Question

我有一个带有gridlayout的recyclerview。我想要的是当用户滚动到列表末尾（see my bad mockup）时，应该有一个空格，高度为50dp，与我的网格尺寸不同。

请注意，此空间仅在最末端可见，因为我不想更改布局。我可以这样做，以便recycerview的边距为50dp，但我不想这样做。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:fab="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity"
        android:scrollbars="vertical"
        />

</RelativeLayout>

Answer 1

<RecyclerView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="50dp"
    android:clipToPadding="false"
    />

Answer 2

最好使用item decoration。

这是一个与LinearLayoutManager一起使用的示例 - 您必须进行调整以适应您的网格布局。它做的是检查每个项目以查看它是否是最后一个项目，如果是，则将偏移量添加到它的底部。对于网格布局，困难的部分是确定您的项目位置是否在最后一行。

// After setting layout manager, adapter, etc...
float offsetPx = getResources().getDimension(R.dimen.bottom_offset_dp);
BottomOffsetDecoration bottomOffsetDecoration = new BottomOffsetDecoration((int) offsetPx);
mRecyclerView.addItemDecoration(bottomOffsetDecoration);

...

static class BottomOffsetDecoration extends RecyclerView.ItemDecoration {
    private int mBottomOffset;

    public BottomOffsetDecoration(int bottomOffset) {
        mBottomOffset = bottomOffset;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        int dataSize = state.getItemCount();
        int position = parent.getChildAdapterPosition(view);
        if (dataSize > 0 && position == dataSize - 1) {
            outRect.set(0, 0, 0, mBottomOffset);
        } else {
            outRect.set(0, 0, 0, 0);
        }

    }
}

对于GridLayoutManager，在getItemOffsets方法中，您可以执行与此类似的操作，以确定它是否为最后一行：

GridLayoutManager grid = (GridLayoutManager)parent.getLayoutManager();
if ((dataSize - position) <= grid.getSpanCount()) {
    outRect.set(0, 0, 0, mBottomOffset);
} else {
    outRect.set(0, 0, 0, 0);
}

Answer 3

我有类似的问题。阅读所有其他答复后，我发现recyclerview布局xml中的更改按预期可用于我的recycler视图：

        android:paddingBottom="127px"
        android:clipToPadding="false"
        android:scrollbarStyle="outsideOverlay"

完整的布局如下：

<android.support.v7.widget.RecyclerView
        android:id="@+id/library_list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="160px"
        android:layout_marginEnd="160px"
        tools:listitem="@layout/library_list_item" />

有关之前和之后的效果，请参见androidblog.us上的链接： Adding Space to End of Android Recylerview
让我知道它如何为您工作。

大卫

Answer 4

您可以尝试以下代码，记住＆＃34;我不测试此代码＆＃34;

public class MyRecyclerView extends RecyclerView {
    private Context context;
    public MyRecyclerView(Context context) {
        super(context);
        this.context = context;

    }

    public MyRecyclerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.context = context;
    }

    public MyRecyclerView(Context context, AttributeSet attrs, int defStyle)     {
        super(context, attrs, defStyle);
        this.context = context;
    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        View view = (View) getChildAt(getChildCount()-1);
        int diff = (view.getBottom()-(getHeight()+getScrollY()+view.getTop()));
        if( diff == 0 ){  // if diff is zero, then the bottom has been reached
            TextView tv = new TextView(context);
            tv.setHeight(dpToPx(50));
            addView(tv,getChildCount());//update --> add to last
            requestLayout();
        }
        super.onScrollChanged(l, t, oldl, oldt);
    }
    public int dpToPx(int dp) {
        DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
        int px = Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
        return px;
    }
}

并在布局中：

<your_packagae.MyRecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scrollbars="vertical"
    />

Answer 5

使用BottomOffsetDecoration创建一个类名

public class BottomOffsetDecoration extends RecyclerView.ItemDecoration {
        private int mBottomOffset;
    
        public BottomOffsetDecoration(int bottomOffset) {
            mBottomOffset = bottomOffset;
        }
    
        @Override
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
            super.getItemOffsets(outRect, view, parent, state);
            int dataSize = state.getItemCount();
            int position = parent.getChildAdapterPosition(view);
            if (dataSize > 0 && position == dataSize - 1) {
                outRect.set(0, 0, 0, mBottomOffset);
            } else {
                outRect.set(0, 0, 0, 0);
            }
    
        }
    }

然后在将adapter和layoutmanager添加到recyclerview后添加这些行

float offsetPx = getResources().getDimension(R.dimen.bottom_offset_dp);
        BottomOffsetDecoration bottomOffsetDecoration = new BottomOffsetDecoration((int) offsetPx);
        rv.addItemDecoration(bottomOffsetDecoration);

并为 GridLayout 在分配 recyclerview 布局管理器后添加这些行

GridLayoutManager grid = (GridLayoutManager)parent.getLayoutManager();
if ((dataSize - position) <= grid.getSpanCount()) {
    outRect.set(0, 0, 0, mBottomOffset);
} else {
    outRect.set(0, 0, 0, 0);
}

在RecyclerView的末尾添加空间

5 个答案: