为什么 CameraXBasic 项目不将两个布局文件合并为一个？

Question

以下代码来自CameraXBasic project Github

CameraFragment.kt先加载fragment_camera.xml，再加载camera_ui_container.xml.

我觉得很奇怪 CameraXBasic 项目没有合并两个布局文件 fragment_camera.xml 和 camera_ui_container.xml合二为一，CameraFragment.kt只加载合并后的布局文件。

CameraFragment.kt

class CameraFragment : Fragment() {
    override fun onCreateView(
            inflater: LayoutInflater,
            container: ViewGroup?,
            savedInstanceState: Bundle?): View? =
            inflater.inflate(R.layout.fragment_camera, container, false)

    private fun updateCameraUi() {

        // Remove previous UI if any
        container.findViewById<ConstraintLayout>(R.id.camera_ui_container)?.let {
            container.removeView(it)
        }

        // Inflate a new view containing all UI for controlling the camera
        val controls = View.inflate(requireContext(), R.layout.camera_ui_container, container)
        ..
   }
}

fragment_camera.xml

 <androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/camera_container"
        android:background="@android:color/black"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextureView
            android:id="@+id/view_finder"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>

camera_ui_container.xml

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/camera_ui_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- Camera control and gallery buttons -->
    <ImageButton
        android:id="@+id/camera_switch_button"
        android:layout_width="@dimen/round_button_medium"
        android:layout_height="@dimen/round_button_medium"
        android:layout_marginBottom="@dimen/margin_xlarge"
        android:layout_marginLeft="@dimen/margin_small"
        android:padding="@dimen/spacing_small"
        android:scaleType="fitCenter"
        android:background="@android:color/transparent"
        app:srcCompat="@drawable/ic_switch"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:contentDescription="@string/switch_camera_button_alt" />

    <ImageButton
        android:id="@+id/camera_capture_button"
        android:layout_width="@dimen/round_button_large"
        android:layout_height="@dimen/round_button_large"
        android:layout_marginBottom="@dimen/shutter_button_margin"
        android:scaleType="fitCenter"
        android:background="@drawable/ic_shutter"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:contentDescription="@string/capture_button_alt" />

    <ImageButton
        android:id="@+id/photo_view_button"
        android:layout_width="@dimen/round_button_medium"
        android:layout_height="@dimen/round_button_medium"
        android:layout_marginBottom="@dimen/margin_xlarge"
        android:layout_marginRight="@dimen/margin_small"
        android:padding="@dimen/spacing_large"
        android:scaleType="fitCenter"
        android:background="@drawable/ic_outer_circle"
        app:srcCompat="@drawable/ic_photo"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:contentDescription="@string/gallery_button_alt" />

</androidx.constraintlayout.widget.ConstraintLayout>

添加内容

我测试了合并后的布局（Normal 和 landsacpe），效果很好，我觉得原版和我的速度差不多。

CameraFragment.kt（新）

private fun updateCameraUi() {

        // Remove previous UI if any
       // container.findViewById<ConstraintLayout>(R.id.camera_ui_container)?.let {
        //    container.removeView(it)
        //}

        // Inflate a new view containing all UI for controlling the camera
        //val controls = View.inflate(requireContext(), R.layout.camera_ui_container, container)

        // Listener for button used to capture photo
         ...
}

fragment_camera.xml （新）

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/camera_container"
    android:background="@android:color/black"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextureView
        android:id="@+id/view_finder"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <!-- Camera control and gallery buttons -->
    <ImageButton
        android:id="@+id/camera_switch_button"
        android:layout_width="@dimen/round_button_medium"
        android:layout_height="@dimen/round_button_medium"
        android:layout_marginBottom="@dimen/margin_xlarge"
        android:layout_marginLeft="@dimen/margin_small"
        android:padding="@dimen/spacing_small"
        android:scaleType="fitCenter"
        android:background="@android:color/transparent"
        app:srcCompat="@drawable/ic_switch"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:contentDescription="@string/switch_camera_button_alt" />

    <ImageButton
        android:id="@+id/camera_capture_button"
        android:layout_width="@dimen/round_button_large"
        android:layout_height="@dimen/round_button_large"
        android:layout_marginBottom="@dimen/shutter_button_margin"
        android:scaleType="fitCenter"
        android:background="@drawable/ic_shutter"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:contentDescription="@string/capture_button_alt" />

    <ImageButton
        android:id="@+id/photo_view_button"
        android:layout_width="@dimen/round_button_medium"
        android:layout_height="@dimen/round_button_medium"
        android:layout_marginBottom="@dimen/margin_xlarge"
        android:layout_marginRight="@dimen/margin_small"
        android:padding="@dimen/spacing_large"
        android:scaleType="fitCenter"
        android:background="@drawable/ic_outer_circle"
        app:srcCompat="@drawable/ic_photo"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:contentDescription="@string/gallery_button_alt" />

</androidx.constraintlayout.widget.ConstraintLayout>

fragment_camera.xml （新地）

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/camera_container"
    android:background="@android:color/black"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextureView
        android:id="@+id/view_finder"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <!-- Camera control and gallery buttons -->
    <ImageButton
        android:id="@id/camera_switch_button"
        android:layout_width="@dimen/round_button_medium"
        android:layout_height="@dimen/round_button_medium"
        android:layout_marginRight="@dimen/margin_xlarge"
        android:layout_marginBottom="@dimen/margin_small"
        android:padding="@dimen/spacing_small"
        android:scaleType="fitXY"
        android:background="@android:color/transparent"
        app:srcCompat="@drawable/ic_switch"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:contentDescription="@string/gallery_button_alt" />

    <ImageButton
        android:id="@id/camera_capture_button"
        android:layout_width="@dimen/round_button_large"
        android:layout_height="@dimen/round_button_large"
        android:layout_marginRight="@dimen/shutter_button_margin"
        android:background="@drawable/ic_shutter"
        android:contentDescription="@string/capture_button_alt"
        android:scaleType="fitXY"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageButton
        android:id="@id/photo_view_button"
        android:layout_width="@dimen/round_button_medium"
        android:layout_height="@dimen/round_button_medium"
        android:layout_marginRight="@dimen/margin_xlarge"
        android:layout_marginTop="@dimen/margin_small"
        android:padding="@dimen/spacing_large"
        android:scaleType="fitXY"
        android:background="@drawable/ic_outer_circle"
        app:srcCompat="@drawable/ic_photo"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:contentDescription="@string/switch_camera_button_alt" />
</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

他们的想法是每次配置更改时重新创建 UI，而 TextureView 仍然存在。

Answer 2

您是否注意到有两个 XML camera_ui_container.xml 文件，一个用于纵向，一个用于横向，以实现不同的 UI 旋转。和行

// Remove previous UI if any

container.findViewById(R.id.camera_ui_container)?.let { container.removeView(it) }

实际上是在做相机的娱乐部分UI @Alex Cohn 是对的，在同一点上。

如果您只处理单一方向，则可以使用单一布局。

为什么 CameraXBasic 项目不将两个布局文件合并为一个？

Why doesn't CameraXBasic project merge two layout files into one?

android

android-camerax