Android 同步滚动多个RecyclerViews

我有一个ViewPager，每页显示一个片段。此片段包含RecyclerView中的项目列表。项目列表的大小始终相同，项目视图的高度也相同。滚动其中一个RecyclerViews时，我希望其他RecyclerViews在相同的时间和相同的距离滚动。如何同步RecyclerViews的滚动？

在寻呼机适配器中创建变量，该变量将负责为其页面保存当前的

scrollY

位置，并且每当您的

getItem（position）

调用update

ListView

位置时，请查看中的

CacheFragmentStatePagerAdapter

---

我相信了解它的工作原理对您很重要，因此我将解释我设计解决方案所遵循的整个过程。请注意，此示例仅适用于两个RecyclerViews，但使用更多的RecyclerViews进行此操作与使用RecyclerViews数组一样简单

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv0"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        app:layout_constraintTop_toTopOf="parent"
        />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv1"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        android:layout_marginTop="5dp"
        app:layout_constraintTop_toBottomOf="@id/rv0"
        />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv2"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        android:layout_marginTop="5dp"
        app:layout_constraintTop_toBottomOf="@id/rv1"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

想到的第一个选项是在两个ScrollView上监听滚动更改，当其中一个滚动时，在另一个上使用。不幸的是，以编程方式滚动也会触发侦听器，因此最终会进入循环

为了解决这个问题，您需要设置一个OnItemTouchListener，在触摸RecyclerView时添加适当的ScrollListener，并在滚动停止时将其删除。这几乎完美无瑕，但如果您在一个长的RecyclerView中快速抛出，然后在完成之前再次滚动，则只会转移第一个滚动

要解决此问题，您需要确保仅在RecyclerView空闲时添加OnScrollListener

让我们看看来源：

    public class SelfRemovingOnScrollListener extends RecyclerView.OnScrollListener {

    @Override
    public final void onScrollStateChanged(@NonNull final RecyclerView recyclerView, final int newState) {
        super.onScrollStateChanged(recyclerView, newState);
        if (newState == RecyclerView.SCROLL_STATE_IDLE) {
            recyclerView.removeOnScrollListener(this);
        }
    }
}

这是需要从中扩展OnScrollListeners的类。这可确保在需要时将其移除

然后我有两个侦听器，每个RecyclerView一个：

private final RecyclerView.OnScrollListener mLeftOSL = new SelfRemovingOnScrollListener() {
    @Override
    public void onScrolled(@NonNull final RecyclerView recyclerView, final int dx, final int dy) {
        super.onScrolled(recyclerView, dx, dy);
        mRightRecyclerView.scrollBy(dx, dy);
    }
}, mRightOSL = new SelfRemovingOnScrollListener() {

    @Override
    public void onScrolled(@NonNull final RecyclerView recyclerView, final int dx, final int dy) {
        super.onScrolled(recyclerView, dx, dy);
        mLeftRecyclerView.scrollBy(dx, dy);
    }
};

然后在初始化时，您可以设置OnItemTouchListeners。最好为整个视图设置一个侦听器，但RecyclerView不支持这一点。OnItemTouchListeners不会带来任何问题：

    mLeftRecyclerView.addOnItemTouchListener(new RecyclerView.OnItemTouchListener() {

        private int mLastY;

        @Override
        public boolean onInterceptTouchEvent(@NonNull final RecyclerView rv, @NonNull final
        MotionEvent e) {
            Log.d("debug", "LEFT: onInterceptTouchEvent");

            final Boolean ret = rv.getScrollState() != RecyclerView.SCROLL_STATE_IDLE;
            if (!ret) {
                onTouchEvent(rv, e);
            }
            return Boolean.FALSE;
        }

        @Override
        public void onTouchEvent(@NonNull final RecyclerView rv, @NonNull final MotionEvent e) {
            Log.d("debug", "LEFT: onTouchEvent");

            final int action;
            if ((action = e.getAction()) == MotionEvent.ACTION_DOWN && mRightRecyclerView
                    .getScrollState() == RecyclerView.SCROLL_STATE_IDLE) {
                mLastY = rv.getScrollY();
                rv.addOnScrollListener(mLeftOSL);
            }
            else {
                if (action == MotionEvent.ACTION_UP && rv.getScrollY() == mLastY) {
                    rv.removeOnScrollListener(mLeftOSL);
                }
            }
        }

