如何在RecyclerView中添加项目之间的分隔符和空格

这是之前在ListView类中使用divider和dividerHeight参数实现的一个例子:

<ListView
    android:id="@+id/activity_home_list_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:divider="@android:color/transparent"
    android:dividerHeight="8dp"/>

然而，在RecyclerView类中我没有看到这样的可能性。

<android.support.v7.widget.RecyclerView
    android:id="@+id/activity_home_recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scrollbars="vertical"/>

在这种情况下，是否可以定义边距和/或直接添加自定义分隔符视图到列表项的布局中，或者是否有更好的方法来实现我的目标?

当前回答

我认为使用一个简单的分隔器会对你有帮助

为每个项目添加分隔符:

1. 将其添加到可绘制目录line_divider.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<size
    android:width="1dp"
    android:height="1dp" />
<solid android:color="#999999" />
</shape>

2. 创建SimpleDividerItemDecoration类

我用这个例子来定义这个类:

https://gist.github.com/polbins/e37206fbc444207c0e92

package com.example.myapp;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import com.example.myapp.R;

public class SimpleDividerItemDecoration extends RecyclerView.ItemDecoration{
    private Drawable mDivider;

    public SimpleDividerItemDecoration(Resources resources) {
        mDivider = resources.getDrawable(R.drawable.line_divider);
    }

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

        int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = parent.getChildAt(i);

            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

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

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

3.在使用RecyclerView的活动或片段中，在onCreateView中添加以下内容:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
 RecyclerView myRecyclerView = (RecyclerView) layout.findViewById(R.id.my_recycler_view);
 myRecyclerView.addItemDecoration(new SimpleDividerItemDecoration(getResources()));
 ....
 }

4. 添加项目之间的间距

你只需要添加padding属性到你的项目视图

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:padding="4dp"
>
..... item structure
</RelativeLayout>

2015-04-04 13:12:53

其他回答

如果有人想为spaceBetween, paddingLeft, paddingTop, paddingRight和paddingBottom设置不同的值。

class ItemPaddingDecoration(
    private val spaceBetween: Int,
    private val paddingLeft: Int = spaceBetween,
    private val paddingTop: Int = spaceBetween,
    private val paddingRight: Int = spaceBetween,
    private val paddingBottom: Int = spaceBetween
) : RecyclerView.ItemDecoration() {

    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
        val position = parent.getChildAdapterPosition(view)
        val orientation = when (val layoutManager = parent.layoutManager) {
            is LinearLayoutManager -> {
                layoutManager.orientation
            }
            is GridLayoutManager -> {
                layoutManager.orientation
            }
            else -> {
                RecyclerView.HORIZONTAL
            }
        }
        if (orientation == RecyclerView.HORIZONTAL) {
            when {
                position == 0 -> {
                    outRect.set(paddingLeft, paddingTop, spaceBetween, paddingBottom)
                }
                position < parent.adapter!!.itemCount - 1 -> {
                    outRect.set(0, paddingTop, spaceBetween, paddingBottom)
                }
                else -> {
                    outRect.set(0, paddingTop, paddingRight, paddingBottom)
                }
            }
        } else {
            when {
                position == 0 -> {
                    outRect.set(paddingLeft, paddingTop, paddingRight, paddingBottom)
                }
                position < parent.adapter!!.itemCount - 1 -> {
                    outRect.set(paddingLeft, 0, paddingRight, spaceBetween)
                }
                else -> {
                    outRect.set(paddingLeft, 0, paddingRight, paddingBottom)
                }
            }
        }
    }
}

2022-02-03 10:11:39

我觉得需要一个简单的、不使用XML的、基于代码的答案

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL);

ShapeDrawable shapeDrawableForDivider = new ShapeDrawable(new RectShape());

int dividerThickness = // (int) (SomeOtherView.getHeight() * desiredPercent);
shapeDrawableForDivider.setIntrinsicHeight(dividerThickness);
shapeDrawableForDivider.setAlpha(0);

dividerItemDecoration.setDrawable(shapeDrawableForDivider);

recyclerView.addItemDecoration(dividerItemDecoration);

我非常喜欢这个答案，我用Kotlin的单一表达式重新写了一遍:

    recyclerView.addItemDecoration(DividerItemDecoration(this,DividerItemDecoration.VERTICAL).also { deco ->
        with (ShapeDrawable(RectShape())){
            intrinsicHeight = (resources.displayMetrics.density * 24).toInt()
            alpha = 0
            deco.setDrawable(this)
        }
    })

这和@Nerdy最初的答案是一样的，只是它将分隔线的高度设置为24dp，而不是另一个视图高度的百分比。

2018-09-26 07:51:10

这实际上并不能解决问题，但是作为一种临时的解决方法，您可以在XML布局中的卡片上设置useCompatPadding属性，使其与在前lollipop版本中测量的相同。

card_view:cardUseCompatPadding="true"

2014-12-13 20:13:56

如果你想为物品添加相同的空间，最简单的方法是为RecycleView添加顶部+左侧填充，为卡片物品添加右侧+底部空白。

文件dimens.xml

<resources>
    <dimen name="divider">1dp</dimen>
</resources>

文件list_item.xml

<CardView
    android:layout_marginBottom="@dimen/divider"
    android:layout_marginRight="@dimen/divider">

    ...
</CardView>

文件list.xml

<RecyclerView
    ...
    android:paddingLeft="@dimen/divider"
    android:paddingTop="@dimen/divider" />

2015-05-28 18:14:03