调用 RecyclerView.Adapter.notifyItemInserted() 时不应用 DividerItemDecoration

Question

I created a custom divider for a RecyclerView by extending DividerItemDecoration and then applying it by calling addItemDecoration on my RecyclerView.

The RecyclerView displays everything nicely untill my data set changes and I call notifyItemInserted . New item is indeed inserted in the RecyclerView, but it is displayed without my custom divider (dividers for the other items are in place).

When I scroll away from the newly inserted item and then return back to it - it appears with the divider in place.

EDIT Code snippets:

mRecyclerView.addItemDecoration(new GapDividerItemDecoration(mContext, LinearLayoutManager.VERTICAL, 16));

My custom decorator (just adds space between RecyclerView items provided in dp):

public class GapDividerItemDecoration extends DividerItemDecoration {

private int mSpaceInPixels;
private int mOrientation;

public GapDividerItemDecoration(Context context, int orientation, float dp) {
    super(context, orientation);
    mSpaceInPixels = dpToPixels(dp);
    mOrientation = orientation;
}

private int dpToPixels(float dp) {
    return (int) (dp * (((float) Resources.getSystem().getDisplayMetrics().densityDpi) / DisplayMetrics.DENSITY_DEFAULT));
}

@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
    // Do not draw the divider
}

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
    super.getItemOffsets(outRect, view, parent, state);
    if (parent.getChildAdapterPosition(view) != parent.getAdapter().getItemCount() - 1) {
        if (mOrientation == LinearLayout.VERTICAL) {
            outRect.bottom = mSpaceInPixels;
        } else {
            outRect.right = mSpaceInPixels;
        }
    }
}

I do not provide the rest of the code, because it is pretty straight forward (besides, I know that it is working, and the issue might be with the RecyclerView itself or just my custom decorator).

Answer 1

This is a too late answer, but I will answer because I have the same problem. Try call RecyclerView.invalidateItemDecorations() before insert data.