        @Override
        public void onRequestDisallowInterceptTouchEvent(final boolean disallowIntercept) {
            Log.d("debug", "LEFT: onRequestDisallowInterceptTouchEvent");
        }
    });

    mRightRecyclerView.addOnItemTouchListener(new RecyclerView.OnItemTouchListener() {

        private int mLastY;

        @Override
        public boolean onInterceptTouchEvent(@NonNull final RecyclerView rv, @NonNull final
        MotionEvent e) {
            Log.d("debug", "RIGHT: onInterceptTouchEvent");

            final Boolean ret = rv.getScrollState() != RecyclerView.SCROLL_STATE_IDLE;
            if (!ret) {
                onTouchEvent(rv, e);
            }
            return Boolean.FALSE;
        }

        @Override
        public void onTouchEvent(@NonNull final RecyclerView rv, @NonNull final MotionEvent e) {
            Log.d("debug", "RIGHT: onTouchEvent");

            final int action;
            if ((action = e.getAction()) == MotionEvent.ACTION_DOWN && mLeftRecyclerView
                    .getScrollState
                            () == RecyclerView.SCROLL_STATE_IDLE) {
                mLastY = rv.getScrollY();
                rv.addOnScrollListener(mRightOSL);
            }
            else {
                if (action == MotionEvent.ACTION_UP && rv.getScrollY() == mLastY) {
                    rv.removeOnScrollListener(mRightOSL);
                }
            }
        }

        @Override
        public void onRequestDisallowInterceptTouchEvent(final boolean disallowIntercept) {
            Log.d("debug", "RIGHT: onRequestDisallowInterceptTouchEvent");
        }
    });
}

还要注意，在我的特殊情况下，RecyclerViews不是第一个接收触摸事件的，所以我需要拦截它。如果不是这样，您可以（应该）将onInterceptTouchEvent（…）中的代码合并到onTouchEvent（…）

最后，如果您的用户试图同时滚动两个RecyclerViews，这将导致崩溃。这里最好的解决方案是在包含RecyclerViews的直接父级中设置

android:splitMotionEvents=“false”

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv0"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        app:layout_constraintTop_toTopOf="parent"
        />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv1"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        android:layout_marginTop="5dp"
        app:layout_constraintTop_toBottomOf="@id/rv0"
        />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv2"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        android:layout_marginTop="5dp"
        app:layout_constraintTop_toBottomOf="@id/rv1"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

---

您可以看到此代码的示例。

我想我已经找到了一个非常简单的答案

正如Jorge Antonio Díaz Benito所说，“我想到的第一个选项是在两个ScrollView上监听滚动更改，当其中一个滚动时，在另一个滚动上使用scrollBy（int x，int y）。不幸的是，编程滚动也会触发侦听器，因此最终会进入循环。”

所以你需要解决这个问题。如果你只是跟踪谁在滚动，他们就不会循环

解决方案

public class SelfScrolListener extends RecyclerView.OnScrollListener {
    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
        if (newState == RecyclerView.SCROLL_STATE_IDLE) {
            viewIsScrolling = -1;
        }
    }
}

这是您的自定义OnScrollListener，用于检查scrollState是否空闲。这是真的吗->没有人滚动。因此，`int viewscolling=-1

现在需要检测是否可以滚动。 代码如下：

int viewIsScrolling = 1;
boolean firstIsTouched = false;
boolean secondIsTouched = false;
SelfScrolListener firstOSL= new SelfScrolListener() {
    @Override
    public void onScrolled(@NonNull final RecyclerView recyclerView, final int dx, final int dy) {
        super.onScrolled(recyclerView, dx, dy);

