Android 装饰RecyclerView（使用GridLayoutManager）以显示项目之间的分隔符
什么是装饰RecyclerView的最好和最简单的方法，使其具有这样的外观和感觉 这里的主要挑战是仅在项目之间使用分隔符，而不是在项目和屏幕左/右边框之间使用分隔符Android 装饰RecyclerView（使用GridLayoutManager）以显示项目之间的分隔符,android,android-recyclerview,Android,Android Recyclerview,什么是装饰RecyclerView的最好和最简单的方法，使其具有这样的外观和感觉 这里的主要挑战是仅在项目之间使用分隔符，而不是在项目和屏幕左/右边框之间使用分隔符 有什么想法吗？我不知道你为什么需要它，但是这个UI很容易用RecyclerView decorator实现 <!--Integer Value that number of column in RecyclerView--> <integer name="photo_list_preview_columns"&g
有什么想法吗？我不知道你为什么需要它，但是这个UI很容易用RecyclerView decorator实现
<!--Integer Value that number of column in RecyclerView-->
<integer name="photo_list_preview_columns">3</integer>
<!-- inter spacing between RecyclerView's Item-->
<dimen name="photos_list_spacing">10dp</dimen>
导入android.graphics.Rect；
导入android.support.v7.widget.RecyclerView；
导入android.view.view；
公共类ItemDecorationAlbumColumns扩展了RecyclerView.ItemDecoration{
私有int mSizeGridSpacingPx；
私有int-mgridize；
私有布尔值mNeedLeftSpacing=false；
公共项decorationalBumColumns（int-gridSpacingPx，int-gridSize）{
mSizeGridSpacingPx=gridSpacingPx；
mGridSize=gridSize；
}
@凌驾
public void getItemOffsets（Rect outRect、View View、RecyclerView父级、RecyclerView.State）{
int frameWidth=（int）（（parent.getWidth（）-（float）mSizeGridSpacingPx*（mGridSize-1））/mGridSize）；
int padding=parent.getWidth（）/mGridSize-frameWidth；
int itemPosition=（（RecyclerView.LayoutParams）view.getLayoutParams（））.getViewAdapterPosition（）；
if（itemPosition您可能已经得到了答案，但我仍在发布我的解决方案，以帮助其他人。这可以通过传递方向来用于垂直、水平列表或栅格视图
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{
android.R.attr.listDivider
};
public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
public static final int GRID = 2;
private Drawable mDivider;
private int mOrientation;
public DividerItemDecoration(Context context, int orientation) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
setOrientation(orientation);
}
public void setOrientation(int orientation) {
if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST && orientation != GRID) {
throw new IllegalArgumentException("invalid orientation");
}
mOrientation = orientation;
}
@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
if (mOrientation == VERTICAL_LIST) {
drawVertical(c, parent);
} else if(mOrientation == HORIZONTAL_LIST){
drawHorizontal(c, parent);
} else {
drawVertical(c, parent);
drawHorizontal(c, parent);
}
}
public void drawVertical(Canvas c, RecyclerView parent) {
if (parent.getChildCount() == 0) return;
final int left = parent.getPaddingLeft();
final int right = parent.getWidth() - parent.getPaddingRight();
final View child = parent.getChildAt(0);
if (child.getHeight() == 0) return;
final RecyclerView.LayoutParams params =
(RecyclerView.LayoutParams) child.getLayoutParams();
int top = child.getBottom() + params.bottomMargin + mDivider.getIntrinsicHeight();
int bottom = top + mDivider.getIntrinsicHeight();
final int parentBottom = parent.getHeight() - parent.getPaddingBottom();
while (bottom < parentBottom) {
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
top += mDivider.getIntrinsicHeight() + params.topMargin + child.getHeight() + params.bottomMargin + mDivider.getIntrinsicHeight();
bottom = top + mDivider.getIntrinsicHeight();
}
}
public void drawHorizontal(Canvas c, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params =
(RecyclerView.LayoutParams) child.getLayoutParams();
final int left = child.getRight() + params.rightMargin + mDivider.getIntrinsicHeight();
final int right = left + mDivider.getIntrinsicWidth();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
if (mOrientation == VERTICAL_LIST) {
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else if(mOrientation == HORIZONTAL_LIST) {
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
} else {
outRect.set(0, 0, mDivider.getIntrinsicWidth(), mDivider.getIntrinsicHeight());
}
}
}
导入android.content.Context；
导入android.content.res.TypedArray；
导入android.graphics.Canvas；
导入android.graphics.Rect；
导入android.graphics.drawable.drawable；
导入android.support.v7.widget.LinearLayoutManager；
导入android.support.v7.widget.RecyclerView；
导入android.view.view；
公共类DividerItemDecoration扩展了RecyclerView.ItemDecoration{
私有静态最终整数[]属性=新整数[]{
android.R.attr.listDivider
};
public static final int HORIZONTAL_LIST=LinearLayoutManager.HORIZONTAL；
public static final int VERTICAL_LIST=LinearLayoutManager.VERTICAL；
公共静态最终整数网格=2；
专用可抽出式mDivider；
私人托管；
公共DividerItemDecoration（上下文，int方向）{
最终类型Darray a=上下文。获取样式属性（属性）；
mDivider=a.getDrawable（0）；
a、 回收（）；
定向（定向）；
}
公共方向（整数方向）{
如果（方向！=水平列表和方向！=垂直列表和方向！=网格）{
抛出新的IllegalArgumentException（“无效方向”）；
}
朝气=方向；
}
@凌驾
公共void onDrawOver（画布c、RecyclerView父级、RecyclerView.State）{
if（morentation==垂直列表）{
（c）父母；
}else if（Morentation==水平列表）{
水平拉伸（c，母材）；
}否则{
（c）父母；
水平拉伸（c，母材）；
}
}
公共void drawVertical（画布c、回收视图父对象）{
如果（parent.getChildCount（）==0）返回；
final int left=parent.getPaddingLeft（）；
final int right=parent.getWidth（）-parent.getPaddingRight（）；
最终视图子对象=父对象。getChildAt（0）；
如果（child.getHeight（）==0）返回；
最终RecyclerView.LayoutParams参数=
（RecyclerView.LayoutParams）child.getLayoutParams（）；
int top=child.getBottom（）+params.bottomMargin+mDivider.getIntrinsicHeight（）；
int bottom=top+mDivider.getIntrinsicHeight（）；
final int parentBottom=parent.getHeight（）-parent.getPaddingBottom（）；
while（底部<底部）{
mDivider.setBounds（左、上、右、下）；
mDivider.draw（c）；
top+=mDivider.getIntrinsicHeight（）+params.topMargin+child.getHeight（）+params.bottomMargin+mDivider.getIntrinsicHeight（）；
bottom=top+mDivider.getIntrinsicHeight（）；
}
}
公共void drawHorizontal（画布c，回收视图父对象）{
final int top=parent.getPaddingTop（）；
final int bottom=parent.getHeight（）-parent.getPaddingBottom（）；
final int childCount=parent.getChildCount（）；
for（int i=0；iimport android.graphics.Rect;
import android.support.v7.widget.RecyclerView;
import android.view.View;
public class ItemDecorationAlbumColumns extends RecyclerView.ItemDecoration {
private int mSizeGridSpacingPx;
private int mGridSize;
private boolean mNeedLeftSpacing = false;
public ItemDecorationAlbumColumns(int gridSpacingPx, int gridSize) {
mSizeGridSpacingPx = gridSpacingPx;
mGridSize = gridSize;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
int frameWidth = (int) ((parent.getWidth() - (float) mSizeGridSpacingPx * (mGridSize - 1)) / mGridSize);
int padding = parent.getWidth() / mGridSize - frameWidth;
int itemPosition = ((RecyclerView.LayoutParams) view.getLayoutParams()).getViewAdapterPosition();
if (itemPosition < mGridSize) {
outRect.top = 0;
} else {
outRect.top = mSizeGridSpacingPx;
}
if (itemPosition % mGridSize == 0) {
outRect.left = 0;
outRect.right = padding;
mNeedLeftSpacing = true;
} else if ((itemPosition + 1) % mGridSize == 0) {
mNeedLeftSpacing = false;
outRect.right = 0;
outRect.left = padding;
} else if (mNeedLeftSpacing) {
mNeedLeftSpacing = false;
outRect.left = mSizeGridSpacingPx - padding;
if ((itemPosition + 2) % mGridSize == 0) {
outRect.right = mSizeGridSpacingPx - padding;
} else {
outRect.right = mSizeGridSpacingPx / 2;
}
} else if ((itemPosition + 2) % mGridSize == 0) {
mNeedLeftSpacing = false;
outRect.left = mSizeGridSpacingPx / 2;
outRect.right = mSizeGridSpacingPx - padding;
} else {
mNeedLeftSpacing = false;
outRect.left = mSizeGridSpacingPx / 2;
outRect.right = mSizeGridSpacingPx / 2;
}
outRect.bottom = 0;
}
}
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{
android.R.attr.listDivider
};
public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
public static final int GRID = 2;
private Drawable mDivider;
private int mOrientation;
public DividerItemDecoration(Context context, int orientation) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
setOrientation(orientation);
}
public void setOrientation(int orientation) {
if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST && orientation != GRID) {
throw new IllegalArgumentException("invalid orientation");
}
mOrientation = orientation;
}
@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
if (mOrientation == VERTICAL_LIST) {
drawVertical(c, parent);
} else if(mOrientation == HORIZONTAL_LIST){
drawHorizontal(c, parent);
} else {
drawVertical(c, parent);
drawHorizontal(c, parent);
}
}
public void drawVertical(Canvas c, RecyclerView parent) {
if (parent.getChildCount() == 0) return;
final int left = parent.getPaddingLeft();
final int right = parent.getWidth() - parent.getPaddingRight();
final View child = parent.getChildAt(0);
if (child.getHeight() == 0) return;
final RecyclerView.LayoutParams params =
(RecyclerView.LayoutParams) child.getLayoutParams();
int top = child.getBottom() + params.bottomMargin + mDivider.getIntrinsicHeight();
int bottom = top + mDivider.getIntrinsicHeight();
final int parentBottom = parent.getHeight() - parent.getPaddingBottom();
while (bottom < parentBottom) {
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
top += mDivider.getIntrinsicHeight() + params.topMargin + child.getHeight() + params.bottomMargin + mDivider.getIntrinsicHeight();
bottom = top + mDivider.getIntrinsicHeight();
}
}
public void drawHorizontal(Canvas c, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params =
(RecyclerView.LayoutParams) child.getLayoutParams();
final int left = child.getRight() + params.rightMargin + mDivider.getIntrinsicHeight();
final int right = left + mDivider.getIntrinsicWidth();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
if (mOrientation == VERTICAL_LIST) {
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else if(mOrientation == HORIZONTAL_LIST) {
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
} else {
outRect.set(0, 0, mDivider.getIntrinsicWidth(), mDivider.getIntrinsicHeight());
}
}
}
@BindingAdapter({"bind:adapter"})
public static void bind(RecyclerView view, RecyclerView.Adapter<BaseViewHolder> adapter) {
view.setLayoutManager(new GridLayoutManager(view.getContext(), 3));
view.addItemDecoration(new SpacesItemDecorationGrid(view.getContext(), 4, 3));
view.setItemAnimator(new DefaultItemAnimator());
view.setAdapter(adapter);
}
public class SpacesItemDecorationGrid extends RecyclerView.ItemDecoration {
private int mSizeGridSpacingPx;
private int mGridSize;
private boolean mNeedLeftSpacing = false;
/**
* @param gridSpacingPx
* @param gridSize
*/
SpacesItemDecorationGrid(Context context, int gridSpacingPx, int gridSize) {
mSizeGridSpacingPx = (int) Util.convertDpToPixel(gridSpacingPx, context);
mGridSize = gridSize;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
int frameWidth = (int) ((parent.getWidth() - (float) mSizeGridSpacingPx * (mGridSize - 1)) / mGridSize);
int padding = parent.getWidth() / mGridSize - frameWidth;
int itemPosition = ((RecyclerView.LayoutParams) view.getLayoutParams()).getViewAdapterPosition();
int itemCount = parent.getAdapter().getItemCount() - mGridSize;
/* if (itemPosition < mGridSize) {
outRect.top = mSizeGridSpacingPx;
} else {
outRect.top = mSizeGridSpacingPx;
}*/
outRect.top = mSizeGridSpacingPx;
if (itemPosition % mGridSize == 0) {
outRect.left = mSizeGridSpacingPx;
outRect.right = padding;
mNeedLeftSpacing = true;
} else if ((itemPosition + 1) % mGridSize == 0) {
mNeedLeftSpacing = false;
outRect.right = mSizeGridSpacingPx;
outRect.left = padding;
} else if (mNeedLeftSpacing) {
mNeedLeftSpacing = false;
outRect.left = mSizeGridSpacingPx - padding;
if ((itemPosition + 2) % mGridSize == 0) {
outRect.right = mSizeGridSpacingPx - padding;
} else {
outRect.right = mSizeGridSpacingPx / 2;
}
} else if ((itemPosition + 2) % mGridSize == 0) {
mNeedLeftSpacing = false;
outRect.left = mSizeGridSpacingPx / 2;
outRect.right = mSizeGridSpacingPx - padding;
} else {
mNeedLeftSpacing = false;
outRect.left = mSizeGridSpacingPx / 2;
outRect.right = mSizeGridSpacingPx / 2;
}
if (itemPosition > itemCount) {
outRect.bottom = mSizeGridSpacingPx;
} else {
outRect.bottom = 0;
}
}
}
class GridItemDecorator(val context: Context, private val spacingDp: Int, private val mGridSize: Int) : RecyclerView.ItemDecoration() {
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
val resources = context.resources
val spacingPx = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, spacingDp.toFloat(), resources.displayMetrics)
val bit = if (spacingPx > mGridSize) Math.round(spacingPx / mGridSize) else 1
val itemPosition = (view.layoutParams as RecyclerView.LayoutParams).viewAdapterPosition
outRect.top = if (itemPosition < mGridSize) 0 else bit * mGridSize
outRect.bottom = 0
val rowPosition = itemPosition % mGridSize
outRect.left = rowPosition * bit
outRect.right = (mGridSize - rowPosition - 1) * bit
}
}
public class MediaSpaceDecoration extends RecyclerView.ItemDecoration {
private final int spacing;
private final List<Integer> allowedViewTypes = Arrays.asList(
R.layout.item_image,
R.layout.item_blur);
public MediaSpaceDecoration(int spacing) {
this.spacing = spacing;
}
@Override
public void getItemOffsets(Rect outRect,
View view,
RecyclerView parent,
RecyclerView.State state) {
final int position = parent.getChildAdapterPosition(view);
if (!isMedia(parent, position)) {
return;
}
final int totalSpanCount = getTotalSpanCount(parent);
int spanSize = getItemSpanSize(parent, position);
if (totalSpanCount == spanSize) {
return;
}
outRect.top = isInTheFirstRow(position, totalSpanCount) ? 0 : spacing;
outRect.left = isFirstInRow(position, totalSpanCount) ? 0 : spacing / 2;
outRect.right = isLastInRow(position, totalSpanCount) ? 0 : spacing / 2;
outRect.bottom = 0; // don't need
}
private boolean isInTheFirstRow(int position, int spanCount) {
return position < spanCount;
}
private boolean isFirstInRow(int position, int spanCount) {
