androidx.recyclerview.widget.RecyclerView#getChildAt ( )源码实例Demo

下面列出了androidx.recyclerview.widget.RecyclerView#getChildAt ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。

源代码1 项目： RecyclerViewExtensions 文件： DividerItemDecoration.java

public void drawVertical(Canvas canvas, RecyclerView parent) {
    int left = parent.getPaddingLeft();
    int right = parent.getWidth() - parent.getPaddingRight();

    final int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        View child = parent.getChildAt(i);
        if (!hasDivider(parent, child)) {
            continue;
        }

        if (mDrawable.isStateful()) {
            mDrawable.setState(child.getDrawableState());
        }

        RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
        int top = child.getBottom() + params.bottomMargin + Math.round(child.getTranslationY());
        int bottom = top + mDrawable.getIntrinsicHeight();
        drawDivider(canvas, left, top, right, bottom, child.getAlpha());
    }
}

源代码2 项目： bcm-android 文件： StickyHeaderDecoration.java

/**
 * {@inheritDoc}
 */
@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
    final int count = parent.getChildCount();

    for (int layoutPos = 0; layoutPos < count; layoutPos++) {
        final View child = parent.getChildAt(translatedChildPosition(parent, layoutPos));

        final int adapterPos = parent.getChildAdapterPosition(child);

        if (adapterPos != RecyclerView.NO_POSITION && ((layoutPos == 0 && sticky) || hasHeader(parent, adapter, adapterPos))) {
            View header = getHeader(parent, adapter, adapterPos).itemView;
            c.save();
            final int left = child.getLeft();
            final int top = getHeaderTop(parent, child, header, adapterPos, layoutPos);
            c.translate(left, top);
            header.draw(c);
            c.restore();
        }
    }
}

源代码3 项目： material-components-android 文件： GridDividerDecoration.java

private void drawVertical(Canvas canvas, RecyclerView parent) {
  final int childCount = parent.getChildCount();
  final boolean isRTL =
      ViewCompat.getLayoutDirection(parent) == ViewCompat.LAYOUT_DIRECTION_RTL;
  for (int i = 0; i < childCount; i++) {
    final View child = parent.getChildAt(i);

    if (isChildInLastColumn(parent, child)) {
      continue;
    }

    parent.getDecoratedBoundsWithMargins(child, bounds);
    final int x = isRTL ? bounds.left : bounds.right;
    final int startY = bounds.top;
    final int stopY = bounds.bottom;
    canvas.drawLine(x, startY, x, stopY, dividerPaint);
  }
}

源代码4 项目： green_android 文件： DividerItem.java

@Override
public void onDrawOver(final Canvas c, final RecyclerView parent,
                       final RecyclerView.State state) {
    final int left = parent.getPaddingLeft();
    final int right = parent.getWidth() - parent.getPaddingRight();

    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 top = child.getBottom() + params.bottomMargin;
        final int bottom = top + divider.getIntrinsicHeight();

        divider.setBounds(left, top, right, bottom);
        divider.draw(c);
    }
}

源代码5 项目： NewFastFrame 文件： ListViewDecoration.java

@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
    if (divider != null) {
        int count = parent.getChildCount();
        int left = parent.getPaddingLeft();
        int right = parent.getWidth() - parent.getPaddingRight();
        View child = null;
        for (int i = 0; i < count; i++) {
            if (count == 1) {
                break;
            }
            child = parent.getChildAt(i);
            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            int top = child.getBottom() + params.bottomMargin;
            int bottom = top + divider.getIntrinsicHeight();
            divider.setBounds(left, top, right, bottom);
            divider.draw(c);
        }
    }
}

源代码6 项目： Telegram 文件： GroupCreateDividerItemDecoration.java

@Override
public void onDraw(Canvas canvas, RecyclerView parent, RecyclerView.State state) {
    int width = parent.getWidth();
    int top;
    int childCount = parent.getChildCount() - (single ? 0 : 1);
    for (int i = 0; i < childCount; i++) {
        View child = parent.getChildAt(i);
        View nextChild = i < childCount - 1 ? parent.getChildAt(i + 1) : null;
        int position = parent.getChildAdapterPosition(child);
        if (position < skipRows || child instanceof GroupCreateSectionCell || nextChild instanceof GroupCreateSectionCell) {
            continue;
        }
        top = child.getBottom();
        canvas.drawLine(LocaleController.isRTL ? 0 : AndroidUtilities.dp(72), top, width - (LocaleController.isRTL ? AndroidUtilities.dp(72) : 0), top, Theme.dividerPaint);
    }
}

源代码7 项目： MyBookshelf 文件： DividerGridItemDecoration.java

public void drawHorizontal(Canvas c, RecyclerView parent) {
    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.getLeft() - params.leftMargin;
        final int right = child.getRight() + params.rightMargin
                + mWidthDivider.getIntrinsicWidth();
        final int top = child.getBottom() + params.bottomMargin;
        final int bottom = top + mWidthDivider.getIntrinsicHeight();
        mWidthDivider.setBounds(left, top, right, bottom);
        mWidthDivider.draw(c);
    }


}

源代码8 项目： Ruisi 文件： MyGridDivider.java

@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {

    int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = parent.getChildAt(i);
        final int left = child.getLeft();
        final int right = child.getRight();
        final int top = child.getTop();
        final int bottom = child.getBottom();
        c.drawRect(left + devideWidth / 2, top + devideWidth / 2, right - devideWidth / 2, bottom - devideWidth / 2, maint);
    }
}

源代码9 项目： bcm-android 文件： StickyHeaderDecoration.java

protected int getHeaderTop(RecyclerView parent, View child, View header, int adapterPos,
                           int layoutPos) {
    int headerHeight = getHeaderHeightForLayout(header);
    int top = getChildY(parent, child) - headerHeight;
    if (sticky && layoutPos == 0) {
        final int count = parent.getChildCount();
        final long currentId = adapter.getHeaderId(adapterPos);
        // find next view with header and compute the offscreen push if needed
        for (int i = 1; i < count; i++) {
            int adapterPosHere = parent.getChildAdapterPosition(parent.getChildAt(translatedChildPosition(parent, i)));
            if (adapterPosHere != RecyclerView.NO_POSITION) {
                long nextId = adapter.getHeaderId(adapterPosHere);
                if (nextId != currentId) {
                    final View next = parent.getChildAt(translatedChildPosition(parent, i));
                    final int offset = getChildY(parent, next) - (headerHeight + getHeader(parent, adapter, adapterPosHere).itemView.getHeight());
                    if (offset < 0) {
                        return offset;
                    } else {
                        break;
                    }
                }
            }
        }

        if (sticky) {
            top = Math.max(0, top);
        }
    }

    return top;
}

源代码10 项目： CommonUtils 文件： SelectiveDividerItemDecoration.java

private void drawVertical(Canvas canvas, RecyclerView parent) {
    canvas.save();

    int left;
    int right;
    if (parent.getClipToPadding()) {
        left = parent.getPaddingLeft();
        right = parent.getWidth() - parent.getPaddingRight();
        canvas.clipRect(left, parent.getPaddingTop(), right, parent.getHeight() - parent.getPaddingBottom());
    } else {
        left = 0;
        right = parent.getWidth();
    }

    int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        if (isDecorated(i)) {
            View child = parent.getChildAt(i);
            parent.getDecoratedBoundsWithMargins(child, mBounds);
            int bottom = mBounds.bottom + Math.round(child.getTranslationY());
            int top = bottom - mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(canvas);
        }
    }

    canvas.restore();
}

源代码11 项目： a 文件： SimpleDividerDecoration.java

@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
    int childCount = parent.getChildCount();
    int left = parent.getPaddingLeft();
    int right = parent.getWidth() - parent.getPaddingRight();

    for (int i = 0; i < childCount - 1; i++) {
        View view = parent.getChildAt(i);
        float top = view.getBottom();
        float bottom = view.getBottom() + dividerHeight;
        c.drawRect(left, top, right, bottom, dividerPaint);
    }
}