        if (firstIsTouched) {
             if (viewIsScrolling == -1) {
                 viewIsScrolling = 0;
             }
             if (viewIsScrolling == 0) {
                 secondRecyclerView.scrollBy(dx, dy);
             }
        }
    }
};
SelfScrolListener secondOSL= new SelfScrolListener() {
    @Override
    public void onScrolled(@NonNull final RecyclerView recyclerView, final int dx, final int dy) {
        super.onScrolled(recyclerView, dx, dy);
        if(secondIsTouched){
             if (viewIsScrolling == -1) {
                 viewIsScrolling = 1;
             }
             if (viewIsScrolling == 1) {
                 firstRecyclerView.scrollBy(dx, dy);
             }
        }
    }
};
firstRecyclerView.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        firstIsTouched= true;
        return false;
    }
});
secondRecyclerView.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        secondIsTouched= true;
        return false;
    }
});
firstRecyclerView.addOnScrollListener(firstOSL);
secondRecyclerView.addOnScrollListener(secondOSL);

---

viewscrolling=一个全局整数，并在开头设置为-1；无人滚动的状态。您可以根据需要为任意多个RecycleView添加广告。

这是我的解决方案。代码越少越好

lvDetail和lvDetail2是要保持同步的RecyclerViews

    final RecyclerView.OnScrollListener[] scrollListeners = new RecyclerView.OnScrollListener[2];
    scrollListeners[0] = new RecyclerView.OnScrollListener( )
    {
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy)
        {
            super.onScrolled(recyclerView, dx, dy);
            lvDetail2.removeOnScrollListener(scrollListeners[1]);
            lvDetail2.scrollBy(dx, dy);
            lvDetail2.addOnScrollListener(scrollListeners[1]);
        }
    };
    scrollListeners[1] = new RecyclerView.OnScrollListener( )
    {
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy)
        {
            super.onScrolled(recyclerView, dx, dy);
            lvDetail.removeOnScrollListener(scrollListeners[0]);
            lvDetail.scrollBy(dx, dy);
            lvDetail.addOnScrollListener(scrollListeners[0]);
        }
    };
    lvDetail.addOnScrollListener(scrollListeners[0]);
    lvDetail2.addOnScrollListener(scrollListeners[1]);

---

首先考虑使用<代码> NestStdScVIEW 作为<代码> RealReVIEW < /代码>的父级。这可能需要一些额外的调整，但总体思路是相同的：

<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</android.support.v4.widget.NestedScrollView>

召唤

享受

公共类SyncScrollActivity扩展了AppCompatActivity{
私人名单回收商；
私有布尔值isprogrammalyscrolling=false；
私有void addSyncListeners（）{
用于（RecyclerView RecyclerView:syncRecyclers）{
addOnScrollListener（新的SyncOnScrollListener（））；
}
}
私有类SyncOnScrollListener扩展了RecyclerView.OnScrollListener{
@凌驾
已克隆的公共void（@NonNull RecyclerView RecyclerView，int-dx，int-dy）{
如果（！程序化CROLING）{
isprogrammalycrolling=true；
scrollAll（循环视图、dx、dy）；
isprogrammalycrolling=假；
}
}
}
私有void scrollAll（RecyclerView exceptRecycler、int dx、int dy）{
用于（RecyclerView RecyclerView:syncRecyclers）{
如果（！recyclerView.equals（exceptRecycler））{
循环视图滚动比（dx，dy）；
}
}
}
}

kotlin版本，这一款不支持fling（目前）

类滚动同步器{
val boundRecyclerViews:ArrayList=ArrayList（）
变量垂直偏移=0
private val scrollListener=object:RecyclerView.OnScrollListener（）{
覆盖已克隆的乐趣（recyclerView:recyclerView，dx:Int，dy:Int）{
super.onScrolled（回收视图、dx、dy）
//每隔一个rv滚动到相同位置
boundRecyclerViews.filter{it！=recyclerView}.forEach{targetView->
targetView.removeOnScrollListener（此）
targetView.scrollBy（dx，dy）
targetView.addOnScrollListener（此）
}
}
覆盖CrollStateChanged（recyclerView:recyclerView，newState:Int）{
super.onScrollStateChanged（recyclerView、newState）
if（newState==RecyclerView.SCROLL\u STATE\u IDLE）{
verticalOffset=recyclerView.computeVerticalScrollOff
public class SyncScrollActivity extends AppCompatActivity {
    private List<RecyclerView> syncRecyclers;
    private boolean isProgrammaticallyScrolling = false;


