android一个向上滑动显示菜单，向下滑动隐藏菜单实现，android滑动,浏览器qq猎豹等，很多都

android一个向上滑动显示菜单，向下滑动隐藏菜单实现，android滑动,浏览器qq猎豹等，很多都

浏览器qq猎豹等，很多都是，向上滑动显示搜索菜单，向下浏览网页隐藏搜索菜单，而且非常平滑的效果，用Visistty.setVisisty(View....)一直达到我想要的效果。用改变view的位置，平移到屏幕显示外面。并且带有动画效果来实现。貌似会更好点。直接看代码。一部分代码仿另一个开源项目基础上修改而来的。

主要原理是检查判定是否在滑动到屏幕的顶部或者底部，根据其顶部的话就，让我们的内容view偏移顶部高度为我们topview高度，否则view偏移量为0。并为其设置平移动画效果。

public class ScrollViewActivity extends Activity {    private PoppyViewHelper mPoppyViewHelper;    private LayoutInflater layoutInflater;    private NotifyingScrollView scrollView;    private View poppyview;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_scrollview);        layoutInflater=LayoutInflater.from(this);        scrollView=(NotifyingScrollView)findViewById(R.id.scrollView);        poppyview=layoutInflater.inflate(R.layout.poppyview, null);        mPoppyViewHelper = new PoppyViewHelper(this, PoppyViewPosition.TOP);        ViewGroup poppyView = mPoppyViewHelper.createPoppyViewOnScrollView(scrollView, poppyview);        poppyView.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Toast.makeText(ScrollViewActivity.this, "Click me!", Toast.LENGTH_SHORT).show();            }        });    }}public class PoppyViewHelper {    public enum PoppyViewPosition {        TOP, BOTTOM    };    private static final int SCROLL_TO_TOP = - 1;    private static final int SCROLL_TO_BOTTOM = 1;    private static final int SCROLL_DIRECTION_CHANGE_THRESHOLD = 5;    private Activity mActivity;    private LayoutInflater mLayoutInflater;    private View mPoppyView;    private int mScrollDirection = 0;    private int mPoppyViewHeight = - 1;    private PoppyViewPosition mPoppyViewPosition;    public PoppyViewHelper(Activity activity, PoppyViewPosition position) {        mActivity = activity;        mLayoutInflater = LayoutInflater.from(activity);        mPoppyViewPosition = position;    }    public PoppyViewHelper(Activity activity) {        this(activity, PoppyViewPosition.BOTTOM);    }    private ViewGroup viewGroup;    // for scrollview    private  NotifyingScrollView scrollView;    public ViewGroup createPoppyViewOnScrollView(NotifyingScrollView scrollViewId, View poppyViewResId) {         mPoppyView =poppyViewResId;         scrollView = scrollViewId;        initPoppyViewOnScrollView();        return viewGroup;    }    // for ListView    public View createPoppyViewOnListView(int listViewId, int poppyViewResId, OnScrollListener onScrollListener) {        final ListView listView = (ListView)mActivity.findViewById(listViewId);        if(listView.getHeaderViewsCount() != 0) {            throw new IllegalArgumentException("use createPoppyViewOnListView with headerResId parameter");        }        if(listView.getFooterViewsCount() != 0) {            throw new IllegalArgumentException("poppyview library doesn't support listview with footer");        }        mPoppyView = mLayoutInflater.inflate(poppyViewResId, null);        initPoppyViewOnListView(listView, onScrollListener);        return mPoppyView;    }    public View createPoppyViewOnListView(int listViewId, int poppyViewResId) {        return createPoppyViewOnListView(listViewId, poppyViewResId, null);    }    // common    private void setPoppyViewOnView(View view) {        LayoutParams lp = view.getLayoutParams();        ViewParent parent = view.getParent();        ViewGroup group = (ViewGroup)parent;        int index = group.indexOfChild(view);        final FrameLayout newContainer = new FrameLayout(mActivity);        group.removeView(view);        group.addView(newContainer, index, lp);        newContainer.addView(view);        final FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);        layoutParams.gravity = mPoppyViewPosition == PoppyViewPosition.BOTTOM ? Gravity.BOTTOM : Gravity.TOP;        newContainer.addView(mPoppyView, layoutParams);        group.invalidate();        viewGroup=group;    }    private boolean isjixu=false;    private void onScrollPositionChanged(int oldScrollPosition, int newScrollPosition) {        int newScrollDirection;        System.out.println(oldScrollPosition + " ->" + newScrollPosition);        if(newScrollPosition < oldScrollPosition) {            newScrollDirection = SCROLL_TO_TOP;            isjixu=true;            //gundong滚动dao到dingb顶部        } else {            newScrollDirection = SCROLL_TO_BOTTOM;            isjixu=false;        }        if(newScrollDirection != mScrollDirection) {            mScrollDirection = newScrollDirection;            translateYPoppyView();        }    }    private     int translationY = 0;    private boolean isdingbu=false;    private void translateYPoppyView() {        mPoppyView.post(new Runnable() {            @Override            public void run() {                if(mPoppyViewHeight <= 0) {                    mPoppyViewHeight = mPoppyView.getHeight();                }                switch (mPoppyViewPosition) {                case BOTTOM:                    translationY = mScrollDirection == SCROLL_TO_TOP ? 0 : mPoppyViewHeight;                    break;                case TOP:                    translationY = mScrollDirection == SCROLL_TO_TOP ?  0:  -mPoppyViewHeight;                    isdingbu=true;                    break;                }                ViewPropertyAnimator.animate(mPoppyView).setDuration(300).translationY(translationY);            }        });        if(isdingbu){            scrollView.post(new Runnable() {                @Override                public void run() {                    如果为顶部显示就让view平移Mpoppyviewhiegh高度                    ViewPropertyAnimator.animate(scrollView).setDuration(300).translationY(mPoppyViewHeight);                    isdingbu=false;                }            });        }else{            scrollView.post(new Runnable() {                @Override                public void run() {                    不然就让他显示在屏幕顶部                    ViewPropertyAnimator.animate(scrollView).setDuration(300).translationY(0);                }            });        }    }    // for ScrollView    private void initPoppyViewOnScrollView() {        setPoppyViewOnView(scrollView);        scrollView.setOnScrollChangedListener(new NotifyingScrollView.OnScrollChangedListener() {            int mScrollPosition;            public void onScrollChanged(ScrollView who, int l, int t, int oldl, int oldt) {                if(Math.abs(t - mScrollPosition) >= SCROLL_DIRECTION_CHANGE_THRESHOLD) {                    onScrollPositionChanged(mScrollPosition, t);                }                mScrollPosition = t;            }        });    }    // for ListView    private void initPoppyViewOnListView(ListView listView, final OnScrollListener onScrollListener) {        setPoppyViewOnView(listView);        listView.setOnScrollListener(new OnScrollListener() {            int mScrollPosition;            @Override            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {                if(onScrollListener != null) {                    onScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);                }                View topChild = view.getChildAt(0);                int newScrollPosition = 0;                if(topChild == null) {                    newScrollPosition = 0;                } else {                    newScrollPosition = - topChild.getTop() + view.getFirstVisiblePosition() * topChild.getHeight();                }                if(Math.abs(newScrollPosition - mScrollPosition) >= SCROLL_DIRECTION_CHANGE_THRESHOLD) {                    onScrollPositionChanged(mScrollPosition, newScrollPosition);                }                mScrollPosition = newScrollPosition;            }            @Override            public void onScrollStateChanged(AbsListView view, int scrollState) {                if(onScrollListener != null) {                    onScrollListener.onScrollStateChanged(view, scrollState);                }            }        });    }}