在导航视图之间添加分隔线

Question

我需要在应用程序中的两个导航视图之间添加一个分隔线。（navigation_drawer_top和navigation_drawer_bottom）。

我已经尝试过。但这增加了视图的顶部。不在第一个NavigationView（navigation_drawer_top）的末尾。

<View android:layout_width="match_parent"
          android:layout_height="1dp"
          android:background="?android:attr/listDivider"/>

这是我的代码

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">
    <include
        layout="@layout/app_bar_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <android.support.design.widget.NavigationView
        android:id="@+id/navigation_drawer_container"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start">
        <android.support.design.widget.NavigationView
            android:id="@+id/navigation_drawer_top"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="top"
            android:background="@color/menuColor"
            android:paddingLeft="50dp"
            app:headerLayout="@layout/nav_header_main"
            app:itemTextAppearance="@style/NavigationDrawerStyle"
            app:itemTextColor="@color/menuTextColour"
            app:menu="@menu/menu_navigation_drawer_top"
            />
        <android.support.design.widget.NavigationView
            android:id="@+id/navigation_drawer_bottom"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@color/menuColor"
            android:layout_gravity="bottom"
            android:paddingLeft="50dp"
            app:itemTextAppearance="@style/NavigationDrawerStyle"
            app:itemTextColor="@color/menuTextColour"
            app:menu="@menu/menu_navigation_drawer_bottom" />
    </android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>

Answer 1

尝试此

<View
android:layout_below="@+id/id_of_item_below_which_you_want_it"
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="?android:attr/listDivider"/>

Answer 2

这很简单。您需要做的就是组成一个组，并将独特的ID放在组上。唯一的ID是在将分隔线添加到菜单中的真正技巧。

这是您的快速示例，

<group android:id="@+id/group1" android:checkableBehavior="single" >
    <item
        android:id="@+id/item_1"
        android:checked="true"
        android:icon="@drawable/ic_1"
        android:title="@string/title_1" />
</group>
<group android:id="@+id/group2" android:checkableBehavior="single" >
    <item
        android:id="@+id/item_2"
        android:icon="@drawable/ic_2"
        android:title="@string/title_2" />
</group>

这肯定会添加分隔符在您的菜单中。

编辑当您以编程方式添加菜单时，您应该尝试访问每个NavigationMenuview并向它们添加一个装饰器。

NavigationView navigationView = (NavigationView) findViewById(R.id.navigation);
NavigationMenuView navMenuView = (NavigationMenuView) navigationView.getChildAt(0);
navMenuView.addItemDecoration(new DividerItemDecoration(appContext,DividerItemDecoration.VERTICAL_LIST))

这是您的DividerItemDecoration类，

public class DividerItemDecoration extends RecyclerView.ItemDecoration {
    private static final int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };
    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
    private Drawable mDivider;
    private int mOrientation;
    public DividerItemDecoration(Context context, int orientation) {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }
    public void setOrientation(int orientation) {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }
    @Override
    public void onDraw(Canvas c, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }
    }
    public void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();
        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
    public void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();
        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
    @Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST) {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}