RecyclerView的萬能分割線

什麼是RecyclerView

RecyclerView是Android 5.0 materials design中的組件之一，相應的還有CardView、Palette等。看名字我們就能看出一點端倪，沒錯，它主要的特點就是復用。我們知道，Listview中的Adapter中可以實現ViewHolder的復用。RecyclerView提供了一個耦合度更低的方式來復用ViewHolder，並且可以輕松的實現ListView、GridView以及瀑布流的效果。

先給大家展示下效果圖：

使用方法：

添加默認分割線：高度為2px，顏色為灰色

mRecyclerView.addItemDecoration(new RecycleViewDivider(mContext, LinearLayoutManager.VERTICAL));

添加自定義分割線：可自定義分割線drawable

mRecyclerView.addItemDecoration(new RecycleViewDivider(
mContext, LinearLayoutManager.VERTICAL, R.drawable.divider_mileage));

添加自定義分割線：可自定義分割線高度和顏色

mRecyclerView.addItemDecoration(new RecycleViewDivider(
mContext, LinearLayoutManager.VERTICAL, 10, getResources().getColor(R.color.divide_gray_color)));

萬能分割線登場：

public class RecycleViewDivider extends RecyclerView.ItemDecoration {
private Paint mPaint;
private Drawable mDivider;
private int mDividerHeight = 2;//分割線高度，默認為1px
private int mOrientation;//列表的方向：LinearLayoutManager.VERTICAL或LinearLayoutManager.HORIZONTAL
private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
/**
* 默認分割線：高度為2px，顏色為灰色
*
* @param context
* @param orientation 列表方向
*/
public RecycleViewDivider(Context context, int orientation) {
if (orientation != LinearLayoutManager.VERTICAL && orientation != LinearLayoutManager.HORIZONTAL) {
throw new IllegalArgumentException("請輸入正確的參數！");
}
mOrientation = orientation;
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
}
/**
* 自定義分割線
*
* @param context
* @param orientation 列表方向
* @param drawableId 分割線圖片
*/
public RecycleViewDivider(Context context, int orientation, int drawableId) {
this(context, orientation);
mDivider = ContextCompat.getDrawable(context, drawableId);
mDividerHeight = mDivider.getIntrinsicHeight();
}
/**
* 自定義分割線
*
* @param context
* @param orientation 列表方向
* @param dividerHeight 分割線高度
* @param dividerColor 分割線顏色
*/
public RecycleViewDivider(Context context, int orientation, int dividerHeight, int dividerColor) {
this(context, orientation);
mDividerHeight = dividerHeight;
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setColor(dividerColor);
mPaint.setStyle(Paint.Style.FILL);
}
//獲取分割線尺寸
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
outRect.set(0, 0, 0, mDividerHeight);
}
//繪制分割線
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
super.onDraw(c, parent, state);
if (mOrientation == LinearLayoutManager.VERTICAL) {
drawVertical(c, parent);
} else {
drawHorizontal(c, parent);
}
}
//繪制橫向 item 分割線
private void drawHorizontal(Canvas canvas, RecyclerView parent) {
final int left = parent.getPaddingLeft();
final int right = parent.getMeasuredWidth() - parent.getPaddingRight();
final int childSize = parent.getChildCount();
for (int i = 0; i < childSize; i++) {
final View child = parent.getChildAt(i);
RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
final int top = child.getBottom() + layoutParams.bottomMargin;
final int bottom = top + mDividerHeight;
if (mDivider != null) {
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(canvas);
}
if (mPaint != null) {
canvas.drawRect(left, top, right, bottom, mPaint);
}
}
}
//繪制縱向 item 分割線
private void drawVertical(Canvas canvas, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getMeasuredHeight() - parent.getPaddingBottom();
final int childSize = parent.getChildCount();
for (int i = 0; i < childSize; i++) {
final View child = parent.getChildAt(i);
RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
final int left = child.getRight() + layoutParams.rightMargin;
final int right = left + mDividerHeight;
if (mDivider != null) {
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(canvas);
}
if (mPaint != null) {
canvas.drawRect(left, top, right, bottom, mPaint);
}
}
}
}

以上所述是小編給大家介紹的RecyclerView的萬能分割線，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對本站網站的支持！