return position % spanCount == 0;
}
private boolean isLastInRow(int position, int spanCount) {
return isFirstInRow(position + 1, spanCount);
}
private int getTotalSpanCount(RecyclerView parent) {
final RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
return layoutManager instanceof GridLayoutManager
? ((GridLayoutManager) layoutManager).getSpanCount()
: 1;
}
private int getItemSpanSize(RecyclerView parent, int position) {
final RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
return layoutManager instanceof GridLayoutManager
? ((GridLayoutManager) layoutManager).getSpanSizeLookup().getSpanSize(position)
: 1;
}
private boolean isMedia(RecyclerView parent, int viewPosition) {
final RecyclerView.Adapter adapter = parent.getAdapter();
final int viewType = adapter.getItemViewType(viewPosition);
return allowedViewTypes.contains(viewType);
}
}
import android.graphics.Rect
import android.view.View
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.RecyclerView
class GridDividerItemDecoration(private val spacing: Int) : RecyclerView.ItemDecoration() {
override fun getItemOffsets(
outRect: Rect,
view: View,
parent: RecyclerView,
state: RecyclerView.State
) {
val position = parent.getChildAdapterPosition(view)
val totalSpanCount = getTotalSpanCount(parent)
val spanSize = getItemSpanSize(parent, position)
outRect.top = if (isInTheFirstRow(position, totalSpanCount)) 0 else spacing
outRect.left = if (isFirstInRow(position, totalSpanCount, spanSize)) 0 else spacing / 2
outRect.right = if (isLastInRow(position, totalSpanCount, spanSize)) 0 else spacing / 2
outRect.bottom = 0
}
private fun isInTheFirstRow(position: Int, totalSpanCount: Int): Boolean =
position < totalSpanCount
private fun isFirstInRow(position: Int, totalSpanCount: Int, spanSize: Int): Boolean =
if (totalSpanCount != spanSize) {
position % totalSpanCount == 0
} else true
private fun isLastInRow(position: Int, totalSpanCount: Int, spanSize: Int): Boolean =
isFirstInRow(position + 1, totalSpanCount, spanSize)
private fun getTotalSpanCount(parent: RecyclerView): Int =
(parent.layoutManager as? GridLayoutManager)?.spanCount ?: 1
private fun getItemSpanSize(parent: RecyclerView, position: Int): Int =
(parent.layoutManager as? GridLayoutManager)?.spanSizeLookup?.getSpanSize(position) ?: 1
}
class GridItemOffsetDecoration(private val spanCount: Int, private var mItemOffset: Int) : ItemDecoration() {
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView,
state: RecyclerView.State) {
val position = parent.getChildAdapterPosition(view)
if (position < spanCount) {
if (position % 2 == 0) { // left grid
outRect.set(0, mItemOffset, mItemOffset / 2, mItemOffset / 2)
} else { // right grid
outRect.set(mItemOffset / 2, mItemOffset, 0, mItemOffset / 2)
}
} else if (position % 2 == 0) { // left grid
outRect.set(0, mItemOffset / 2, mItemOffset, mItemOffset / 2)
} else if (position % 2 == 1) { // right grid
outRect.set(mItemOffset / 2, mItemOffset / 2, 0, mItemOffset / 2)
} else {
if (position % 2 == 0) { // left grid
outRect.set(0, mItemOffset / 2, mItemOffset, mItemOffset)
} else { // right grid
outRect.set(mItemOffset / 2, mItemOffset / 2, 0, mItemOffset)
}
}
}
/*spanCount is the number of grids, for instance, (2 = 2*2 grid, 3 = 3*3)*/
binding.rvActiveChallenges.addItemDecoration(GridItemOffsetDecoration(2, resources.getDimensionPixelSize(R.dimen._10dp)))