    private void addSyncListeners() {
        for (RecyclerView recyclerView : syncRecyclers) {
            recyclerView.addOnScrollListener(new SyncOnScrollListener());
        }
    }

    private class SyncOnScrollListener extends RecyclerView.OnScrollListener {
        @Override
        public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
            if (!isProgrammaticallyScrolling) {
                isProgrammaticallyScrolling = true;
                scrollAll(recyclerView, dx, dy);
                isProgrammaticallyScrolling = false;
            }
        }
    }

    private void scrollAll(RecyclerView exceptRecycler, int dx, int dy) {
        for (RecyclerView recyclerView : syncRecyclers) {
            if (!recyclerView.equals(exceptRecycler)) {
                recyclerView.scrollBy(dx, dy);
            }
        }
    }
}

class ScrollSynchronizer {
    val boundRecyclerViews: ArrayList<RecyclerView> = ArrayList()
    var verticalOffset = 0

    private val scrollListener = object: RecyclerView.OnScrollListener() {
        override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
            super.onScrolled(recyclerView, dx, dy)
            // scroll every other rv to the same position
            boundRecyclerViews.filter { it != recyclerView }.forEach { targetView ->
                targetView.removeOnScrollListener(this)
                targetView.scrollBy(dx, dy)
                targetView.addOnScrollListener(this)
            }
        }

        override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
            super.onScrollStateChanged(recyclerView, newState)
            if (newState == RecyclerView.SCROLL_STATE_IDLE) {
                verticalOffset = recyclerView.computeVerticalScrollOffset()
            }
        }
    }

    fun add(view: RecyclerView) {
        with (view) {
            if (boundRecyclerViews.contains(view)) {
                removeOnScrollListener(scrollListener)
                boundRecyclerViews.remove(this)
            }
            addOnScrollListener(scrollListener)
            boundRecyclerViews.add(this)
        }
    }

    fun scrollToLastOffset(rv: RecyclerView) {
        rv.removeOnScrollListener(scrollListener)
        val currentOffset = rv.computeVerticalScrollOffset()
        if (currentOffset != verticalOffset) {
            rv.scrollBy(0, verticalOffset - currentOffset)
        }
        rv.addOnScrollListener(scrollListener)
    }

    fun disable() = boundRecyclerViews.forEach { it.removeOnScrollListener(scrollListener) }

    fun enable() = boundRecyclerViews.forEach { it.addOnScrollListener(scrollListener) }

    fun addAll(recyclerViews: List<RecyclerView>) = recyclerViews.forEach { add(it) }
}

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv0"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        app:layout_constraintTop_toTopOf="parent"
        />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv1"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        android:layout_marginTop="5dp"
        app:layout_constraintTop_toBottomOf="@id/rv0"
        />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv2"
        android:layout_width="match_parent"
        android:layout_height="@dimen/itemSize"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:orientation="horizontal"
        android:layout_marginTop="5dp"
        app:layout_constraintTop_toBottomOf="@id/rv1"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

 val scrollListener = object : RecyclerView.OnScrollListener() {
                override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                    super.onScrolled(recyclerView, dx, dy)
                    horizontalScroll(this, recyclerView, dx)
                }
            }



fun horizontalScroll(
            scrollListener: RecyclerView.OnScrollListener,
            currentRecycler: RecyclerView,
            dx: Int
        ) {
            for (i in 0..parentRecyclerView.childCount) {
                val childRecyclerView =
                    parentRecyclerView.getChildAt(i)?.findViewById<RecyclerView>(R.id.recyclerView)
                if (currentRecycler != childRecyclerView) {
                    childRecyclerView?.removeOnScrollListener(scrollListener)
                    childRecyclerView?.scrollBy(dx, 0)
                    childRecyclerView?.addOnScrollListener(scrollListener)
                }
            }
        }