源代码12 项目： header-decor 文件： DoubleHeaderDecoration.java

private int getSubHeaderTop(@NonNull RecyclerView parent, @NonNull View child,
        @NonNull View header, @NonNull View subHeader, int adapterPos, int layoutPos) {

    int top = getAnimatedTop(child) - getSubHeaderHeightForLayout(subHeader);
    if (isFirstValidChild(layoutPos, parent)) {
        final int count = parent.getChildCount();
        final long currentHeaderId = adapter.getHeaderId(adapterPos);
        final long currentSubHeaderId = adapter.getSubHeaderId(adapterPos);

        // find next view with sub-header and compute the offscreen push if needed
        for (int i = layoutPos + 1; i < count; i++) {
            final View next = parent.getChildAt(i);
            int adapterPosHere = parent.getChildAdapterPosition(next);
            if (adapterPosHere != RecyclerView.NO_POSITION) {
                final long nextHeaderId = adapter.getHeaderId(adapterPosHere);
                final long nextSubHeaderId = adapter.getSubHeaderId(adapterPosHere);

                if ((nextSubHeaderId != currentSubHeaderId)) {
                    int headersHeight = getSubHeaderHeightForLayout(subHeader) +
                            getSubHeader(parent, adapterPosHere).itemView.getHeight();
                    if (nextHeaderId != currentHeaderId) {
                        headersHeight += getHeader(parent, adapterPosHere).itemView.getHeight();
                    }

                    final int offset = getAnimatedTop(next) - headersHeight;
                    if (offset < header.getHeight()) {
                        return offset;
                    } else {
                        break;
                    }
                }
            }
        }
    }

    return Math.max(header.getHeight(), top);
}

源代码13 项目： SAI 文件： InstallerXAdapterDividerItemDecoration.java

private void drawVertical(Canvas canvas, RecyclerView parent) {
    canvas.save();
    final int left;
    final int right;
    //noinspection AndroidLintNewApi - NewApi lint fails to handle overrides.
    if (parent.getClipToPadding()) {
        left = parent.getPaddingLeft();
        right = parent.getWidth() - parent.getPaddingRight();
        canvas.clipRect(left, parent.getPaddingTop(), right,
                parent.getHeight() - parent.getPaddingBottom());
    } else {
        left = 0;
        right = parent.getWidth();
    }

    final int childCount = parent.getChildCount();
    RecyclerView.Adapter adapter = parent.getAdapter();
    final int itemCount = adapter == null ? -1 : adapter.getItemCount();
    for (int i = 0; i < childCount; i++) {
        final View child = parent.getChildAt(i);
        int adapterPosition = parent.getChildAdapterPosition(child);
        if (adapterPosition == 0 || adapterPosition == itemCount - 1)
            continue;

        parent.getDecoratedBoundsWithMargins(child, mBounds);
        final int bottom = mBounds.bottom + Math.round(child.getTranslationY());
        final int top = bottom - mDivider.getIntrinsicHeight();
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(canvas);
    }
    canvas.restore();
}

源代码14 项目： MVPArms 文件： DefaultAdapter.java

/**
 * 遍历所有 {@link BaseHolder}, 释放他们需要释放的资源
 *
 * @param recyclerView {@link RecyclerView}
 */
public static void releaseAllHolder(RecyclerView recyclerView) {
    if (recyclerView == null) {
        return;
    }
    for (int i = recyclerView.getChildCount() - 1; i >= 0; i--) {
        final View view = recyclerView.getChildAt(i);
        RecyclerView.ViewHolder viewHolder = recyclerView.getChildViewHolder(view);
        if (viewHolder instanceof BaseHolder) {
            ((BaseHolder) viewHolder).onRelease();
        }
    }
}

