试试这个简单的单行代码

recyclerView.addItemDecoration(new DividerItemDecoration(getContext(),LinearLayoutManager.VERTICAL)); 

正确的方法是为RecyclerView定义ItemDecoration如下所示

SimpleDividerItemDecoration.java

public class SimpleDividerItemDecoration extends RecyclerView.ItemDecoration {
    private Drawable mDivider;
 
    public SimpleDividerItemDecoration(Context context) {
        mDivider = ContextCompat.getDrawable(context, R.drawable.line_divider);
    }
 
    @Override
    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);
        }
    }
}

或者如果您正在使用kotlin: SimpleDividerItemDecoration.kt

class SimpleDividerItemDecoration(context: Context, @DrawableRes dividerRes: Int) : ItemDecoration() {

    private val mDivider: Drawable = ContextCompat.getDrawable(context, dividerRes)!!

    override fun onDrawOver(c: Canvas, parent: RecyclerView) {
        val left = parent.paddingLeft
        val right = parent.width - parent.paddingRight
        val childCount = parent.childCount
        for (i in 0 until childCount) {
            val child: View = parent.getChildAt(i)
            val params = child.layoutParams as RecyclerView.LayoutParams
            val top: Int = child.bottom + params.bottomMargin
            val bottom = top + mDivider.intrinsicHeight
            mDivider.setBounds(left, top, right, bottom)
            mDivider.draw(c)
        }
    }
}
    

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="@color/dark_gray" />
 
</shape>

最后像这样设置

recyclerView.addItemDecoration(new SimpleDividerItemDecoration(this));

Edit

正如@Alan Solitar指出的那样

context.getResources().getDrawable(R.drawable.line_divider); 

是折旧而不是你可以使用的

ContextCompat.getDrawable(context,R.drawable.line_divider);

不幸的是，Android只是把小事情变得太复杂了。实现你想要的最简单的方法，没有实现这里的DividerItemDecoration:

为RecyclerView添加你想要的分割线颜色的背景色:

<RecyclerView
    android:id="@+id/rvList"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:divider="@color/colorLightGray"
    android:scrollbars="vertical"
    tools:listitem="@layout/list_item"
    android:background="@android:color/darker_gray"/>

添加底部边距(android:layout_marginBottom)到项目的布局根(list_item.xml):

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginBottom="1dp">

    <TextView
        android:id="@+id/tvName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="John Doe" />

    <TextView
        android:id="@+id/tvDescription"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/tvName"
        android:text="Some description blah blah" />

</RelativeLayout>

这将在项目和RecyclerView的背景色之间提供1dp的空间(它是深灰色，将作为分隔符出现)。

如果你想同时使用水平和垂直分隔符:

Define horizontal & vertical divider drawables: horizontal_divider.xml <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" > <size android:height="1dip" /> <solid android:color="#22000000" /> </shape> vertical_divider.xml <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" > <size android:width="1dip" /> <solid android:color="#22000000" /> </shape> Add this code segment below: DividerItemDecoration verticalDecoration = new DividerItemDecoration(recyclerview.getContext(), DividerItemDecoration.HORIZONTAL); Drawable verticalDivider = ContextCompat.getDrawable(getActivity(), R.drawable.vertical_divider); verticalDecoration.setDrawable(verticalDivider); recyclerview.addItemDecoration(verticalDecoration); DividerItemDecoration horizontalDecoration = new DividerItemDecoration(recyclerview.getContext(), DividerItemDecoration.VERTICAL); Drawable horizontalDivider = ContextCompat.getDrawable(getActivity(), R.drawable.horizontal_divider); horizontalDecoration.setDrawable(horizontalDivider); recyclerview.addItemDecoration(horizontalDecoration);

我认为这是最简单的方法

mDividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(),
                DividerItemDecoration.VERTICAL);
// or DividerItemDecoration.HORIZONTALL
        mDividerItemDecoration.setDrawable(getDrawable(R.drawable.myshape));
        recyclerView.addItemDecoration(mDividerItemDecoration);

注意:myshape可以是你想要做分隔的高度的矩形

下面是一个简单的自定义分割线(垂直分割线/ 1dp高度/黑色)的代码:

假设你有支持库:

compile "com.android.support:recyclerview-v7:25.1.1"

java代码

    DividerItemDecoration divider = new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL);
    divider.setDrawable(ContextCompat.getDrawable(getBaseContext(), R.drawable.my_custom_divider));
    recyclerView.addItemDecoration(divider);

然后custom_divide .xml文件示例:

<?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>