android - Google Apps 中基于 Material Design 2 的自定义选择标签指示器

Question

我正在寻找一种方法来制作基于 Google 最新 Material Design 的圆丸/圆角选项卡指示器。我制作了一个具有所需结果的可绘制对象并将其实现为“app:tabIndicator”，但它无法正常工作。

This is what I want to achieve

rounded_tab_indicator.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:bottom="5dp"
        android:end="5dp"
        android:start="5dp">
        <shape
            android:shape="rectangle"
            app:tabIndicatorFullWidth="false"
            app:tabIndicatorHeight="5dp">
            <corners android:radius="8dp" />
            <solid android:color="@color/colorPrimary" />
        </shape>
    </item>
</layer-list>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="com.example.android.tourguideapp.MainActivity">

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/htab_appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <com.google.android.material.appbar.CollapsingToolbarLayout
            android:id="@+id/htab_collapse_toolbar"
            android:layout_width="match_parent"
            android:layout_height="256dp"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|exitUntilCollapsed|snap"
            app:titleEnabled="false">

            <ImageView
                android:id="@+id/tour_image_view"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@drawable/dscn0585"
                android:fitsSystemWindows="true"
                android:scaleType="centerCrop"
                app:layout_collapseMode="parallax"
                app:layout_collapseParallaxMultiplier="0.80" />

            <View
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:alpha="0.3"
                android:background="@android:color/black"
                android:fitsSystemWindows="true" />

            <androidx.appcompat.widget.Toolbar
                android:id="@+id/htab_toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:layout_gravity="top"
                android:layout_marginBottom="40dp"
                app:layout_collapseMode="pin"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

            <com.google.android.material.tabs.TabLayout
                android:id="@+id/tabs"
                style="@style/CategoryTab"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"
                app:tabIndicatorHeight="5dp"
                app:tabIndicator="@drawable/rounded_tab_indicator"
                app:layout_collapseMode="pin"
                app:tabMode="scrollable" />

        </com.google.android.material.appbar.CollapsingToolbarLayout>

    </com.google.android.material.appbar.AppBarLayout>

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>

Answer 1

标签指示器可绘制:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <size
        android:width="100dp"
        android:height="2dp" />
    <corners
        android:topLeftRadius="8dp"
        android:topRightRadius="8dp">
     </corners>
    <solid
        android:color="#1475e7">
    </solid>
</shape>

标签布局:

<com.google.android.material.tabs.TabLayout
    ...
    app:tabIndicatorFullWidth="false"
    app:tabIndicator="@drawable/tab_indicator"
    ... />