2

我试图在向下滚动时隐藏文本视图并在向上滚动时显示它如果我有一个像 10 或 15 这样的项目但它工作正常但如果我有更少的项目它就不一样了

中recyclerview，我有展开/折叠功能，所以有时不一样

textview有时不隐藏/可见我不明白我将此行添加到我想在滚动时隐藏/显示的视图中

app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"

XML

<androidx.coordinatorlayout.widget.CoordinatorLayout
        android:id="@+id/lnMain"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@mipmap/bg"
        tools:context=".tab.history.view.HistoryFragment">

        <com.google.android.material.appbar.AppBarLayout
            android:id="@+id/mAppBarLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:elevation="0dp">

            <RelativeLayout
                android:id="@+id/lnActionBar"
                android:layout_width="match_parent"
                android:layout_height="?android:attr/actionBarSize"
                android:background="@color/colorPrimary">

                <TextView
                    android:id="@+id/tvtitle"
                    style="@style/fontMedium"
                    android:layout_width="wrap_content"
                    android:layout_height="?android:attr/actionBarSize"
                    android:layout_centerHorizontal="true"
                    android:gravity="center_vertical"
                    android:text="@string/beacon"
                    android:textColor="@color/white"
                    android:textSize="@dimen/header_font_size" />

            </RelativeLayout>

        </com.google.android.material.appbar.AppBarLayout>

       
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rvBeacon"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipToPadding="false"
        android:overScrollMode="never"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:paddingBottom="@dimen/_40sdp"
        android:scrollbars="none"
        android:visibility="visible"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        tools:itemCount="10"
        tools:listitem="@layout/raw_beacon" />

<TextView
            android:id="@+id/btnBack"
            style="@style/fontBold"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="@dimen/_10sdp"
            android:layout_marginBottom="@dimen/_20sdp"
            android:background="@drawable/background_button_yellow_20dp"
            android:contentDescription="@string/back_button"
            android:drawableStart="@drawable/ic_back"
            android:layout_gravity="bottom|center_horizontal"
            android:drawablePadding="@dimen/_5sdp"
            android:gravity="center"
            android:padding="@dimen/_10sdp"
            android:text="@string/back_to_search"
            android:textColor="@color/white"
            android:textSize="@dimen/button_font_size"
            android:visibility="@{!isScanning ? View.VISIBLE: View.GONE}"
            app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>

这是我到目前为止所做的，但不是每次都有效

注意：- 请不要我有一个recyclerview扩展 onclick 的项目，因此滚动和 textview 必须按照该项目行事

任何帮助都会受到高度评价

4

2 回答 2

1

我不知道为什么HideBottomViewOnScrollBehavior不适合你

app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"

可能是因为你有一个展开/折叠功能，因为你只有 recyclerview 在屏幕上，所以你也可以通过添加自定义 ScrollListener 来执行这个任务

MyRecyclerScroll 类

public abstract class MyRecyclerScroll extends RecyclerView.OnScrollListener {
    private static final float HIDE_THRESHOLD = 100;
    private static final float SHOW_THRESHOLD = 50;

    int scrollDist = 0;
    private boolean isVisible = true;

    //    We dont use this method because its action is called per pixel value change
    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);

        //  Check scrolled distance against the minimum
        if (isVisible && scrollDist > HIDE_THRESHOLD) {
            //  Hide fab & reset scrollDist
            hide();
            scrollDist = 0;
            isVisible = false;
        }
        //  -MINIMUM because scrolling up gives - dy values
        else if (!isVisible && scrollDist < -SHOW_THRESHOLD) {
            //  Show fab & reset scrollDist
            show();

            scrollDist = 0;
            isVisible = true;
        }

        //  Whether we scroll up or down, calculate scroll distance
        if ((isVisible && dy > 0) || (!isVisible && dy < 0)) {
            scrollDist += dy;
        }

    }


    public abstract void show();

    public abstract void hide();
}

活动/片段

binding.rvBeacon.addOnScrollListener(object : MyRecyclerScroll() {
            override fun show() {
                binding.btnBack.animate().translationY(0f).setInterpolator(DecelerateInterpolator(2f)).start()
            }

            override fun hide() {
                binding.btnBack.animate().translationY(binding.btnBack.getHeight() + 60f)
                    .setInterpolator(AccelerateInterpolator(2f)).start()
            }
        })

您可以根据需要更改动画、延迟和边距

有关更多详细信息，请参阅此博客

注意：如果您在滚动视图中的回收器视图将不起作用

于 2020-11-13T10:43:35.957 回答
1

如何进行自定义行为？

例如。

public class QuickReturnFooterBehavior extends CoordinatorLayout.Behavior<View> {

    private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
    private static final long ANIMATION_DURATION = 200;

    private int dyDirectionSum;
    private boolean isShowing;
    private boolean isHiding;
    private boolean isNeedOption = true;

    public boolean isNeedOption() {
        return isNeedOption;
    }

    public void setNeedOption(boolean needOption) {
        isNeedOption = needOption;
    }

    public QuickReturnFooterBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull View child, @NonNull View directTargetChild, @NonNull View target, int axes, int type) {
        return axes == ViewCompat.SCROLL_AXIS_VERTICAL;
    }

    @Override
    public void onNestedPreScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull View child, @NonNull View target, int dx, int dy, @NonNull int[] consumed, int type) {
        // scroll chhange up and down
        if (isNeedOption) {
            showView(child);
        } else {
            if (dy > 0 && dyDirectionSum < 0
                    || dy < 0 && dyDirectionSum > 0) {
                child.animate().cancel();
                dyDirectionSum = 0;
            }

            dyDirectionSum += dy;

            if (dyDirectionSum > child.getHeight()) {
                hideView(child);
            } else if (dyDirectionSum < -child.getHeight()) {
                showView(child);
            }

        }

    }

    private void hideView(final View view) {
        if (isHiding || view.getVisibility() != View.VISIBLE) {
            return;
        }

        ViewPropertyAnimator animator = view.animate()
                .translationY(view.getHeight())
                .setInterpolator(INTERPOLATOR)
                .setDuration(ANIMATION_DURATION);

        animator.setListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animator) {
                isHiding = true;
            }

            @Override
            public void onAnimationEnd(Animator animator) {
                isHiding = false;
                view.setVisibility(View.INVISIBLE);
            }

            @Override
            public void onAnimationCancel(Animator animator) {
                // show when cancle
                isHiding = false;
                showView(view);
            }

            @Override
            public void onAnimationRepeat(Animator animator) {
                // no-op
            }
        });

        animator.start();
    }

    private void showView(final View view) {
        if (isShowing || view.getVisibility() == View.VISIBLE) {
            return;
        }
        ViewPropertyAnimator animator = view.animate()
                .translationY(0)
                .setInterpolator(INTERPOLATOR)
                .setDuration(ANIMATION_DURATION);

        animator.setListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animator) {
                isShowing = true;
                view.setVisibility(View.VISIBLE);
            }

            @Override
            public void onAnimationEnd(Animator animator) {
                isShowing = false;
            }

            @Override
            public void onAnimationCancel(Animator animator) {
                // show when cancle
                isShowing = false;
                hideView(view);
            }

            @Override
            public void onAnimationRepeat(Animator animator) {
                // no-op
            }
        });

        animator.start();
    }
}

更新：检查可以滚动行为

child.canScrollVertically(1)  // "Top of list"
child.canScrollVertically(-1)  // "End of list"

**更新：添加 setter 和 getter **

private boolean isNeedOption = true;
于 2020-11-13T07:02:04.610 回答