•PrimeAdapter

通过使用PrimeAdapter，在RecyclerViews中处理分隔符可以非常简单。它为创建和管理分隔器提供了多种功能和更大的灵活性。

您可以按以下方式创建适配器(请参阅GitHub中关于使用的完整文档):

val adapter = PrimeAdapter.with(recyclerView)
                    .setLayoutManager(LinearLayoutManager(activity))
                    .set()
                    .build(ActorAdapter::class.java)

创建适配器实例后，您可以简单地使用以下命令添加分隔符:

//----- Default divider:
adapter.setDivider()

//----- Divider with a custom drawable:
adapter.setDivider(ContextCompat.getDrawable(context, R.drawable.divider))

//----- Divider with a custom color:
adapter.setDivider(Color.RED)

//----- Divider with a custom color and a custom inset:
adapter.setDivider(Color.RED, insetLeft = 16, insetRight = 16)

//----- Deactivate dividers:
adapter.setDivider(null)

为视图添加边距。这对我很管用。

android:layout_marginTop="10dp"

如果你只是想在XML中添加相等的间距，只需在RecyclerView中设置padding，并在你膨胀到RecyclerView中的项目中设置等量的layoutMargin，并让背景颜色决定间距颜色。

以下是我的偷懒方法，但它很有效: 将CardView包装在一个布局中，并在父布局上设置一个填充/边距来模拟分隔符，并强制将普通分隔符设置为null。

文件list_item.xml

<LinearLayout
    android:id="@+id/entry_item_layout_container"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:paddingBottom="<divider_size>" > // This is the divider
    <CardView
        android:layout_width="<width_size>"
        android:layout_height="<height_size>">
        ...
    </CardView>
</LinearLayout

文件list.xml

<RecyclerView
    android:divider="@null"
    android:layout_width="<width_size>"
    android:layout_height="<height_size>"
    ...
/>

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>

这很简单，你不需要这么复杂的代码:

DividerItemDecoration divider = new DividerItemDecoration(
    mRVMovieReview.getContext(), DividerItemDecoration.VERTICAL
);
divider.setDrawable(
    ContextCompat.getDrawable(getBaseContext(), R.drawable.line_divider)
);

mRVMovieReview.addItemDecoration(divider);

将它添加到你的drawable: line_divide .xml中

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <size android:height="1dp" />
    <solid android:color="@android:color/black" />
</shape>

public class CommonItemSpaceDecoration extends RecyclerView.ItemDecoration {

    private int mSpace = 0;
    private boolean mVerticalOrientation = true;

    public CommonItemSpaceDecoration(int space) {
        this.mSpace = space;
    }

    public CommonItemSpaceDecoration(int space, boolean verticalOrientation) {
        this.mSpace = space;
        this.mVerticalOrientation = verticalOrientation;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        outRect.top = SizeUtils.dp2px(view.getContext(), mSpace);
        if (mVerticalOrientation) {
            if (parent.getChildAdapterPosition(view) == 0) {
                outRect.set(0, SizeUtils.dp2px(view.getContext(), mSpace), 0, SizeUtils.dp2px(view.getContext(), mSpace));
            } else {
                outRect.set(0, 0, 0, SizeUtils.dp2px(view.getContext(), mSpace));
            }
        } else {
            if (parent.getChildAdapterPosition(view) == 0) {
                outRect.set(SizeUtils.dp2px(view.getContext(), mSpace), 0, 0, 0);
            } else {
                outRect.set(SizeUtils.dp2px(view.getContext(), mSpace), 0, SizeUtils.dp2px(view.getContext(), mSpace), 0);
            }
        }
    }
}

这将增加每个项目的顶部和底部(或左右)的空间。然后你可以将它设置为你的recyclerView。

recyclerView.addItemDecoration(new CommonItemSpaceDecoration(16));

文件SizeUtils.java

public class SizeUtils {
    public static int dp2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }
}