Question

我在LinearLayout中安装了View和RecyclerView。我想要实现的是这样的：

https://material.google.com/patterns/scrolling-techniques.html#scrolling-techniques-behavior

基本上，当我向上滚动RecyclerView时，View会折叠。如果我向下滚动RecyclerView，它会扩展。

我尝试了各种方法，但如果手指在滚动位置周围抖动，则动画会断断续续。如果手指在一个方向上进行有意的滚动运动，它只会动画很好。我该如何正确地做到这一点？

Answer 1

您必须将协调器布局与CollapsingToolbarLayout

一起使用

<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false">

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar_layout"
    android:layout_width="match_parent"
    android:layout_height="210dp"
    android:stateListAnimator="@animator/appbar_always_elevated" //I put this here because I want to have shadow when is open, but you have to create the xml file.
    android:background="@color/WHITE">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:collapsedTitleTextAppearance="@style/TextAppearance.AppCompat.Widget.ActionBar.Title.Inverse"
        app:expandedTitleMarginStart="72dp"
        app:expandedTitleTextAppearance="@style/TextAppearance.AppCompat.Widget.ActionBar.Title.Inverse"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"> //HERE you should take a look what you want your collapse bar do.

        <Here you put the content for you collapse bar, like a ImageView>

        <android.support.v7.widget.Toolbar //This is the size of your fixed bar when you collapse, even here you can put a back button, for example
            android:id="@+id/app_bar"
            android:layout_width="match_parent"
            android:layout_height="40dp"
            app:layout_collapseMode="pin" />
    </android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>

<android.support.v4.widget.SwipeRefreshLayout
    android:id="@+id/main_home_list_swipe"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" >

    <android.support.v7.widget.RecyclerView
        android:id="@+id/main_home_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</android.support.design.widget.CoordinatorLayout >

Obs：如果您放入xml文件，注释会出错。提议，所以你会记得读哈哈哈

Answer 2

试试这个： - 我也想在自定义视图上使用这种动画，我已经通过这种方式实现了它。

public class TestActivity extends AppCompatActivity {
    private static final int HIDE_THRESHOLD = 20;
    //this is you custom layout it is any thing.
    LinearLayout customLayout;
    private int scrolledDistance = 0;
    private boolean controlsVisible = true;
    private RecyclerView recyclerView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.your_layout);

        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
            }

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                if (scrolledDistance > HIDE_THRESHOLD && controlsVisible) {
                    hideViews();
                    controlsVisible = false;
                    scrolledDistance = 0;
                } else if (scrolledDistance < -HIDE_THRESHOLD && !controlsVisible) {
                    showViews();
                    controlsVisible = true;
                    scrolledDistance = 0;
                }
            }
        });
    }

    private void hideViews() {
        customLayout.animate().translationY(-customLayout.getHeight()).setInterpolator(new AccelerateInterpolator(2));
    }

    private void showViews() {
        customLayout.animate().translationY(0).setInterpolator(new DecelerateInterpolator(2));
    }
}

修改 - 1 for ScrollView试试这个监听器

scrollView.getViewTreeObserver().addOnScrollChangedListener(new ViewTreeObserver.OnScrollChangedListener() {
            @Override
            public void onScrollChanged() {
                if (scrolledDistance > HIDE_THRESHOLD && controlsVisible) {
                    hideViews();
                    controlsVisible = false;
                    scrolledDistance = 0;
                } else if (scrolledDistance < -HIDE_THRESHOLD && !controlsVisible) {
                    showViews();
                    controlsVisible = true;
                    scrolledDistance = 0;
                }
            }
        });

希望它也可以帮助你...

Answer 3

要实现工具栏的平滑展开和折叠，您可以应用翻译动画或将CoordinatorLayout与AppBarLayout和工具栏一起使用。

动画：首先，您必须检测向上滚动并向下滚动RecyclerView。为此，您可以在RecyclerView上设置“setOnScrollListener”。一旦你向上滚动并向下滚动，只需应用动画。

<强>代码：

rvHomeList.setOnScrollListener(new RecyclerView.OnScrollListener() {

            int verticalOffset;

            boolean scrollingUp;

            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                if (newState == RecyclerView.SCROLL_STATE_IDLE) {
                    if (scrollingUp) {
                        Log.e("onScrollStateChanged", "UP");
                        if (verticalOffset > llTop.getHeight()) {
                            toolbarAnimateHide();
                        }
                    } else {
                        Log.e("onScrollStateChanged", "down");
                        if (llTop.getTranslationY() < llTop.getHeight() * -0.6 && verticalOffset > llTop.getHeight()) {
                            toolbarAnimateHide();
                        } else {
                            toolbarAnimateShow(verticalOffset);
                        }
                    }
                }
            }

            @Override
            public final void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                verticalOffset += dy;
                scrollingUp = dy > 0;
                int toolbarYOffset = (int) (dy - llTop.getTranslationY());
                llTop.animate().cancel();
                if (scrollingUp) {
                    Log.e("onScrolled", "UP");
                    if (toolbarYOffset < llTop.getHeight()) {
                        llTop.setTranslationY(-toolbarYOffset);
                    } else {
                        llTop.setTranslationY(-llTop.getHeight());
                    }
                } else {
                    Log.e("onScrolled", "down");
                    if (toolbarYOffset < 0) {
                        llTop.setTranslationY(0);
                    } else {
                        llTop.setTranslationY(-toolbarYOffset);
                    }
                }
            }
        });

动画方法：

private void toolbarAnimateShow(final int verticalOffset) {
        if (!isShowing) {
            isShowing = true;
            llTop.animate()
                    .translationY(0)
                    .setInterpolator(new LinearInterpolator())
                    .setDuration(180)
                    .setListener(new AnimatorListenerAdapter() {
                        @Override
                        public void onAnimationStart(Animator animation) {
                            llTop.setVisibility(View.VISIBLE);
                            isShowing = false;
                        }
                    });
        }
    }

    private void toolbarAnimateHide() {
        if (!isHidding) {
            isHidding = true;
            llTop.animate()
                    .translationY(-llTop.getHeight())
                    .setInterpolator(new LinearInterpolator())
                    .setDuration(180)
                    .setListener(new AnimatorListenerAdapter() {
                        @Override
                        public void onAnimationEnd(Animator animation) {
                            llTop.setVisibility(View.GONE);
                            isHidding = false;
                        }
                    });
        }
    }

使用AppBarLayout和工具栏的CoordinatorLayout ：通过使用带有appBarLayout和工具栏的coordinatorLayout，并设置属性app中使用的滚动标记：layout_scrollFlags以实现滚动效果。必须启用它才能使任何滚动效果生效。此标志必须与enterAlways，enterAlwaysCollapsed，exitUntilCollapsed或snap一起启用。

enterAlways：向上滚动时视图将变为可见。当从列表底部滚动并希望在滚动时立即公开工具栏时，此标志非常有用。
enterAlwaysCollapsed：通常情况下，只使用enterAlways时，工具栏会在您向下滚动时继续展开。如果声明了enterAlways并指定了minHeight，您还可以指定enterAlwaysCollapsed。使用此设置时，您的视图将仅显示在此最小高度。只有当滚动到达顶部时，视图才会扩展到其全高
exitUntilCollapsed：当设置滚动标记时，向下滚动通常会导致整个内容移动。通过指定minHeight和exitUntilCollapsed，工具栏的最小高度将在其余部分之前达到内容开始滚动并退出屏幕
snap：使用此选项将确定仅在部分缩小视图时要执行的操作。如果滚动结束并且视图大小已减小到原始视图的小于50％，则此视图将恢复为其原始大小。如果尺寸大于其尺寸的50％，它将完全消失。

<强>代码：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/llBase"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white"
    android:orientation="vertical">

    <android.support.design.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/appbarContainer"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="@dimen/_40sdp"
                android:gravity="center"
                android:theme="@style/ThemeOverlay.AppCompat.Light"
                app:layout_scrollFlags="scroll|enterAlways">

                <include
                    layout="@layout/top_bar"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content" />
            </android.support.v7.widget.Toolbar>
        </android.support.design.widget.AppBarLayout>

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

            <RelativeLayout
                android:id="@+id/rlMain"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1"/>

        </RelativeLayout>
    </android.support.design.widget.CoordinatorLayout>

</LinearLayout>

Answer 4

您需要使用 CoordinatorLayout 来实现您的目标。您可以在此tutorial中找到所有需要的信息。

如何根据滚动方向折叠/展开视图？

4 个答案: