blocks|key|4564407|text|当您调用setAdapter时，这不会立即在屏幕上对项目进行布局和定位(这需要一个布局过程)，因此当您调用scrollToPosition()调用时，它没有实际的元素可滚动到。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4564408|相反，您应该注册ViewTreeObserver.OnGlobalLayoutListener+(通过addOnGlobalLayoutListner()，它会将您的scrollToPosition()延迟到第一次布局遍历之后：|4564409|conversationView.getViewTreeObserver().addOnGlobalLayoutListener(new+ViewTreeObserver.OnGlobalLayoutListener()+{
++public+void+onGlobalLayout()+{
++++conversationView.scrollToPosition(GENERIC_MESSAGE_LIST.size();
++++//+Unregister+the+listener+to+only+call+scrollToPosition+once
++++conversationView.getViewTreeObserver().removeGlobalOnLayoutListener(this);

++++//+Use+vto.removeOnGlobalLayoutListener(this)+on+API16%2B+devices+as+
++++//+removeGlobalOnLayoutListener+is+deprecated.
++++//+They+do+the+same+thing,+just+a+rename+so+your+choice.
++}
});|code-block|syntax|javascript|4564410|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/view/ViewTreeObserver.OnGlobalLayoutListener.html|1|http://developer.android.com/reference/android/view/ViewTreeObserver.html#addOnGlobalLayoutListener(android.view.ViewTreeObserver.OnGlobalLayoutListener%2529)%2520from%2520a%2520%2560ViewTreeObserver%2560%2520created%2520by%2520%2560conversationView.getViewTreeObserver()%2560^0|4|A|1H|I|0|2B|I|8|13|0|1F|Q|1|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@$9|14|A|15|1|16]|$9|17|A|18|1|19]]|E|$]]|$1|H|3|I|5|J|7|1A|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|1B|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]|U|$5|P|Q|R|E|$S|V]]]]

When you call <code>setAdapter</code>, that does not immediately lay out and position items on the screen (that takes a single layout pass) hence your <code>scrollToPosition()</code> call has no actual elements to scroll to when you call it.

Instead, you should register a <a href="http://developer.android.com/reference/android/view/ViewTreeObserver.OnGlobalLayoutListener.html" rel="nofollow noreferrer">ViewTreeObserver.OnGlobalLayoutListener</a> (via <a href="http://developer.android.com/reference/android/view/ViewTreeObserver.html#addOnGlobalLayoutListener(android.view.ViewTreeObserver.OnGlobalLayoutListener)" rel="nofollow noreferrer">addOnGlobalLayoutListner()</a> from a <code>ViewTreeObserver</code> created by <code>conversationView.getViewTreeObserver()</code>) which delays your <code>scrollToPosition()</code> until after the first layout pass:

<pre><code>conversationView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
 public void onGlobalLayout() {
 conversationView.scrollToPosition(GENERIC_MESSAGE_LIST.size();
 // Unregister the listener to only call scrollToPosition once
 conversationView.getViewTreeObserver().removeGlobalOnLayoutListener(this);

 // Use vto.removeOnGlobalLayoutListener(this) on API16+ devices as 
 // removeGlobalOnLayoutListener is deprecated.
 // They do the same thing, just a rename so your choice.
 }
});
</code></pre>

blocks|key|58050|text|class+MyLayoutManager+extends+LinearLayoutManager+{

++public+MyLayoutManager(Context+context)+{
++++super(context,+LinearLayoutManager.VERTICAL,+false);
++}

++@Override+public+void+smoothScrollToPosition(RecyclerView+recyclerView,
++++++final+RecyclerView.State+state,+final+int+position)+{

++++int+fcvip+=+findFirstCompletelyVisibleItemPosition();
++++int+lcvip+=+findLastCompletelyVisibleItemPosition();

++++if+(position+<+fcvip+%7C%7C+lcvip+<+position)+{
++++++//+scrolling+to+invisible+position

++++++float+fcviY+=+findViewByPosition(fcvip).getY();
++++++float+lcviY+=+findViewByPosition(lcvip).getY();

++++++recyclerView.setOnScrollListener(new+RecyclerView.OnScrollListener()+{

++++++++int+currentState+=+RecyclerView.SCROLL_STATE_IDLE;

++++++++@Override+public+void+onScrollStateChanged(RecyclerView+recyclerView,+int+newState)+{

++++++++++if+(currentState+==+RecyclerView.SCROLL_STATE_SETTLING
++++++++++++++&&+newState+==+RecyclerView.SCROLL_STATE_IDLE)+{

++++++++++++//+recursive+scrolling
++++++++++++smoothScrollToPosition(recyclerView,+state,+position);
++++++++++}

++++++++++currentState+=+newState;
++++++++}

++++++++@Override+public+void+onScrolled(RecyclerView+recyclerView,+int+dx,+int+dy)+{

++++++++++int+fcvip+=+findFirstCompletelyVisibleItemPosition();
++++++++++int+lcvip+=+findLastCompletelyVisibleItemPosition();

++++++++++if+((dy+<+0+&&+fcvip+==+position)+%7C%7C+(dy+>+0+&&+lcvip+==+position))+{
++++++++++++//+stop+scrolling
++++++++++++recyclerView.setOnScrollListener(null);
++++++++++}
++++++++}
++++++});

++++++if+(position+<+fcvip)+{
++++++++//+scroll+up

++++++++recyclerView.smoothScrollBy(0,+(int)+(fcviY+-+lcviY));
++++++}+else+{
++++++++//+scroll+down

++++++++recyclerView.smoothScrollBy(0,+(int)+(lcviY+-+fcviY));
++++++}
++++}+else+{
++++++//+scrolling+to+visible+position

++++++float+fromY+=+findViewByPosition(fcvip).getY();
++++++float+targetY+=+findViewByPosition(position).getY();

++++++recyclerView.smoothScrollBy(0,+(int)+(targetY+-+fromY));
++++}
++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|58051|和|unstyled|58052|MyLayoutManager+layoutManager+=+new+MyLayoutManager(context);
recyclerView.setLayoutManager(layoutManager);

RecyclerView.Adapter+adapter+=+new+YourAdapter();
recyclerView.setAdapter(adapter);

recyclerView.smoothScrollToPosition(adapter.getItemCount()+-+1);|58053|上面的代码可以工作，但它并不流畅，也不酷。|58054|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|F|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<pre><code>class MyLayoutManager extends LinearLayoutManager {

 public MyLayoutManager(Context context) {
 super(context, LinearLayoutManager.VERTICAL, false);
 }

 @Override public void smoothScrollToPosition(RecyclerView recyclerView,
 final RecyclerView.State state, final int position) {

 int fcvip = findFirstCompletelyVisibleItemPosition();
 int lcvip = findLastCompletelyVisibleItemPosition();

 if (position &lt; fcvip || lcvip &lt; position) {
 // scrolling to invisible position

 float fcviY = findViewByPosition(fcvip).getY();
 float lcviY = findViewByPosition(lcvip).getY();

 recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {

 int currentState = RecyclerView.SCROLL_STATE_IDLE;

 @Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) {

 if (currentState == RecyclerView.SCROLL_STATE_SETTLING
 &amp;&amp; newState == RecyclerView.SCROLL_STATE_IDLE) {

 // recursive scrolling
 smoothScrollToPosition(recyclerView, state, position);
 }

 currentState = newState;
 }

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

 int fcvip = findFirstCompletelyVisibleItemPosition();
 int lcvip = findLastCompletelyVisibleItemPosition();

 if ((dy &lt; 0 &amp;&amp; fcvip == position) || (dy &gt; 0 &amp;&amp; lcvip == position)) {
 // stop scrolling
 recyclerView.setOnScrollListener(null);
 }
 }
 });

 if (position &lt; fcvip) {
 // scroll up

 recyclerView.smoothScrollBy(0, (int) (fcviY - lcviY));
 } else {
 // scroll down

 recyclerView.smoothScrollBy(0, (int) (lcviY - fcviY));
 }
 } else {
 // scrolling to visible position

 float fromY = findViewByPosition(fcvip).getY();
 float targetY = findViewByPosition(position).getY();

 recyclerView.smoothScrollBy(0, (int) (targetY - fromY));
 }
 }
}
</code></pre>

and

<pre><code>MyLayoutManager layoutManager = new MyLayoutManager(context);
recyclerView.setLayoutManager(layoutManager);

