带片段的 AppBarLayout

Question

所以，情况是这样的：

我需要在我的主 activity 中实现 AppBar 滚动行为，但是，我的片段中已经有 CoordinatorLayout 和 AppBarLayout 具有相同的滚动行为。

这是两种布局的 xml：

activity_main:

<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:background="#EBEDEC">

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ImageView
            android:id="@+id/toolbar_open_nav"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_centerVertical="true"
            android:src="@drawable/filter_icon" />

        <RelativeLayout
            android:id="@+id/main_activity_images_relative"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <ImageView
                android:id="@+id/toolbar_fencity_image"
                android:layout_width="200dp"
                android:layout_height="match_parent"
                android:layout_centerInParent="true"
                android:layout_margin="@dimen/layout_padding"
                android:src="@drawable/toolbarimg"
                android:visibility="gone" />


        </RelativeLayout>


    </RelativeLayout>


</android.support.v7.widget.Toolbar>

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <FrameLayout
            android:id="@+id/main_content"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:background="@android:color/transparent" />

        <com.bitage.carlo.fencity.ui.view.BottomMenuView
            android:id="@+id/bottom_menu"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize" />


    </LinearLayout>


</RelativeLayout>

和片段xml:

  <?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="?attr/actionBarSize"
    android:orientation="vertical">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/novita_app_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <RelativeLayout
            android:id="@+id/novita_search_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/background"
            app:layout_scrollFlags="scroll|enterAlways|snap">

            <EditText
                android:id="@+id/search_edit"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="@dimen/layout_padding"
                android:background="@null"
                android:hint="@string/search"
                android:imeOptions="actionDone"
                android:paddingEnd="@dimen/layout_padding"
                android:paddingLeft="@dimen/padding_start"
                android:paddingRight="@dimen/layout_padding"
                android:paddingStart="@dimen/padding_start"
                android:singleLine="true" />

            <ImageView
                android:id="@+id/search_image"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginLeft="@dimen/layout_padding"
                android:layout_marginStart="@dimen/layout_padding"
                android:src="@drawable/ic_search" />

        </RelativeLayout>

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


    <RelativeLayout
        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/places_recycler_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:background="@android:color/transparent"
            android:src="@drawable/nav_shadow" />

    </RelativeLayout>


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

现在，我需要它尽可能保持不变，只是以某种方式仅在此片段中的工具栏上添加滚动行为 app:layout_scrollFlags="scroll|enterAlways|snap"，而从片段中搜索仍然具有相同的行为。

我怎样才能做到这一点？

Answer 1

所以，你可以做下一步：

在您的片段 class 中，您有 recyclerview。现在，您要做的是将 recyclerView.addOnScrollListener(new YourScrollListenerClass(context, toolbar, coordinatorLayout));

Coordinator布局是fragment之一，请牢记。

现在，创建一个新的 class YourScrollListenerClass:

    public class YourScrollListenerClass extends RecyclerView.OnScrollListener {

        private Context mContext;
        private Toolbar mToolbar;
        private CoordinatorLayout mCoordinatorLayout;
        private int mToolbarHeight;
        private int mCoordinatorLayoutTopMargin;

    public YourScrollListenerClass(Context context, @Nullable Toolbar toolbar, @Nullable final CoordinatorLayout mCoordinatorLayout) {
            this.mContext = context;
            mToolbar = toolbar;
            this.mCoordinatorLayout = mCoordinatorLayout;
            if (mToolbar != null && mCoordinatorLayout != null) {
                mToolbar.post(new Runnable() {
                    @Override
                    public void run() {
                        mToolbarHeight = mToolbar.getHeight();
                    }
                });

                mCoordinatorLayout.post(new Runnable() {
                    @Override
                    public void run() {
                        mCoordinatorLayoutTopMargin = ((FrameLayout.LayoutParams) mCoordinatorLayout.getLayoutParams()).topMargin;
                    }
                });
            }
        }

    @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            if (recyclerView != null) {
    if (mToolbar != null) {
                float offset = mToolbar.getTranslationY() - dy;
                if (offset <= 0 && offset >= -(mToolbar.getHeight())) {
                    mToolbar.setTranslationY(mToolbar.getTranslationY() - dy);
                    FrameLayout.LayoutParams params1 = (FrameLayout.LayoutParams) mCoordinatorLayout.getLayoutParams();
                    params1.setMargins(0, params1.topMargin - dy, 0, 0);
                    mCoordinatorLayout.setLayoutParams(params1);                  
                }
            }
    }
    }

@Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
         if (RecyclerView.SCROLL_STATE_IDLE == newState) {           
            if(mToolbar != null) {
                if (Math.abs(mToolbar.getTranslationY()) <= mToolbar.getHeight() / 2) {
                    ObjectAnimator animator = ObjectAnimator.ofFloat(mToolbar, View.TRANSLATION_Y, mToolbar.getTranslationY(), 0);
                    animator.setDuration(300);
                    animator.start();
                    MarginAnimation animation = new MarginAnimation(mCoordinatorLayout, ((FrameLayout.LayoutParams) mCoordinatorLayout.getLayoutParams()).topMargin, mCoordinatorLayoutTopMargin);
                    mCoordinatorLayout.startAnimation(animation);
                } else {
                    ObjectAnimator animator = ObjectAnimator.ofFloat(mToolbar, View.TRANSLATION_Y, mToolbar.getTranslationY(), -mToolbarHeight);
                    animator.setDuration(300);
                    animator.start();
                    MarginAnimation animation = new MarginAnimation(mCoordinatorLayout, ((FrameLayout.LayoutParams) mCoordinatorLayout.getLayoutParams()).topMargin, 0);
                    mCoordinatorLayout.startAnimation(animation);
                }
            }
        }
    }

    }

并为边距动画创建新的Class

public class MarginAnimation extends Animation {

    private View mView;
    private float mToMargin;
    private float mFromMargin;
    private Context mContext;

    public MarginAnimation(View v, float fromTop, float toTop) {
        mFromMargin = fromTop;
        mToMargin = toTop;
        mView = v;
        setDuration(300);
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        float topMargin = (mToMargin - mFromMargin) * interpolatedTime + mFromMargin;
        Log.d("TopMargin", String.valueOf(topMargin));
        FrameLayout.LayoutParams p = (FrameLayout.LayoutParams) mView.getLayoutParams();
        p.setMargins(0, (int) topMargin, 0, 0);
        mView.setLayoutParams(p);
        mView.requestLayout();
    }

    @Override
    public void initialize(int width, int height, int parentWidth, int parentHeight) {
        super.initialize(width, height, parentWidth, parentHeight);
    }

    @Override
    public boolean willChangeBounds() {
        return true;
    }
}

希望这对您有所帮助...

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