorResource(R.color.colorPrimaryDark))
.addItem(new BottomNavigationItem(R.drawable.ic_launcher, "报表").setInactiveIconResource(R.drawable.ic_launcher).setActiveColorResource(R.color.colorPrimaryDark))
.addItem(new BottomNavigationItem(R.drawable.ic_launcher,"设置").setInactiveIconResource(R.drawable.ic_launcher).setActiveColorResource(R.color.colorPrimaryDark))
.initialise();
}
//初始化viewpager
private void initViewPager() {
viewPager = (ViewPager) findViewById(R.id.view_pager);
fragments = new Fragment[5];
fragments[0]=new FragOne();
fragments[1]=new FragTwo();
fragments[2]=new FragThree();
fragments[3]=new FragFour();
fragments[4]=new FragFive();
viewPager.setOffscreenPageLimit(4);
viewPager.setAdapter(new SectionsPagerAdapter(getSupportFragmentManager(), fragments));
viewPager.addOnPageChangeListener(this);
viewPager.setCurrentItem(0);
}
@Override
public void onTabSelected(int position) {
viewPager.setCurrentItem(position);
}
@Override
public void onTabUnselected(int position) {
}
@Override
public void onTabReselected(int position) {
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int i) {
bottomNavigationBar.selectTab(i);
this.index = i;
}
@Override
public void onPageScrollStateChanged(int state) {
}
class SectionsPagerAdapter extends FragmentPagerAdapter {
Fragment fragments[]=new Fragment[4];
public SectionsPagerAdapter(FragmentManager fm, Fragment fragments[]) {
super(fm);
this.fragments = fragments;
}
@Override
public Fragment getItem(int position) {
return fragments[position];
}
@Override
public int getCount() {
return fragments.length;
}
}
}
MainActity布局：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.admin.demo.MainActivity">
<android.support.v4.view.ViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
/>
<com.ashokvarma.bottomnavigation.BottomNavigationBar
android:id="@+id/bottom_navigation_bar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
/>
</LinearLayout>
主fragment:实现下拉刷新、上拉加载、RecyleView拖拽等各种效果的fragment
public class FragOne extends Fragment implements MyItemTouchCallback.OnDragListener {
private List<String> list = new ArrayList<String>();
private View parent;
//显示模块的recyleview
private RecyclerView mRecyclerView;
//可拖动模块的帮助类
private ItemTouchHelper itemTouchHelper;
//适配器
private RecyleViewAdapter mRecyclerAdapter;
//声明刷新控件
private SmartRefreshLayout srf;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
parent = inflater.inflate(R.layout.frag_one, container, false);
initView();
return parent;
}
private void initView() {
for (int i = 0; i < 100; i++) {
list.add(i + "");
}
mRecyclerView = (RecyclerView) parent.findViewById(recyclerView);
// 设置添加删除item的时候的动画效果
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
GridLayoutManager gridLayoutManager = new GridLayoutManager(getActivity(), 4);
gridLayoutManager.setSmoothScrollbarEnabled(true);
gridLayoutManager.setAutoMeasureEnabled(true);
mRecyclerView.setLayoutManager(gridLayoutManager);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setNestedScrollingEnabled(false);
// 设置适配器
mRecyclerAdapter = new RecyleViewAdapter(list);
itemTouchHelper = new ItemTouchHelper(new MyItemTouchCallback(mRecyclerAdapter).setOnDragListener(this));
itemTouchHelper.attachToRecyclerView(mRecyclerView);
mRecyclerView.setAdapter(mRecyclerAdapter);
mRecyclerView.addOnItemTouchListener(new OnRecyclerItemClickListener(mRecyclerView) {
@Override
public void onLongClick(RecyclerView.ViewHolder vh) {
itemTouchHelper.startDrag(vh);
VibratorUtil.Vibrate(getActivity(), 70); //震动70ms
}
@Override
public void onItemClick(RecyclerView.ViewHolder vh) {
super.onItemClick(vh);
}
});
srf = (SmartRefreshLayout) parent.findViewById(R.id.refresh);
srf.setDefaultRefreshHeaderCreater(new DefaultRefreshHeaderCreater() {
@Override
public RefreshHeader createRefreshHeader(Context context, RefreshLayout layout) {
return new ClassicsHeader(context);//指定为经典Header，默认是 贝塞尔雷达Header
}
});
srf.setOnRefreshListener(new OnRefreshListener() {
@Override
public void onRefresh(RefreshLayout refreshlayout) {
srf.postDelayed(new Runnable() {
@Override
public void run() {
mRecyclerAdapter.notifyDataSetChanged();
srf.finishRefresh();
Toast.makeText(getActivity(), "刷新成功", Toast.LENGTH_SHORT).show();
}
}, 3000);
}
});
srf.setEnableLoadmore(false);//屏蔽掉上拉加载的效果
}
@Override
public void onFinishDrag() {
}
class RecyleViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements MyItemTouchCallback.ItemTouchAdapter {
private List<String> mData;
public RecyleViewAdapter(List<String> data) {
mData = data;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new TestViewHolder(View.inflate(parent.getContext(), R.layout.item_test, null));
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
TestViewHolder tHolder = (TestViewHolder) holder;
tHolder.tv.setText(mData.get(position));
}
@Override
public int getItemCount() {
return mData == null ? 0 : mData.size();
}
@Override
public void onMove(int fromPosition, int toPosition) {
if (fromPosition < toPosition) {
for (int i = fromPosition; i < toPosition; i++) {
Collections.swap(mData, i, i + 1);
}
} else {
for (int i = fromPosition; i > toPosition; i--) {
Collections.swap(mData, i, i - 1);
}
}
notifyItemMoved(fromPosition, toPosition);
}
@Override
public void onSwiped(int position) {
mData.remove(position);
notifyItemRemoved(position);
}
private class TestViewHolder extends RecyclerView.ViewHolder {
TextView tv;
public TestViewHolder(View itemView) {
super(itemView);
tv = (TextView) itemView.findViewById(R.id.tv);
}
}
}
主fragment布局:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.scwang.smartrefresh.layout.SmartRefreshLayout
android:id="@+id/refresh"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/test" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:descendantFocusability="blocksDescendants">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"></android.support.v7.widget.RecyclerView>
</RelativeLayout>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
</com.scwang.smartrefresh.layout.SmartRefreshLayout>
</LinearLayout>
RecyleView实现可拖拽效果的帮助类:
MyItemTouchCallback :public class MyItemTouchCallback extends ItemTouchHelper.Callback {
private ItemTouchAdapter itemTouchAdapter;
public MyItemTouchCallback(ItemTouchAdapter itemTouchAdapter){
this.itemTouchAdapter = itemTouchAdapter;
}
@Override
public boolean isLongPressDragEnabled() {
return false;
}
@Override
public boolean isItemViewSwipeEnabled() {
return true;
}
@Override
public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
if (recyclerView.getLayoutManager() instanceof GridLayoutManager) {
final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN |
ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
final int swipeFlags = 0;
return makeMovementFlags(dragFlags, swipeFlags);
} else {
final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
final int swipeFlags = 0;
return makeMovementFlags(dragFlags, swipeFlags);
}
}
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
int fromPosition = viewHolder.getAdapterPosition();//得到拖动ViewHolder的position
int toPosition = target.getAdapterPosition();//得到目标ViewHolder的position
itemTouchAdapter.onMove(fromPosition,toPosition);
return true;
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
int position = viewHolder.getAdapterPosition();
itemTouchAdapter.onSwiped(position);
}
@Override
public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) {
//滑动时改变Item的透明度
final float alpha = 1 - Math.abs(dX) / (float) viewHolder.itemView.getWidth();
viewHolder.itemView.setAlpha(alpha);
viewHolder.itemView.setTranslationX(dX);
} else {
super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
}
@Override
public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
if (background == null && bkcolor == -1) {
Drawable drawable = viewHolder.itemView.getBackground();
if (drawable == null) {
bkcolor = 0;
} else {
background = drawable;
}
}
viewHolder.itemView.setBackgroundColor(Color.LTGRAY);
}
super.onSelectedChanged(viewHolder, actionState);
}
@Override
public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
super.clearView(recyclerView, viewHolder);
viewHolder.itemView.setAlpha(1.0f);
if (background != null) viewHolder.itemView.setBackgroundDrawable(background);
if (bkcolor != -1) viewHolder.itemView.setBackgroundColor(bkcolor);
//viewHolder.itemView.setBackgroundColor(0);
if (onDragListener!=null){
onDragListener.onFinishDrag();
}
}
private Drawable background = null;
private int bkcolor = -1;
private OnDragListener onDragListener;
public MyItemTouchCallback setOnDragListener(OnDragListener onDragListener) {
this.onDragListener = onDragListener;
return this;
}
public interface OnDragListener{
void onFinishDrag();
}
public interface ItemTouchAdapter {
void onMove(int fromPosition, int toPosition);
void onSwiped(int position);
}
}
OnRecyclerItemClickListener:
public class OnRecyclerItemClickListener implements RecyclerView.OnItemTouchListener{
private GestureDetectorCompat mGestureDetector;
private RecyclerView recyclerView;
public OnRecyclerItemClickListener(RecyclerView recyclerView){
this.recyclerView = recyclerView;
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