RecyclerView.Adapter adapter = new YourAdapter();
recyclerView.setAdapter(adapter);

recyclerView.smoothScrollToPosition(adapter.getItemCount() - 1);
</code></pre>

above code works, but it's not smooth and not cool.

blocks|key|58079|text|我知道在这里回答已经很晚了，不过如果有人想知道下面的解决方案的话|type|unstyled|depth|inlineStyleRanges|entityRanges|data|58080|conversationView.smoothScrollToPosition(conversationView.getAdapter().getItemCount()+-+1);|code-block|syntax|javascript|58081|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I know its late to answer here, still if anybody want to know solution is below

<pre><code>conversationView.smoothScrollToPosition(conversationView.getAdapter().getItemCount() - 1);
</code></pre>

blocks|key|4564570|text|只有伊恩的回答能够让我的RecyclerView滚动到指定的位置。然而，当我使用scrollToPosition()之后，RecyclerView不能滚动。smoothScrollToPosition()起作用了，但是当列表很长时，初始动画会使它变得太慢。原因是未删除监听程序。我使用下面的代码删除了当前的ViewTreeObserver，效果很不错。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4564571|++++mRecyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new+ViewTreeObserver.OnGlobalLayoutListener()+{
++++++++@Override
++++++++public+void+onGlobalLayout()+{
++++++++++++mRecyclerView.scrollToPosition(mPosition);
++++++++++++mRecyclerView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
++++++++}
++++});|code-block|syntax|javascript|4564572|entityMap^0|C|C|14|I|1P|C|26|O|49|G|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|L|$]]

Only Ian's answer was able to make my <code>RecyclerView</code> scroll to a specified position. However, The <code>RecyclerView</code> was not able to scroll afterwards when I used <code>scrollToPosition()</code>. <code>smoothScrollToPosition()</code> worked but the initial animation made it too slow when the list was long. 
The reason was the listener was not removed. I used the code below to remove the current <code>ViewTreeObserver</code> and it worked as a charm.

<pre><code> mRecyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
 @Override
 public void onGlobalLayout() {
 mRecyclerView.scrollToPosition(mPosition);
 mRecyclerView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
 }
 });
</code></pre>

blocks|key|4564593|text|如果您的适配器连接了recyclerView，则只需执行以下操作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4564594|mRecyclerView.smoothScrollToPosition(mRecyclerView.getAdapter().getItemCount());|offset|length|style|CODE|4564595|entityMap^0|0|0|28|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

IF you have adapter attached with recyclerView then just do this.

<code>mRecyclerView.smoothScrollToPosition(mRecyclerView.getAdapter().getItemCount());</code>

blocks|key|4564652|text|Roc+answer是一个很大的帮助。我想在其中添加一个小块：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4564653|mRecyclerView.scrollToPosition(mAdapter.getItemCount()+-+1);|code-block|syntax|javascript|4564654|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Roc answer is a great help. I would like to add a small block to it:

<pre><code>mRecyclerView.scrollToPosition(mAdapter.getItemCount() - 1);
</code></pre>

blocks|key|4564674|text|这对我来说非常好用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4564675|AdapterChart+adapterChart+=+new+AdapterChart(getContext(),messageList);
recyclerView.setAdapter(adapterChart);
recyclerView.scrollToPosition(recyclerView.getAdapter().getItemCount()-1);|code-block|syntax|javascript|4564676|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This works perfectly fine for me:

<pre><code>AdapterChart adapterChart = new AdapterChart(getContext(),messageList);
recyclerView.setAdapter(adapterChart);
recyclerView.scrollToPosition(recyclerView.getAdapter().getItemCount()-1);
</code></pre>

blocks|key|4564680|text|在Kotlin：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4564681|recyclerView.viewTreeObserver.addOnGlobalLayoutListener+{+scrollToEnd()+}

private+fun+scrollToEnd()+=
++++++++(adapter.itemCount+-+1).takeIf+{+it+>+0+}?.let(recyclerView::smoothScrollToPosition)|code-block|syntax|javascript|4564682|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

In Kotlin:

