我有一个布局(代码在底部),其中包含顶部的CollapsingToolBarLayout和底部的NestedScrollView。当我向上滚动时,折叠工具栏将开始折叠,然后滚动视图将首先随着折叠工具栏向上滚动,然后进入折叠工具栏后面。我想在折叠工具栏中添加一些动画(向上滚动时图像向左滑动,向下滚动时图像向右滑动)。问题是:有时候,当我向上滚动时,图像不会向左滑动。当它向左滑动时,如果我向下滚动,则不会向右滑动。我通过AppBarLayout的onOffsetChanged和NestedScrollView的OnTouchListener触发这些动画。
// People image slide left when user scrolls up on the scroll view
mScrollView.setOnTouchListener(scrollViewTouchListener);
// People image slide back when app bar is almost expanded
mAppBar.addOnOffsetChangedListener(appBarOffsetChangedListener);
// OnOffsetChangedListener for the AppBarLayout
private AppBarLayout.OnOffsetChangedListener appBarOffsetChangedListener = new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int offset) {
// If the app bar is almost expanded and people image slided left, make it slide back
if ((offset > -20 || offset == 0) && mPeopleSlidedLeft) {
mPeopleImage.animate().setDuration(animationTime)
.translationX(originalPeoplePosition[0]);
mPeopleSlidedLeft = false;
}
}
};
// Touch listener for the scroll view
private View.OnTouchListener scrollViewTouchListener = new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
float y = event.getY();
if (event.getAction() == MotionEvent.ACTION_MOVE) {
float dy = y - mPreviousY;
// if user scrolls up and people image hasn't slided left,
if (dy < -1 && mPeopleSlidedLeft == false) {
DisplayMetrics dm = new DisplayMetrics();
getActivity().getWindowManager().getDefaultDisplay().getMetrics(dm);
int xDest = dm.widthPixels / 2;
xDest += mPeopleImage.getMeasuredWidth() / 2;
mPeopleImage.animate().setDuration(animationTime)
.translationX(originalPeoplePosition[0] - xDest);
}
}
mPeopleSlidedLeft = true;
mPreviousY = y;
return false;
}
};
请注意,ScrollView的setOnScrollChangeListener无法工作,因为当toolbar折叠时不会触发它。
以下是该布局的简化版本:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:elevation="0dp">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="@dimen/collapsing_toolbar_margin"
android:fitsSystemWindows="true"
android:minHeight="120dp"
app:contentScrim="?attr/colorPrimary"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<LinearLayout
android:id="@+id/backdrop"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white"
android:fitsSystemWindows="true"
android:orientation="vertical"
app:layout_collapseMode="parallax">
</LinearLayout>
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="@dimen/toolbar_height"
android:layout_gravity="center_horizontal"
app:contentInsetEnd="16dp"
app:contentInsetStart="16dp"
app:elevation="0dp"
app:layout_collapseMode="pin"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light">
</android.support.v7.widget.Toolbar>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true"
android:background="@color/white"
android:orientation="vertical"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
<android.support.v4.widget.NestedScrollView
android:id="@+id/scroll_view"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
</android.support.v4.widget.NestedScrollView>
</LinearLayout>
<include
layout="@layout/notification"
android:layout_width="match_parent"
android:layout_height="@dimen/active_inactive_time_height"
android:layout_gravity="bottom"
app:layout_anchorGravity="bottom|right"
android:layout_marginBottom="@dimen/bottom_navigation_bar_offset" />
</android.support.design.widget.CoordinatorLayout>
有人可以帮忙看一下吗?我会非常感激!
Behavior
,可以查看android.support.design.widget.FloatingActionButton.Behavior
的示例,您也可以阅读这些文章1和2。 - M. Reza Nasirloo