解决RecycleView分割线不居中的三种方法
陶淳
本文向大家介绍解决RecycleView分割线不居中的三种方法，包括了解决RecycleView分割线不居中的三种方法的使用技巧和注意事项，需要的朋友参考一下
本文为大家分享了三种RecycleView分割线不居中的解决方法，供大家参考，具体内容和如下
方法一：
public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
private int mSpace;
private int mSpanCount; // RecyclerView有多少列
private boolean mHasPadding; // RecyclerView是否有Padding
public SpacesItemDecoration(int mSpace) {
this.mSpace = mSpace;
this.mHasPadding = true;
}
public SpacesItemDecoration(int mSpace, boolean hasPadding) {
this.mSpace = mSpace;
this.mHasPadding = hasPadding;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
// 初始化列数
if (mSpanCount == 0) {
this.mSpanCount = ((GridLayoutManager) parent.getLayoutManager()).getSpanCount();
}
int position = parent.getChildAdapterPosition(view); // item position
int column = position % mSpanCount; // item column
if (mHasPadding) {
outRect.left = mSpace - column * mSpace / mSpanCount; // spacing - column * ((1f / spanCount) * spacing)
outRect.right = (column + 1) * mSpace / mSpanCount; // (column + 1) * ((1f / spanCount) * spacing)
if (position < mSpanCount) { // top edge
outRect.top = mSpace;
}
outRect.bottom = mSpace; // item bottom
} else {
outRect.left = column * mSpace / mSpanCount; // column * ((1f / spanCount) * spacing)
outRect.right = mSpace - (column + 1) * mSpace / mSpanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
if (position >= mSpanCount) {
outRect.top = mSpace; // item top
}
}
}
public void setHasPadding(boolean hasPadding) {
this.mHasPadding = hasPadding;
}
}
方法二：
public class MutiItemDecoration extends RecyclerView.ItemDecoration {
public enum Type {
VERTICAL, HORIZONTAL, ALL
}
private Type type;//分割线类型
private int dividerSize = 10;//分割线尺寸
public MutiItemDecoration(MutiItemDecoration.Type type, int dividerSize) {
this.type = type;
this.dividerSize = dividerSize;
}
@Override
public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
int spanCount = getSpanCount(parent);
int childCount = parent.getAdapter().getItemCount();
switch (type) {
case ALL:
if (itemPosition % spanCount == 0) {//第一列
if (isLastRaw(parent, itemPosition, spanCount, childCount)) {
outRect.set(0, 0, dividerSize / 2, 0);
} else {
outRect.set(0, 0, dividerSize / 2, dividerSize);
}
} else if (itemPosition % spanCount == spanCount - 1) {//最后一列
if (isLastRaw(parent, itemPosition, spanCount, childCount)) {
outRect.set(dividerSize / 2, 0, 0, 0);
} else {
outRect.set(dividerSize / 2, 0, 0, dividerSize);
}
} else {//中间列
if (isLastRaw(parent, itemPosition, spanCount, childCount)) {
outRect.set(dividerSize / 2, 0, dividerSize / 2, 0);
} else {
outRect.set(dividerSize / 2, 0, dividerSize / 2, dividerSize);
}
}
break;
case VERTICAL:
if (isLastRaw(parent, itemPosition, spanCount, childCount)) {
outRect.set(0, 0, 0, 0);
} else {
outRect.set(0, 0, 0, dividerSize);
}
break;
case HORIZONTAL:
if (isLastColum(parent, itemPosition, spanCount, childCount)) {
outRect.set(0, 0, 0, 0);
} else {
outRect.set(0, 0, dividerSize, 0);
}
break;
}
}
// 是否是最后一列
private boolean isLastColum(RecyclerView parent, int pos, int spanCount, int childCount) {
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
if ((pos + 1) % spanCount == 0)
return true;
} else {
if (pos == childCount - 1)
return true;
}
return false;
}
// 是否是最后一行
private boolean isLastRaw(RecyclerView parent, int pos, int spanCount, int childCount) {
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
childCount = childCount - childCount % spanCount;
if (pos >= childCount)
return true;
} else {
if (pos == childCount - 1)
return true;
}
return false;
}
//返回列数
private int getSpanCount(RecyclerView parent) {
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
return ((GridLayoutManager) layoutManager).getSpanCount();
}
return -1;
}
}
方法三：（目前只支持2列）
public class DividerGridItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
private Drawable mDivider;
public DividerGridItemDecoration(Context context) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = ContextCompat.getDrawable(context, R.drawable.shape_divider);
a.recycle();
}
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
drawHorizontal(c, parent);
drawVertical(c, parent);
}
private int getSpanCount(RecyclerView parent) {
// 列数
int spanCount = -1;
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
spanCount = ((GridLayoutManager) layoutManager).getSpanCount();
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
spanCount = ((StaggeredGridLayoutManager) layoutManager)
.getSpanCount();
}
return spanCount;
}
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
+ mDivider.getIntrinsicWidth();
final int top = child.getBottom() + params.bottomMargin;
final int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
public void drawVertical(Canvas c, RecyclerView parent) {
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();
if (i % 2 == 1) {
final int top = child.getTop() - params.topMargin;
final int bottom = child.getBottom() + params.bottomMargin;
final int left = child.getLeft() - params.rightMargin;
final int right = left + mDivider.getIntrinsicWidth() / 2;
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
} else {
final int top = child.getTop() - params.topMargin;
final int bottom = child.getBottom() + params.bottomMargin;
final int left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicWidth() / 2;
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
final int top = child.getTop() - params.topMargin;
final int bottom = child.getBottom() + params.bottomMargin;
final int left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicWidth();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
private boolean isLastColum(RecyclerView parent, int pos, int spanCount,
int childCount) {
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
if ((pos + 1) % spanCount == 0)// 如果是最后一列，则不需要绘制右边
{
return true;
}
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation();
if (orientation == StaggeredGridLayoutManager.VERTICAL) {
if ((pos + 1) % spanCount == 0)// 如果是最后一列，则不需要绘制右边
{
return true;
}
} else {
childCount = childCount - childCount % spanCount;
if (pos >= childCount)// 如果是最后一列，则不需要绘制右边
return true;
}
}
return false;
}
private boolean isLastRaw(RecyclerView parent, int pos, int spanCount,
int childCount) {
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
childCount = childCount - childCount % spanCount;
if (pos >= childCount)// 如果是最后一行，则不需要绘制底部
return true;
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation();
// StaggeredGridLayoutManager 且纵向滚动
if (orientation == StaggeredGridLayoutManager.VERTICAL) {
childCount = childCount - childCount % spanCount;
// 如果是最后一行，则不需要绘制底部
if (pos >= childCount)
return true;
} else
// StaggeredGridLayoutManager 且横向滚动
{
// 如果是最后一行，则不需要绘制底部
if ((pos + 1) % spanCount == 0) {
return true;
}
}
}
return false;
}
@Override
public void getItemOffsets(Rect outRect, int itemPosition,
RecyclerView parent) {
int spanCount = getSpanCount(parent);
int childCount = parent.getAdapter().getItemCount();
if (isLastRaw(parent, itemPosition, spanCount, childCount))// 如果是最后一行，则不需要绘制底部
{
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
} else if (isLastColum(parent, itemPosition, spanCount, childCount))// 如果是最后一列，则不需要绘制右边
{
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else {
outRect.set(0, 0, mDivider.getIntrinsicWidth(),
mDivider.getIntrinsicHeight());
}
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持小牛知识库。
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