<pre><code>recyclerView.viewTreeObserver.addOnGlobalLayoutListener { scrollToEnd() }

private fun scrollToEnd() =
 (adapter.itemCount - 1).takeIf { it &gt; 0 }?.let(recyclerView::smoothScrollToPosition)
</code></pre>

blocks|key|58281|text|这段代码将首先给你最新的帖子，我认为这个答案是有帮助的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|58282|++++mInstaList=(RecyclerView)findViewById(R.id.insta_list);
++++mInstaList.setHasFixedSize(true);

++++LinearLayoutManager+layoutManager+=+new+LinearLayoutManager(this);
++++layoutManager.setOrientation(LinearLayoutManager.VERTICAL);

++++mInstaList.setLayoutManager(layoutManager);
++++layoutManager.setStackFromEnd(true);
++++layoutManager.setReverseLayout(true);|code-block|syntax|javascript|58283|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

this code will give you latest post first, i think this answer is helpful. 

<pre><code> mInstaList=(RecyclerView)findViewById(R.id.insta_list);
 mInstaList.setHasFixedSize(true);

 LinearLayoutManager layoutManager = new LinearLayoutManager(this);
 layoutManager.setOrientation(LinearLayoutManager.VERTICAL);

 mInstaList.setLayoutManager(layoutManager);
 layoutManager.setStackFromEnd(true);
 layoutManager.setReverseLayout(true);
</code></pre>

blocks|key|4564767|text|在发送消息之后和从服务器获取消息之前添加此代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4564768|recyclerView.scrollToPosition(mChatList.size()+-+1);|code-block|syntax|javascript|4564769|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Add this code after sending message and before getting message from server

<pre><code>recyclerView.scrollToPosition(mChatList.size() - 1);
</code></pre>

blocks|key|4564831|text|尝试了一种@galex方法，它在重构之前一直有效。因此，我使用了@yanchenko的答案，并做了一些更改。这可能是因为我从onCreateView()调用了滚动，在那里构建了一个片段视图(可能没有合适的大小)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4564832|private+fun+scrollPhotosToEnd(view:+View)+{
++++view.recycler_view.viewTreeObserver.addOnGlobalLayoutListener(object+:
++++++++ViewTreeObserver.OnGlobalLayoutListener+{
++++++++override+fun+onGlobalLayout()+{
++++++++++++if+(Build.VERSION.SDK_INT+>=+Build.VERSION_CODES.JELLY_BEAN)+{
++++++++++++++++view.recycler_view.viewTreeObserver.removeOnGlobalLayoutListener(this)
++++++++++++}+else+{
++++++++++++++++@Suppress("DEPRECATION")
++++++++++++++++view.recycler_view.viewTreeObserver.removeGlobalOnLayoutListener(this)
++++++++++++}
++++++++++++adapter?.itemCount?.takeIf+{+it+>+0+}?.let+{
++++++++++++++++view.recycler_view.scrollToPosition(it+-+1)
++++++++++++}
++++++++}
++++})
}|code-block|syntax|javascript|4564833|您还可以像在https://stackoverflow.com/a/39001731/2914140中一样添加viewTreeObserver.isAlive检查。|4564834|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/48542833/2914140|1|https://stackoverflow.com/a/48614054/2914140|2|https://stackoverflow.com/a/39001731/2914140^0|1Q|E|5|6|0|W|A|1|0|0|1J|O|6|18|2|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@$9|11|A|12|1|13]|$9|14|A|15|1|16]]|E|$]]|$1|F|3|G|5|H|7|17|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|18|8|@$9|19|A|1A|B|C]]|D|@$9|1B|A|1C|1|1D]]|E|$]]|$1|M|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]|U|$5|P|Q|R|E|$S|V]]|W|$5|P|Q|R|E|$S|X]]]]

Tried a method of <a href="https://stackoverflow.com/a/48542833/2914140">@galex</a>, it worked until refactoring. So I used an answer of <a href="https://stackoverflow.com/a/48614054/2914140">@yanchenko</a> and changed a bit. Probably this is because I called scrolling from <code>onCreateView()</code>, where a fragment view was built (and probably didn't have right size).

