GridLayoutManagerを使用してRecyclerViewで列間隔を設定するにはどうすればよいですか?レイアウト内のマージン/パディングを設定しても効果がありません。
GridLayoutManagerを使用してRecyclerViewで列間隔を設定するにはどうすればよいですか?レイアウト内のマージン/パディングを設定しても効果がありません。
回答:
RecyclerViewsはItemDecorationの概念をサポートします:特別なオフセットと各要素の周りの描画。この回答で見られるように、あなたは使うことができます
public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
private int space;
public SpacesItemDecoration(int space) {
this.space = space;
}
@Override
public void getItemOffsets(Rect outRect, View view,
RecyclerView parent, RecyclerView.State state) {
outRect.left = space;
outRect.right = space;
outRect.bottom = space;
// Add top margin only for the first item to avoid double space between items
if (parent.getChildLayoutPosition(view) == 0) {
outRect.top = space;
} else {
outRect.top = 0;
}
}
}
次にそれを追加します
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
int spacingInPixels = getResources().getDimensionPixelSize(R.dimen.spacing);
mRecyclerView.addItemDecoration(new SpacesItemDecoration(spacingInPixels));
RecyclerView
(そしてを使用している場合clipToPadding="false"
)、少し再構成できます。ただし、そうでない場合は、ifチェックを最後に移動するだけです(最後の項目の下部のパディングが必要なため)。
GridLayoutManager
ます。回答は複数列/行レイアウトでは機能しません
次のコードは適切に機能し、各列の幅は同じです:
public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {
private int spanCount;
private int spacing;
private boolean includeEdge;
public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {
this.spanCount = spanCount;
this.spacing = spacing;
this.includeEdge = includeEdge;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
int position = parent.getChildAdapterPosition(view); // item position
int column = position % spanCount; // item column
if (includeEdge) {
outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)
if (position < spanCount) { // top edge
outRect.top = spacing;
}
outRect.bottom = spacing; // item bottom
} else {
outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
if (position >= spanCount) {
outRect.top = spacing; // item top
}
}
}
}
int spanCount = 3; // 3 columns
int spacing = 50; // 50px
boolean includeEdge = false;
recyclerView.addItemDecoration(new GridSpacingItemDecoration(spanCount, spacing, includeEdge));
int spanCount = 3; // 3 columns
int spacing = 50; // 50px
boolean includeEdge = true;
recyclerView.addItemDecoration(new GridSpacingItemDecoration(spanCount, spacing, includeEdge));
以下は、アイテムの周りに等間隔で、アイテムサイズを等しくしたい場合の段階的なシンプルなソリューションです。
public class ItemOffsetDecoration extends RecyclerView.ItemDecoration {
private int mItemOffset;
public ItemOffsetDecoration(int itemOffset) {
mItemOffset = itemOffset;
}
public ItemOffsetDecoration(@NonNull Context context, @DimenRes int itemOffsetId) {
this(context.getResources().getDimensionPixelSize(itemOffsetId));
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
outRect.set(mItemOffset, mItemOffset, mItemOffset, mItemOffset);
}
}
ソースコードで、
アイテムのオフセット値に追加ItemOffsetDecoration
するRecyclerView.
値は、アイテム間のスペースとして追加する実際の値の半分のサイズにする必要があります。
mRecyclerView.setLayoutManager(new GridLayoutManager(context, NUM_COLUMNS);
ItemOffsetDecoration itemDecoration = new ItemOffsetDecoration(context, R.dimen.item_offset);
mRecyclerView.addItemDecoration(itemDecoration);
また、アイテムのオフセット値をそののパディングとして設定しRecyclerView
、を指定しますandroid:clipToPadding=false
。
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerview_grid"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:padding="@dimen/item_offset"/>
これを試して。すべての周りで等間隔に処理されます。List、Grid、およびStaggeredGridの両方で機能します。
更新されたコードは、スパンや方向などのほとんどのコーナーケースを処理する必要があります。GridLayoutManagerでsetSpanSizeLookup()を使用する場合、パフォーマンス上の理由からsetSpanIndexCacheEnabled()を設定することをお勧めします。
StaggeredGridを使用すると、子のインデックスが奇妙になり追跡が困難になるバグがあるようです。そのため、以下のコードはStaggeredGridLayoutManagerでうまく機能しない可能性があります。
public class ListSpacingDecoration extends RecyclerView.ItemDecoration {
private static final int VERTICAL = OrientationHelper.VERTICAL;
private int orientation = -1;
private int spanCount = -1;
private int spacing;
private int halfSpacing;
public ListSpacingDecoration(Context context, @DimenRes int spacingDimen) {
spacing = context.getResources().getDimensionPixelSize(spacingDimen);
halfSpacing = spacing / 2;
}
public ListSpacingDecoration(int spacingPx) {
spacing = spacingPx;
halfSpacing = spacing / 2;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
if (orientation == -1) {
orientation = getOrientation(parent);
}
if (spanCount == -1) {
spanCount = getTotalSpan(parent);
}
int childCount = parent.getLayoutManager().getItemCount();
int childIndex = parent.getChildAdapterPosition(view);
int itemSpanSize = getItemSpanSize(parent, childIndex);
int spanIndex = getItemSpanIndex(parent, childIndex);
/* INVALID SPAN */
if (spanCount < 1) return;
setSpacings(outRect, parent, childCount, childIndex, itemSpanSize, spanIndex);
}
protected void setSpacings(Rect outRect, RecyclerView parent, int childCount, int childIndex, int itemSpanSize, int spanIndex) {
outRect.top = halfSpacing;
outRect.bottom = halfSpacing;
outRect.left = halfSpacing;
outRect.right = halfSpacing;
if (isTopEdge(parent, childCount, childIndex, itemSpanSize, spanIndex)) {
outRect.top = spacing;
}
if (isLeftEdge(parent, childCount, childIndex, itemSpanSize, spanIndex)) {
outRect.left = spacing;
}
if (isRightEdge(parent, childCount, childIndex, itemSpanSize, spanIndex)) {
outRect.right = spacing;
}
if (isBottomEdge(parent, childCount, childIndex, itemSpanSize, spanIndex)) {
outRect.bottom = spacing;
}
}
@SuppressWarnings("all")
protected int getTotalSpan(RecyclerView parent) {
RecyclerView.LayoutManager mgr = parent.getLayoutManager();
if (mgr instanceof GridLayoutManager) {
return ((GridLayoutManager) mgr).getSpanCount();
} else if (mgr instanceof StaggeredGridLayoutManager) {
return ((StaggeredGridLayoutManager) mgr).getSpanCount();
} else if (mgr instanceof LinearLayoutManager) {
return 1;
}
return -1;
}
@SuppressWarnings("all")
protected int getItemSpanSize(RecyclerView parent, int childIndex) {
RecyclerView.LayoutManager mgr = parent.getLayoutManager();
if (mgr instanceof GridLayoutManager) {
return ((GridLayoutManager) mgr).getSpanSizeLookup().getSpanSize(childIndex);
} else if (mgr instanceof StaggeredGridLayoutManager) {
return 1;
} else if (mgr instanceof LinearLayoutManager) {
return 1;
}
return -1;
}
@SuppressWarnings("all")
protected int getItemSpanIndex(RecyclerView parent, int childIndex) {
RecyclerView.LayoutManager mgr = parent.getLayoutManager();
if (mgr instanceof GridLayoutManager) {
return ((GridLayoutManager) mgr).getSpanSizeLookup().getSpanIndex(childIndex, spanCount);
} else if (mgr instanceof StaggeredGridLayoutManager) {
return childIndex % spanCount;
} else if (mgr instanceof LinearLayoutManager) {
return 0;
}
return -1;
}
@SuppressWarnings("all")
protected int getOrientation(RecyclerView parent) {
RecyclerView.LayoutManager mgr = parent.getLayoutManager();
if (mgr instanceof LinearLayoutManager) {
return ((LinearLayoutManager) mgr).getOrientation();
} else if (mgr instanceof GridLayoutManager) {
return ((GridLayoutManager) mgr).getOrientation();
} else if (mgr instanceof StaggeredGridLayoutManager) {
return ((StaggeredGridLayoutManager) mgr).getOrientation();
}
return VERTICAL;
}
protected boolean isLeftEdge(RecyclerView parent, int childCount, int childIndex, int itemSpanSize, int spanIndex) {
if (orientation == VERTICAL) {
return spanIndex == 0;
} else {
return (childIndex == 0) || isFirstItemEdgeValid((childIndex < spanCount), parent, childIndex);
}
}
protected boolean isRightEdge(RecyclerView parent, int childCount, int childIndex, int itemSpanSize, int spanIndex) {
if (orientation == VERTICAL) {
return (spanIndex + itemSpanSize) == spanCount;
} else {
return isLastItemEdgeValid((childIndex >= childCount - spanCount), parent, childCount, childIndex, spanIndex);
}
}
protected boolean isTopEdge(RecyclerView parent, int childCount, int childIndex, int itemSpanSize, int spanIndex) {
if (orientation == VERTICAL) {
return (childIndex == 0) || isFirstItemEdgeValid((childIndex < spanCount), parent, childIndex);
} else {
return spanIndex == 0;
}
}
protected boolean isBottomEdge(RecyclerView parent, int childCount, int childIndex, int itemSpanSize, int spanIndex) {
if (orientation == VERTICAL) {
return isLastItemEdgeValid((childIndex >= childCount - spanCount), parent, childCount, childIndex, spanIndex);
} else {
return (spanIndex + itemSpanSize) == spanCount;
}
}
protected boolean isFirstItemEdgeValid(boolean isOneOfFirstItems, RecyclerView parent, int childIndex) {
int totalSpanArea = 0;
if (isOneOfFirstItems) {
for (int i = childIndex; i >= 0; i--) {
totalSpanArea = totalSpanArea + getItemSpanSize(parent, i);
}
}
return isOneOfFirstItems && totalSpanArea <= spanCount;
}
protected boolean isLastItemEdgeValid(boolean isOneOfLastItems, RecyclerView parent, int childCount, int childIndex, int spanIndex) {
int totalSpanRemaining = 0;
if (isOneOfLastItems) {
for (int i = childIndex; i < childCount; i++) {
totalSpanRemaining = totalSpanRemaining + getItemSpanSize(parent, i);
}
}
return isOneOfLastItems && (totalSpanRemaining <= spanCount - spanIndex);
}
}
それが役に立てば幸い。
次のコードは、StaggeredGridLayoutManager、GridLayoutManager、およびLinearLayoutManagerを処理します。
public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
private int halfSpace;
public SpacesItemDecoration(int space) {
this.halfSpace = space / 2;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
if (parent.getPaddingLeft() != halfSpace) {
parent.setPadding(halfSpace, halfSpace, halfSpace, halfSpace);
parent.setClipToPadding(false);
}
outRect.top = halfSpace;
outRect.bottom = halfSpace;
outRect.left = halfSpace;
outRect.right = halfSpace;
}
}
次にそれを使用します
mRecyclerView.addItemDecoration(new SpacesItemDecoration(mMargin));
SpaceItemDecoration
実際にパディングを親(リサイクラービュー)に追加します。
halfSpace
xmlでパディングを親に設定しなかった場合、パディングのみが表示されました(右側に)
「spanCount」(列数)を必要としないソリューションは次のとおりです。GridAutofitLayoutManagerを使用しているため、これを使用しています(必要なセルサイズに従って列数を計算しています)。
(これはGridLayoutManagerでのみ機能することに注意してください)
public class GridSpacesItemDecoration extends RecyclerView.ItemDecoration {
private final boolean includeEdge;
private int spacing;
public GridSpacesItemDecoration(int spacing, boolean includeEdge) {
this.spacing = spacing;
this.includeEdge = includeEdge;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
if (parent.getLayoutManager() instanceof GridLayoutManager) {
GridLayoutManager layoutManager = (GridLayoutManager)parent.getLayoutManager();
int spanCount = layoutManager.getSpanCount();
int position = parent.getChildAdapterPosition(view); // item position
int column = position % spanCount; // item column
if (includeEdge) {
outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)
if (position < spanCount) { // top edge
outRect.top = spacing;
}
outRect.bottom = spacing; // item bottom
} else {
outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
if (position >= spanCount) {
outRect.top = spacing; // item top
}
}
}
}
}
ここにGridAutofitLayoutManagerがあり、誰でも興味があります:
public class GridAutofitLayoutManager extends GridLayoutManager {
private int mColumnWidth;
private boolean mColumnWidthChanged = true;
public GridAutofitLayoutManager(Context context, int columnWidth)
{
/* Initially set spanCount to 1, will be changed automatically later. */
super(context, 1);
setColumnWidth(checkedColumnWidth(context, columnWidth));
}
public GridAutofitLayoutManager(Context context,int unit, int columnWidth)
{
/* Initially set spanCount to 1, will be changed automatically later. */
super(context, 1);
int pixColumnWidth = (int) TypedValue.applyDimension(unit, columnWidth, context.getResources().getDisplayMetrics());
setColumnWidth(checkedColumnWidth(context, pixColumnWidth));
}
public GridAutofitLayoutManager(Context context, int columnWidth, int orientation, boolean reverseLayout)
{
/* Initially set spanCount to 1, will be changed automatically later. */
super(context, 1, orientation, reverseLayout);
setColumnWidth(checkedColumnWidth(context, columnWidth));
}
private int checkedColumnWidth(Context context, int columnWidth)
{
if (columnWidth <= 0)
{
/* Set default columnWidth value (48dp here). It is better to move this constant
to static constant on top, but we need context to convert it to dp, so can't really
do so. */
columnWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 48,
context.getResources().getDisplayMetrics());
}
return columnWidth;
}
public void setColumnWidth(int newColumnWidth)
{
if (newColumnWidth > 0 && newColumnWidth != mColumnWidth)
{
mColumnWidth = newColumnWidth;
mColumnWidthChanged = true;
}
}
@Override
public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state)
{
int width = getWidth();
int height = getHeight();
if (mColumnWidthChanged && mColumnWidth > 0 && width > 0 && height > 0)
{
int totalSpace;
if (getOrientation() == VERTICAL)
{
totalSpace = width - getPaddingRight() - getPaddingLeft();
}
else
{
totalSpace = height - getPaddingTop() - getPaddingBottom();
}
int spanCount = Math.max(1, totalSpace / mColumnWidth);
setSpanCount(spanCount);
mColumnWidthChanged = false;
}
super.onLayoutChildren(recycler, state);
}
}
最後に:
mDevicePhotosView.setLayoutManager(new GridAutofitLayoutManager(getContext(), getResources().getDimensionPixelSize(R.dimen.item_size)));
mDevicePhotosView.addItemDecoration(new GridSpacesItemDecoration(Util.dpToPx(getContext(), 2),true));
layoutManager.getPosition(view)
にレイアウトマネージャーで位置を確認できます。その後、ヘッダーになる位置がゼロであるかどうかを確認します。また、この方法により、任意の位置に別のヘッダーを追加できます。)
簡単な解決策は1つだけで、必要な場所に覚えて実装できます。バグもおかしな計算もありません。カード/アイテムのレイアウトにマージンを入れ、RecyclerViewにパディングと同じサイズを入れます。
item_layout.xml
<CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:margin="10dp">
activity_layout.xml
<RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp"/>
すべてのデバイスでアイテムのサイズを修正したい場合RecyclerView
。あなたはこのようにすることができます
public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {
private int mSpanCount;
private float mItemSize;
public GridSpacingItemDecoration(int spanCount, int itemSize) {
this.mSpanCount = spanCount;
mItemSize = itemSize;
}
@Override
public void getItemOffsets(final Rect outRect, final View view, RecyclerView parent,
RecyclerView.State state) {
final int position = parent.getChildLayoutPosition(view);
final int column = position % mSpanCount;
final int parentWidth = parent.getWidth();
int spacing = (int) (parentWidth - (mItemSize * mSpanCount)) / (mSpanCount + 1);
outRect.left = spacing - column * spacing / mSpanCount;
outRect.right = (column + 1) * spacing / mSpanCount;
if (position < mSpanCount) {
outRect.top = spacing;
}
outRect.bottom = spacing;
}
}
recyclerview_item.xml
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="@dimen/recycler_view_item_width"
...
>
...
</LinearLayout>
dimens.xml
<dimen name="recycler_view_item_width">60dp</dimen>
アクティビティ
int numberOfColumns = 3;
mRecyclerView.setLayoutManager(new GridLayoutManager(this, numberOfColumns));
mRecyclerView.setAdapter(...);
mRecyclerView.addItemDecoration(new GridSpacingItemDecoration(3,
getResources().getDimensionPixelSize(R.dimen.recycler_view_item_width)));
選択した答えはほぼ完璧ですが、スペースによっては、アイテムの幅が等しくない場合があります。(私の場合、それは重要でした)。だから私は少しスペースを増やすこのコードに終わったので、アイテムはすべて同じ幅です。
class GridSpacingItemDecoration(private val columnCount: Int, @Px preferredSpace: Int, private val includeEdge: Boolean): RecyclerView.ItemDecoration() {
/**
* In this algorithm space should divide by 3 without remnant or width of items can have a difference
* and we want them to be exactly the same
*/
private val space = if (preferredSpace % 3 == 0) preferredSpace else (preferredSpace + (3 - preferredSpace % 3))
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State?) {
val position = parent.getChildAdapterPosition(view)
if (includeEdge) {
when {
position % columnCount == 0 -> {
outRect.left = space
outRect.right = space / 3
}
position % columnCount == columnCount - 1 -> {
outRect.right = space
outRect.left = space / 3
}
else -> {
outRect.left = space * 2 / 3
outRect.right = space * 2 / 3
}
}
if (position < columnCount) {
outRect.top = space
}
outRect.bottom = space
} else {
when {
position % columnCount == 0 -> outRect.right = space * 2 / 3
position % columnCount == columnCount - 1 -> outRect.left = space * 2 / 3
else -> {
outRect.left = space / 3
outRect.right = space / 3
}
}
if (position >= columnCount) {
outRect.top = space
}
}
}
}
columnCount == 1 -> { outRect.left = space outRect.right = space }
@edwardaaが提供するコードをコピーして、RTLをサポートするのに最適にします。
public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {
private int spanCount;
private int spacing;
private boolean includeEdge;
private int headerNum;
private boolean isRtl = TextUtilsCompat.getLayoutDirectionFromLocale(Locale.getDefault()) == ViewCompat.LAYOUT_DIRECTION_RTL;
public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge, int headerNum) {
this.spanCount = spanCount;
this.spacing = spacing;
this.includeEdge = includeEdge;
this.headerNum = headerNum;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
int position = parent.getChildAdapterPosition(view) - headerNum; // item position
if (position >= 0) {
int column = position % spanCount; // item column
if(isRtl) {
column = spanCount - 1 - column;
}
if (includeEdge) {
outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)
if (position < spanCount) { // top edge
outRect.top = spacing;
}
outRect.bottom = spacing; // item bottom
} else {
outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
if (position >= spanCount) {
outRect.top = spacing; // item top
}
}
} else {
outRect.left = 0;
outRect.right = 0;
outRect.top = 0;
outRect.bottom = 0;
}
}
}
上記の回答により、GridLayoutManagerおよびLinearLayoutManagerのマージン処理を設定する方法が明確になりました。
しかし、StaggeredGridLayoutManagerについては、Pirdad Sakhizadaの回答は「StaggeredGridLayoutManagerではうまく機能しない可能性がある」と述べています。IndexOfSpanに関する問題です。
あなたはこの方法でそれを得ることができます:
private static class MyItemDecoration extends RecyclerView.ItemDecoration {
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
int index = ((StaggeredGridLayoutManager.LayoutParams) view.getLayoutParams()).getSpanIndex();
}
}
public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {
private int spanCount;
private int spacing;
private boolean includeEdge;
public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {
this.spanCount = spanCount;
this.spacing = spacing;
this.includeEdge = includeEdge;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
StaggeredGridLayoutManager.LayoutParams params = (StaggeredGridLayoutManager.LayoutParams) view.getLayoutParams();
int column = params.getSpanIndex();
if (includeEdge) {
outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)
if (position < spanCount) { // top edge
outRect.top = spacing;
}
outRect.bottom = spacing; // item bottom
} else {
outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
if (position >= spanCount) {
outRect.top = spacing; // item top
}
}
}
}
edwardaaの回答とは少し異なりますが、違いは列の決定方法です。これは、さまざまな高さのアイテムなどの場合、単純に%では列を決定できないためです。 spanCount
class VerticalGridSpacingDecoration(private val spacing: Int) : RecyclerView.ItemDecoration() {
override fun getItemOffsets(
outRect: Rect,
view: View,
parent: RecyclerView,
state: State
) {
val layoutManager = parent.layoutManager as? GridLayoutManager
if (layoutManager == null || layoutManager.orientation != VERTICAL) {
return super.getItemOffsets(outRect, view, parent, state)
}
val spanCount = layoutManager.spanCount
val position = parent.getChildAdapterPosition(view)
val column = position % spanCount
with(outRect) {
left = if (column == 0) 0 else spacing / 2
right = if (column == spanCount.dec()) 0 else spacing / 2
top = if (position < spanCount) 0 else spacing
}
}
}
SpacesItemDecoration
これがnumOfColumsとスペースを上、下、左、右に均等に取ることができる私の変更です。
public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
private int space;
private int mNumCol;
public SpacesItemDecoration(int space, int numCol) {
this.space = space;
this.mNumCol=numCol;
}
@Override
public void getItemOffsets(Rect outRect, View view,
RecyclerView parent, RecyclerView.State state) {
//outRect.right = space;
outRect.bottom = space;
//outRect.left = space;
//Log.d("ttt", "item position" + parent.getChildLayoutPosition(view));
int position=parent.getChildLayoutPosition(view);
if(mNumCol<=2) {
if (position == 0) {
outRect.left = space;
outRect.right = space / 2;
} else {
if ((position % mNumCol) != 0) {
outRect.left = space / 2;
outRect.right = space;
} else {
outRect.left = space;
outRect.right = space / 2;
}
}
}else{
if (position == 0) {
outRect.left = space;
outRect.right = space / 2;
} else {
if ((position % mNumCol) == 0) {
outRect.left = space;
outRect.right = space/2;
} else if((position % mNumCol) == (mNumCol-1)){
outRect.left = space/2;
outRect.right = space;
}else{
outRect.left=space/2;
outRect.right=space/2;
}
}
}
if(position<mNumCol){
outRect.top=space;
}else{
outRect.top=0;
}
// Add top margin only for the first item to avoid double space between items
/*
if (parent.getChildLayoutPosition(view) == 0 ) {
} else {
outRect.top = 0;
}*/
}
}
ロジックで以下のコードを使用します。
recyclerView.addItemDecoration(new SpacesItemDecoration(spacingInPixels, numCol));
すべてのLayoutManagerで機能するXMLのみを使用して、この問題の非常にシンプルでありながら柔軟なソリューションがあります。
Xの等間隔(たとえば、8 dp)が必要だとします。
CardViewアイテムを別のレイアウトでラップする
外側のレイアウトにX / 2(4 dp)のパディングを与える
レイアウトの外側の背景を透明にする
...
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="200dp"
android:layout_height="200dp"
android:background="@android:color/transparent"
android:padding="4dip">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.CardView>
</LinearLayout>
...
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="4dp" />
以上です。Xの完全な間隔(8 dp)があります。
staggeredLayoutManager(https://imgur.com/XVutH5uなど)に問題がある場合
recyclerViewのメソッド:
getChildAdapterPosition(view)
getChildLayoutPosition(view)
インデックスとして-1を返すことがあるため、itemDecorの設定で問題が発生する可能性があります。私の解決策は、廃止されたItemDecorationのメソッドをオーバーライドすることです。
public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent)
初心者の代わりに:
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, State state)
このような:
recyclerView.addItemDecoration(new RecyclerView.ItemDecoration() {
@Override
public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
TheAdapter.VH vh = (TheAdapter.VH) recyclerView.findViewHolderForAdapterPosition(itemPosition);
View itemView = vh.itemView; //itemView is the base view of viewHolder
//or instead of the 2 lines above maybe it's possible to use View itemView = layoutManager.findViewByPosition(itemPosition) ... NOT TESTED
StaggeredGridLayoutManager.LayoutParams itemLayoutParams = (StaggeredGridLayoutManager.LayoutParams) itemView.getLayoutParams();
int spanIndex = itemLayoutParams.getSpanIndex();
if (spanIndex == 0)
...
else
...
}
});
これまでのところ私のために働くようです:)
これはRecyclerView
ヘッダーでも機能します。
public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {
private int spanCount;
private int spacing;
private boolean includeEdge;
private int headerNum;
public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge, int headerNum) {
this.spanCount = spanCount;
this.spacing = spacing;
this.includeEdge = includeEdge;
this.headerNum = headerNum;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
int position = parent.getChildAdapterPosition(view) - headerNum; // item position
if (position >= 0) {
int column = position % spanCount; // item column
if (includeEdge) {
outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)
if (position < spanCount) { // top edge
outRect.top = spacing;
}
outRect.bottom = spacing; // item bottom
} else {
outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
if (position >= spanCount) {
outRect.top = spacing; // item top
}
}
} else {
outRect.left = 0;
outRect.right = 0;
outRect.top = 0;
outRect.bottom = 0;
}
}
}
}
yqritcの答えは私にとって完璧に機能しました。Kotlinを使用していたので、ここではそれと同等です。
class ItemOffsetDecoration : RecyclerView.ItemDecoration {
// amount to add to padding
private val _itemOffset: Int
constructor(itemOffset: Int) {
_itemOffset = itemOffset
}
constructor(@NonNull context: Context, @DimenRes itemOffsetId: Int){
_itemOffset = context.resources.getDimensionPixelSize(itemOffsetId)
}
/**
* Applies padding to all sides of the [Rect], which is the container for the view
*/
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView,state: RecyclerView.State) {
super.getItemOffsets(outRect, view, parent, state)
outRect.set(_itemOffset, _itemOffset, _itemOffset, _itemOffset)
}
}
他はすべて同じです。
最終的には、GridLayoutManagerとHeaderViewを使用して、RecyclerViewでも同じようにしました。
以下のコードでは、すべてのアイテムの間に4 dpのスペースを設定します(すべてのアイテムの周りに2 dp、リサイクラービュー全体の周りに2 dpのパディング)。
layout.xml
<android.support.v7.widget.RecyclerView
android:id="@+id/recycleview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="2dp" />
フラグメント/アクティビティ
GridLayoutManager manager = new GridLayoutManager(getContext(), 3);
recyclerView.setLayoutManager(manager);
int spacingInPixels = Utils.dpToPx(2);
recyclerView.addItemDecoration(new SpacesItemDecoration(spacingInPixels));
SpaceItemDecoration.java
public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
private int mSpacing;
public SpacesItemDecoration(int spacing) {
mSpacing = spacing;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView recyclerView, RecyclerView.State state) {
outRect.left = mSpacing;
outRect.top = mSpacing;
outRect.right = mSpacing;
outRect.bottom = mSpacing;
}
}
Utils.java
public static int dpToPx(final float dp) {
return Math.round(dp * (Resources.getSystem().getDisplayMetrics().xdpi / DisplayMetrics.DENSITY_DEFAULT));
}
作らへhttps://stackoverflow.com/a/29905000/1649371私は、次の方法を変更する必要がありました(上記の)ソリューションの仕事(およびすべての後続の呼び出し)
@SuppressWarnings("all")
protected int getItemSpanSize(RecyclerView parent, View view, int childIndex) {
RecyclerView.LayoutManager mgr = parent.getLayoutManager();
if (mgr instanceof GridLayoutManager) {
return ((GridLayoutManager) mgr).getSpanSizeLookup().getSpanSize(childIndex);
} else if (mgr instanceof StaggeredGridLayoutManager) {
return ((StaggeredGridLayoutManager.LayoutParams) view.getLayoutParams()).isFullSpan() ? spanCount : 1;
} else if (mgr instanceof LinearLayoutManager) {
return 1;
}
return -1;
}
@SuppressWarnings("all")
protected int getItemSpanIndex(RecyclerView parent, View view, int childIndex) {
RecyclerView.LayoutManager mgr = parent.getLayoutManager();
if (mgr instanceof GridLayoutManager) {
return ((GridLayoutManager) mgr).getSpanSizeLookup().getSpanIndex(childIndex, spanCount);
} else if (mgr instanceof StaggeredGridLayoutManager) {
return ((StaggeredGridLayoutManager.LayoutParams) view.getLayoutParams()).getSpanIndex();
} else if (mgr instanceof LinearLayoutManager) {
return 0;
}
return -1;
}
リストとグリッドを切り替えるトグルスイッチがある場合は、recyclerView.removeItemDecoration()
新しいItemデコレーションを設定する前に呼び出すことを忘れないでください。そうでない場合、間隔の新しい計算は正しくありません。
このようなもの。
recyclerView.removeItemDecoration(gridItemDecorator)
recyclerView.removeItemDecoration(listItemDecorator)
if (showAsList){
recyclerView.layoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)
recyclerView.addItemDecoration(listItemDecorator)
}
else{
recyclerView.layoutManager = GridLayoutManager(this, spanCount)
recyclerView.addItemDecoration(gridItemDecorator)
}
GridLayoutManagerでヘッダーを使用している場合は、グリッド間の間隔にkotlinで記述された次のコードを使用します。
inner class SpacesItemDecoration(itemSpace: Int) : RecyclerView.ItemDecoration() {
var space: Int = itemSpace
override fun getItemOffsets(outRect: Rect?, view: View?, parent: RecyclerView?, state: RecyclerView.State?) {
super.getItemOffsets(outRect, view, parent, state)
val position = parent!!.getChildAdapterPosition(view)
val viewType = parent.adapter.getItemViewType(position)
//check to not to set any margin to header item
if (viewType == GridViewAdapter.TYPE_HEADER) {
outRect!!.top = 0
outRect.left = 0
outRect.right = 0
outRect.bottom = 0
} else {
outRect!!.left = space
outRect.right = space
outRect.bottom = space
if (parent.getChildLayoutPosition(view) == 0) {
outRect.top = space
} else {
outRect.top = 0
}
}
}
}
そして、合格ItemDecoration
にrecyclerview
など
mIssueGridView.addItemDecoration(SpacesItemDecoration(10))
edwardaaの回答https://stackoverflow.com/a/30701422/2227031
注意すべきもう1つの点は、
合計間隔と合計itemWidthが画面の幅と等しくない場合は、たとえば、アダプターonBindViewHolderメソッドでitemWidthを調整する必要もあります。
Utils.init(_mActivity);
int width = 0;
if (includeEdge) {
width = ScreenUtils.getScreenWidth() - spacing * (spanCount + 1);
} else {
width = ScreenUtils.getScreenWidth() - spacing * (spanCount - 1);
}
int itemWidth = width / spanCount;
ConstraintLayout.LayoutParams layoutParams = (ConstraintLayout.LayoutParams) holder.imageViewAvatar.getLayoutParams();
// suppose the width and height are the same
layoutParams.width = itemWidth;
layoutParams.height = itemWidth;
holder.imageViewAvatar.setLayoutParams(layoutParams);
edwardaaのすばらしい回答に基づいて作成したKotlinバージョン
class RecyclerItemDecoration(private val spanCount: Int, private val spacing: Int) : RecyclerView.ItemDecoration() {
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
val spacing = Math.round(spacing * parent.context.resources.displayMetrics.density)
val position = parent.getChildAdapterPosition(view)
val column = position % spanCount
outRect.left = spacing - column * spacing / spanCount
outRect.right = (column + 1) * spacing / spanCount
outRect.top = if (position < spanCount) spacing else 0
outRect.bottom = spacing
}
}
GridLayoutManager
とオーバーライドを試みましたgenerateDefaultLayoutParams()
か?