源代码15 项目： monero-wallet-android-app 文件： DividerItemDecoration.java

private void drawVertical(Canvas canvas, RecyclerView parent) {
    canvas.save();
    final int left;
    final int right;
    //noinspection AndroidLintNewApi - NewApi lint fails to handle overrides.
    if (parent.getClipToPadding()) {
        left = parent.getPaddingLeft();
        right = parent.getWidth() - parent.getPaddingRight();
        canvas.clipRect(left, parent.getPaddingTop(), right,
                parent.getHeight() - parent.getPaddingBottom());
    } else {
        left = 0;
        right = parent.getWidth();
    }

    final int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = parent.getChildAt(i);
        parent.getDecoratedBoundsWithMargins(child, mBounds);
        final int bottom = mBounds.bottom + Math.round(child.getTranslationY());
        final int top = bottom - mDividerSize;
        mDividerPaint.setColor(mDividerColor);
        mDividerPaint.setStyle(Paint.Style.FILL);
        canvas.drawRect(left + mMarginStart, top + mMarginTop, right - mMarginEnd, bottom - mMarginBottom, mDividerPaint);
    }
    canvas.restore();
}

源代码16 项目： aptoide-client-v8 文件： DrawableItemDecoration.java

@Override public void onDrawOver(Canvas canvas, RecyclerView parent, RecyclerView.State state) {
  final int left = /* parent.getPaddingLeft() + */ customHorizontalPadding;
  final int right = parent.getWidth() /* - parent.getPaddingRight() */ - customHorizontalPadding;

  final int childCount = parent.getChildCount();
  for (int i = 0; i < (childCount - 1); i++) {
    final View child = parent.getChildAt(i);
    final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
    final int top = child.getBottom() + params.bottomMargin;
    final int bottom = top + dividerDrawable.getIntrinsicHeight();
    dividerDrawable.setBounds(left, top, right, bottom);
    dividerDrawable.draw(canvas);
  }
}

源代码17 项目： RecyclerViewHelper 文件： SuperDividerItemDecoration.java

/**
 * Draw a horizontal line.
 *
 * @param canvas Canvas
 * @param parent RecyclerView
 */
private void drawHorizontalLine(Canvas canvas, RecyclerView parent) {
    RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
    if (layoutManager == null || mDivider == null) {
        return;
    }

    canvas.save();
    final int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = parent.getChildAt(i);
        if (isLastRow(child, parent)) {
            continue;
        }

        parent.getDecoratedBoundsWithMargins(child, mBounds);
        final int left = mBounds.left;
        final int right = mBounds.right;
        int bottom = mBounds.bottom + Math.round(child.getTranslationY());
        // Horizontal GridLayout display in the left, margin top or bottom mDividerHeight / 2.
        if (mOrientation == HORIZONTAL && layoutManager instanceof GridLayoutManager) {
            bottom += mDividerHeight / 2;
        }
        final int top = bottom - mDividerHeight;
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(canvas);
    }
    canvas.restore();
}

源代码18 项目： shinny-futures-android 文件： DividerGridItemDecorationUtils.java

private void drawHorizontal(Canvas c, RecyclerView parent) {
    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.getLeft() - params.leftMargin;
        final int right = child.getRight() + params.rightMargin
                + mDivider.getIntrinsicWidth();
        final int top = child.getBottom() + params.bottomMargin;
        final int bottom = top + mDivider.getIntrinsicHeight();
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(c);
    }
}

源代码19 项目： Telegram-FOSS 文件： MediaActivity.java

private void updateSections(RecyclerView listView, boolean checkTopBottom) {
    int count = listView.getChildCount();
    int minPositionDateHolder = Integer.MAX_VALUE;
    View minDateChild = null;
    float padding = listView.getPaddingTop() + actionBar.getTranslationY();
    int minTop = Integer.MAX_VALUE;
    int maxBottom = 0;

    for (int a = 0; a < count; a++) {
        View view = listView.getChildAt(a);
        int bottom = view.getBottom();
        minTop = Math.min(minTop, view.getTop());
        maxBottom = Math.max(bottom, maxBottom);
        if (bottom <= padding) {
            continue;
        }
        int position = view.getBottom();
        if (view instanceof SharedMediaSectionCell || view instanceof GraySectionCell) {
            if (view.getAlpha() != 1.0f) {
                view.setAlpha(1.0f);
            }
            if (position < minPositionDateHolder) {
                minPositionDateHolder = position;
                minDateChild = view;
            }
        }
    }
    if (minDateChild != null) {
        if (minDateChild.getTop() > padding) {
            if (minDateChild.getAlpha() != 1.0f) {
                minDateChild.setAlpha(1.0f);
            }
        } else {
            if (minDateChild.getAlpha() != 0.0f) {
                minDateChild.setAlpha(0.0f);
            }
        }
    }
    if (checkTopBottom) {
        if (maxBottom != 0 && maxBottom < (listView.getMeasuredHeight() - listView.getPaddingBottom())) {
            resetScroll();
        } else if (minTop != Integer.MAX_VALUE && minTop > listView.getPaddingTop() + actionBar.getTranslationY()) {
            scrollWithoutActionBar(listView, -listView.computeVerticalScrollOffset());
            resetScroll();
        }
    }
}

源代码20 项目： MyBookshelf 文件： GridSpacingItemDecoration.java

/***/
private void drawGrideview1(Canvas canvas, RecyclerView parent) {
    GridLayoutManager linearLayoutManager = (GridLayoutManager) parent.getLayoutManager();
    int childSize = parent.getChildCount();
    int top, bottom, left, right, spancount;
    spancount = linearLayoutManager.getSpanCount();
    for (int i = 0; i < childSize; i++) {
        final View child = parent.getChildAt(i);
        //画横线
        RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
        top = child.getBottom() + layoutParams.bottomMargin;
        bottom = top + space;
        left = layoutParams.leftMargin + child.getPaddingLeft() + space;
        right = child.getMeasuredWidth() * (i + 1) + left + space * i;
        if (mDivider != null) {
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(canvas);
        }
        if (mPaint != null) {
            canvas.drawRect(left, top, right, bottom, mPaint);
        }
        //画竖线
        top = (layoutParams.topMargin + space) * (i / linearLayoutManager.getSpanCount() + 1);
        bottom = (child.getMeasuredHeight() + space) * (i / linearLayoutManager.getSpanCount() + 1) + space;
        left = child.getRight() + layoutParams.rightMargin;
        right = left + space;
        if (mDivider != null) {
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(canvas);
        }
        if (mPaint != null) {
            canvas.drawRect(left, top, right, bottom, mPaint);
        }

        //画上缺失的线框
        if (i < spancount) {
            top = child.getTop() + layoutParams.topMargin;
            bottom = top + space;
            left = (layoutParams.leftMargin + space) * (i + 1);
            right = child.getMeasuredWidth() * (i + 1) + left + space * i;
            if (mDivider != null) {
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(canvas);
            }
            if (mPaint != null) {
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
        if (i % spancount == 0) {
            top = (layoutParams.topMargin + space) * (i / linearLayoutManager.getSpanCount() + 1);
            bottom = (child.getMeasuredHeight() + space) * (i / linearLayoutManager.getSpanCount() + 1) + space;
            left = child.getLeft() + layoutParams.leftMargin;
            right = left + space;
            if (mDivider != null) {
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(canvas);
            }
            if (mPaint != null) {
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
    }
}

方法所在类

androidx.recyclerview.widget.RecyclerView