<pre><code>private fun scrollPhotosToEnd(view: View) {
 view.recycler_view.viewTreeObserver.addOnGlobalLayoutListener(object :
 ViewTreeObserver.OnGlobalLayoutListener {
 override fun onGlobalLayout() {
 if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.JELLY_BEAN) {
 view.recycler_view.viewTreeObserver.removeOnGlobalLayoutListener(this)
 } else {
 @Suppress("DEPRECATION")
 view.recycler_view.viewTreeObserver.removeGlobalOnLayoutListener(this)
 }
 adapter?.itemCount?.takeIf { it &gt; 0 }?.let {
 view.recycler_view.scrollToPosition(it - 1)
 }
 }
 })
}
</code></pre>

You can also add a check of <code>viewTreeObserver.isAlive</code> like in <a href="https://stackoverflow.com/a/39001731/2914140">https://stackoverflow.com/a/39001731/2914140</a>.

blocks|key|58403|text|第一次进入回收器视图时第一次滚动，然后使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|58404|linearLayoutManager.scrollToPositionWithOffset(messageHashMap.size()-1|code-block|syntax|javascript|58405|输入负数表示向下滚动，表示向上滚动输入正值)；|58406|如果视图的高度非常大，那么scrolltoposition对视图顶部使用特定的偏移量，然后使用|58407|int+overallXScroldl+=chatMessageBinding.rvChat.computeVerticalScrollOffset();
chatMessageBinding.rvChat.smoothScrollBy(0,+Math.abs(overallXScroldl));|58408|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

First time scroll when entering in recycler view first time then use 

<pre><code>linearLayoutManager.scrollToPositionWithOffset(messageHashMap.size()-1
</code></pre>

put in minus for scroll down for scroll up put in positive value);

if the view is very big in height then scrolltoposition particular offset is used for the top of view then you use 

<pre><code>int overallXScroldl =chatMessageBinding.rvChat.computeVerticalScrollOffset();
chatMessageBinding.rvChat.smoothScrollBy(0, Math.abs(overallXScroldl));
</code></pre>

blocks|key|58429|text|如果这些都不起作用，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|58430|您应该尝试使用：|58431|ConstraintLayout+targetView+=+(ConstraintLayout)+recyclerView.findViewHolderForAdapterPosition(adapter.getItemCount()-1).itemView;
targetView.getParent().requestChildFocus(targetView,+targetView);|code-block|syntax|javascript|58432|这样做，您就是在请求显示某个ConstraintLayout+(或您拥有的任何内容)。卷轴是即时的。|58433|我甚至可以在显示键盘的情况下工作。|58434|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

If none of these worked,
you should try to use :
<pre><code>ConstraintLayout targetView = (ConstraintLayout) recyclerView.findViewHolderForAdapterPosition(adapter.getItemCount()-1).itemView;
targetView.getParent().requestChildFocus(targetView, targetView);
</code></pre>
By doing this, you are requesting a certain ConstraintLayout (Or whatever you have) to be displayed. The scroll is instant.
I works even with keyboard shown.

blocks|key|58452|text|如果您正在使用AppBarLayout，则必须在scrollToPosition之前将其隐藏起来|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|58453|entityMap^0|7|C|O|G|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

You must hide <code>AppBarLayout</code> before <code>scrollToPosition</code> if you are using him

blocks|key|4564947|text|您可以滚动到最后一项的底部，如果最后一项的高度太大，则需要进行偏移|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4564948|+private+void+scrollToBottom(final+RecyclerView+recyclerView)+{
++++++++//+scroll+to+last+item+to+get+the+view+of+last+item
++++++++final+LinearLayoutManager+layoutManager+=+(LinearLayoutManager)+recyclerView.getLayoutManager();
++++++++final+RecyclerView.Adapter+adapter+=+recyclerView.getAdapter();
++++++++final+int+lastItemPosition+=+adapter.getItemCount()+-+1;
++++
++++++++layoutManager.scrollToPositionWithOffset(lastItemPosition,+0);
++++++++recyclerView.post(new+Runnable()+{
++++++++++++@Override
++++++++++++public+void+run()+{
++++++++++++++++//+then+scroll+to+specific+offset
++++++++++++++++View+target+=+layoutManager.findViewByPosition(lastItemPosition);
++++++++++++++++if+(target+!=+null)+{
++++++++++++++++++++int+offset+=+recyclerView.getMeasuredHeight()+-+target.getMeasuredHeight();
++++++++++++++++++++layoutManager.scrollToPositionWithOffset(lastItemPosition,+offset);
++++++++++++++++}
++++++++++++}
++++++++});



