好了，如果不需要改变你的分割线颜色，只需对分割线装饰应用alpha。

GridLayoutManager透明的示例:

DividerItemDecoration horizontalDividerItemDecoration = new DividerItemDecoration(WishListActivity.this,
                DividerItemDecoration.HORIZONTAL);
        horizontalDividerItemDecoration.getDrawable().setAlpha(50);
        DividerItemDecoration verticalDividerItemDecoration = new DividerItemDecoration(WishListActivity.this,
                DividerItemDecoration.VERTICAL);
        verticalDividerItemDecoration.getDrawable().setAlpha(50);
        my_recycler.addItemDecoration(horizontalDividerItemDecoration);
        my_recycler.addItemDecoration(verticalDividerItemDecoration);

你仍然可以通过设置颜色来改变分割线的颜色 过滤到它。

GridLayoutManager设置tint的例子:

DividerItemDecoration horizontalDividerItemDecoration = new DividerItemDecoration(WishListActivity.this,
                DividerItemDecoration.HORIZONTAL);
        horizontalDividerItemDecoration.getDrawable().setTint(getResources().getColor(R.color.colorAccent));
        DividerItemDecoration verticalDividerItemDecoration = new DividerItemDecoration(WishListActivity.this,
                DividerItemDecoration.VERTICAL);
        verticalDividerItemDecoration.getDrawable().setAlpha(50);
        my_recycler.addItemDecoration(horizontalDividerItemDecoration);
        my_recycler.addItemDecoration(verticalDividerItemDecoration);

此外，您还可以尝试设置颜色滤镜，

 horizontalDividerItemDecoration.getDrawable().setColorFilter(colorFilter);

所以这可能不是正确的方式，但我只是添加了一个视图到RecyclerView的单项视图(因为我不认为有一个内置的函数)，像这样:

<View
    android:layout_width="fill_parent"
    android:layout_height="@dimen/activity_divider_line_margin"
    android:layout_alignParentBottom="true"
    android:background="@color/tasklist_menu_dividerline_grey" />

这意味着每一项都有一行在底部填充。我把它做成1dp高，背景#111111。这也给了它一种“3D”效果。

recyclerview.addItemDecoration(new DividerItemDecoration(this, LinearLayoutManager.HORIZONTAL));

对于垂直线使用LinearLayoutManager。垂直

您可以创建一个简单的可重复使用的分隔器。

创建分频器:

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

    public DividerItemDecorator(Drawable divider) {
        mDivider = divider;
    }

    @Override
    public void onDraw(Canvas canvas, RecyclerView parent, RecyclerView.State state) {
        int dividerLeft = parent.getPaddingLeft();
        int dividerRight = 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 dividerTop = child.getBottom() + params.bottomMargin;
            int dividerBottom = dividerTop + mDivider.getIntrinsicHeight();

            mDivider.setBounds(dividerLeft, dividerTop, dividerRight, dividerBottom);
            mDivider.draw(canvas);
        }
    }
}

创建分隔线:separator .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="@color/grey_300" />
</shape>

为你的Recyclerview添加分隔符:

RecyclerView.ItemDecoration dividerItemDecoration = new DividerItemDecorator(ContextCompat.getDrawable(context, R.drawable.divider));
recyclerView.addItemDecoration(dividerItemDecoration);

删除最后一项的分隔符:

为了防止最后一项画分隔线，你必须改变这条线。

for (int i = 0; i < childCount; i++) 

To

for (int i = 0; i < childCount-1; i++)

你的最终实现应该是这样的:

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

    public DividerItemDecorator(Drawable divider) {
        mDivider = divider;
    }

    @Override
    public void onDraw(Canvas canvas, RecyclerView parent, RecyclerView.State state) {
        int dividerLeft = parent.getPaddingLeft();
        int dividerRight = parent.getWidth() - parent.getPaddingRight();

        int childCount = parent.getChildCount();
        for (int i = 0; i < childCount - 1; i++) {
            View child = parent.getChildAt(i);

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

            int dividerTop = child.getBottom() + params.bottomMargin;
            int dividerBottom = dividerTop + mDivider.getIntrinsicHeight();

            mDivider.setBounds(dividerLeft, dividerTop, dividerRight, dividerBottom);
            mDivider.draw(canvas);
        }
    }
}

希望能有所帮助。

Bhuvanesh BS解决方案有效。Kotlin版本:

import android.graphics.Canvas
import android.graphics.drawable.Drawable
import androidx.recyclerview.widget.RecyclerView

class DividerItemDecorator(private val mDivider: Drawable?) : RecyclerView.ItemDecoration() {

    override fun onDraw(
        canvas: Canvas,
        parent: RecyclerView,
        state: RecyclerView.State
    ) {

        val dividerLeft = parent.paddingLeft
        val dividerRight = parent.width - parent.paddingRight
        for (i in 0 until parent.childCount - 1) {
            val child = parent.getChildAt(i)
            val dividerTop =
                child.bottom + (child.layoutParams as RecyclerView.LayoutParams).bottomMargin
            val dividerBottom = dividerTop + mDivider!!.intrinsicHeight
            mDivider.setBounds(dividerLeft, dividerTop, dividerRight, dividerBottom)
            mDivider.draw(canvas)
        }
    }
}

yqritc的RecyclerView-FlexibleDivider使它成为一个内衬。首先把这个添加到你的build.gradle:

compile 'com.yqritc:recyclerview-flexibledivider:1.4.0' // requires jcenter()

现在你可以在你设置recyclerView的适配器的地方配置和添加一个分配器:

recyclerView.setAdapter(myAdapter);
recyclerView.addItemDecoration(new HorizontalDividerItemDecoration.Builder(this).color(Color.RED).sizeResId(R.dimen.divider).marginResId(R.dimen.leftmargin, R.dimen.rightmargin).build());