++++}|code-block|syntax|javascript|4564949|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can scroll to the bottom of the last item, if the height of the last item is too large, you need to offset
<pre><code> private void scrollToBottom(final RecyclerView recyclerView) {
 // scroll to last item to get the view of last item
 final LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
 final RecyclerView.Adapter adapter = recyclerView.getAdapter();
 final int lastItemPosition = adapter.getItemCount() - 1;
 
 layoutManager.scrollToPositionWithOffset(lastItemPosition, 0);
 recyclerView.post(new Runnable() {
 @Override
 public void run() {
 // then scroll to specific offset
 View target = layoutManager.findViewByPosition(lastItemPosition);
 if (target != null) {
 int offset = recyclerView.getMeasuredHeight() - target.getMeasuredHeight();
 layoutManager.scrollToPositionWithOffset(lastItemPosition, offset);
 }
 }
 });



 }
</code></pre>

blocks|key|58491|text|如果您只想从最终使用开始：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|58492|layoutManager.stackFromEnd+=+true|code-block|syntax|javascript|58493|(Kotlin解决方案)|58494|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

If you want just starting from the end use:
<pre><code>layoutManager.stackFromEnd = true
</code></pre>
(Kotlin solution)

blocks|key|4565022|text|如果在使回收器视图滚动到最新版本时遇到问题，请检查回收器视图是否不在nestedScrollView中。那是我的问题。我必须删除nestedScrollview，然后下面的代码就可以工作了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4565023|binding.recyclerView.scrollToPosition(adapter.getItemCount()+-+1);|code-block|syntax|javascript|4565024|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If you are having issues making recyclerview scroll to the latest, check that the recyclerview is not inside a nestedScrollView. That was my issue. I had to remove the nestedScrollview and then the below code worked.
<pre><code>binding.recyclerView.scrollToPosition(adapter.getItemCount() - 1);
</code></pre>

blocks|key|4565051|text|我知道这太晚了，但这对我很有效，所以我回答了这个问题|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4565052|第一,|4565053|LinearLayoutManager+layoutManager=new+LinearLayoutManager(this);
layoutManager.setStackFromEnd(true);
recyclerView.setLayoutManager(layoutManager);|code-block|syntax|javascript|4565054|在那之后,|4565055|database.addValueEventListener(....){
@override
public+void+onDataCange(...){
....
....
//put+this+line+here
recyclerView.smoothScrollToPosition(recyclerView.getAdapter().getItemCount()-1);
}
}|4565056|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

I know this is too late but this worked for me so that i am answering this question
first,
<pre><code>LinearLayoutManager layoutManager=new LinearLayoutManager(this);
layoutManager.setStackFromEnd(true);
recyclerView.setLayoutManager(layoutManager);
</code></pre>
after that,
<pre><code>database.addValueEventListener(....){
@override
public void onDataCange(...){
....
....
//put this line here
recyclerView.smoothScrollToPosition(recyclerView.getAdapter().getItemCount()-1);
}
}
</code></pre>

blocks|key|4565086|text|仅使用重力即可轻松求解|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4565087|Android:layout_gravity=“底部”|4565088|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

use only gravity for easy solution
android:layout_gravity=&quot;bottom&quot;

blocks|key|58658|text|如果你使用kotlin，试试这个|type|unstyled|depth|inlineStyleRanges|entityRanges|data|58659|conversationView.post+{
++++scrollToPosition(conversationView?.adapter.itemCount+-+1)
}|code-block|syntax|javascript|58660|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

if you use kotlin, try this
<pre><code>conversationView.post {
 scrollToPosition(conversationView?.adapter.itemCount - 1)
}
</code></pre>

blocks|key|4565141|text|如果你使用reversedLayout的“聊天界面”，特别是如果你有图片，你可以尝试以下方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4565142|首先，在适配器中注册DataObserver|4565143|+++chatAdapter.registerAdapterDataObserver(object+:+
+++++++++++++++++++++++++RecyclerView.AdapterDataObserver()+{

+++override+fun+onItemRangeInserted(positionStart:+Int+itemCount:+Int)+{

++++++val+messageCount:+Int+=+chatAdapter.itemCount

++++++val+lastVisiblePosition:+Int+=
++++++++++++layoutManager.findLastCompletelyVisibleItemPosition()

+++++++++if+(lastVisiblePosition+==+-1+%7C%7C+positionStart+<=+(messageCount+-+1))+{
++++++++++++recyclerView.scrollToPosition(positionStart)
++++++++}
++++}
})+|code-block|syntax|javascript|4565144|一旦为适配器设置了数据，就会调用该函数|4565145|其次，您必须向recyclerView添加一个滚动监听器，如下所示：|4565146|+++recyclerView.addOnScrollListener(object+
+++++:RecyclerView.OnScrollListener()+{

+++++++override+fun+onScrolled(recyclerView:+RecyclerView,+dx:+Int,+dy:+
++++++++++Int)+{
++++++++++++super.onScrolled(recyclerView,+dx,+dy)

++++++++++val+lastVisiblePosition:+Int+=
++++++++++++++layoutManager.findLastCompletelyVisibleItemPosition()
++++++++if+(lastVisiblePosition+!=+-1+&&+lastVisiblePosition+<+
++++++++++++++++chatAdapter.itemCount+-+1)+{
++++++++++++recyclerView.smoothScrollToPosition(0)
++++++++}
++++}
})|4565147|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|V|8|@]|9|@]|A|$G|H]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

If you working with reversedLayout &quot;chat interface&quot; specially if you have images, you can try the following:
first, register DataObserver with the adapter
<pre><code> chatAdapter.registerAdapterDataObserver(object : 
 RecyclerView.AdapterDataObserver() {

 override fun onItemRangeInserted(positionStart: Int itemCount: Int) {

 val messageCount: Int = chatAdapter.itemCount

 val lastVisiblePosition: Int =
 layoutManager.findLastCompletelyVisibleItemPosition()

 if (lastVisiblePosition == -1 || positionStart &lt;= (messageCount - 1)) {
 recyclerView.scrollToPosition(positionStart)
 }
 }
}) 
</code></pre>
this will be called once you set the data for the adapter
second, you have to add a scroll listener to the recyclerView like this:
<pre><code> recyclerView.addOnScrollListener(object 
 :RecyclerView.OnScrollListener() {

 override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: 
 Int) {
 super.onScrolled(recyclerView, dx, dy)

 val lastVisiblePosition: Int =
 layoutManager.findLastCompletelyVisibleItemPosition()
 if (lastVisiblePosition != -1 &amp;&amp; lastVisiblePosition &lt; 
 chatAdapter.itemCount - 1) {
 recyclerView.smoothScrollToPosition(0)
 }
 }
})
</code></pre>

I'd like to scroll to the bottom of the RecyclerView list after loading the activity.

<pre><code>GENERIC_MESSAGE_LIST = (ArrayList) intent.getExtras().getParcelableArrayList(ConversationsAdapter.EXTRA_MESSAGE);
conversationView = (RecyclerView) findViewById(R.id.list_messages);
conversationView.setHasFixedSize(true);
conversationViewLayoutManager = new LinearLayoutManager(this);
conversationView.setLayoutManager(conversationViewLayoutManager);
conversationViewAdapter = new ConversationAdapter(GENERIC_MESSAGE_LIST, this);
conversationView.setAdapter(conversationViewAdapter);
</code></pre>

<code>conversationView.scrollTo(...)</code> throws an exception about being not supported in RecyclerView, and <code>conversationView.scrollToPosition(...)</code> doesn't seem to do anything.

After the above block of code, I added

<pre><code>conversationView.scrollToPosition(GENERIC_MESSAGE_LIST.size() + 1)
</code></pre>

which doesn't work. There are 30 elements in <code>GENERIC_MESSAGE_LIST</code>.

How to scroll to the bottom of a RecyclerView? scrollToPosition doesn't work

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

加载活动后，我想滚动到RecyclerView列表的底部。GENERIC_MESSAGE_LIST = (ArrayList) intent.getExtras().getParcelableArrayList(ConversationsAdapter.EXTRA_MESSAGE);conversationView =...

问如何滚动到RecyclerView的底部？scrollToPosition不工作
EN

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何滚动到RecyclerView的底部？scrollToPosition不工作EN

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何滚动到RecyclerView的底部？scrollToPosition不工作
EN