優(yōu)點
- 簡單易用：比Camera和Camera2 更簡潔
- 生命周期管理：CameraX 和 Lifecycle 結(jié)合在一起，方便管理。比camera2 少大量樣板代碼窃页。
- 兼容性：CameraX 基于Camera2 API 實現(xiàn)啤覆，兼容至 Android L (API 21)
- 擴展性：可以使用和原生攝像頭應(yīng)用同樣的功能（如：人像、夜間模式宅楞、HDR针姿、濾鏡袱吆、美顏）
- 自動化測試：對攝像頭功能進(jìn)行深度測試
使用
- 添加Gradle依賴
def camerax_version = "1.0.1"
// CameraX core library using camera2 implementation
implementation "androidx.camera:camera-camera2:$camerax_version"
// CameraX Lifecycle Library
implementation "androidx.camera:camera-lifecycle:$camerax_version"
// CameraX View class
implementation "androidx.camera:camera-view:1.0.0-alpha27"
- Java 8
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
- 布局
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/camera_capture_button"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginBottom="50dp"
android:scaleType="fitCenter"
android:text="Take Photo"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:elevation="2dp" />
<androidx.camera.view.PreviewView
android:id="@+id/viewFinder"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
- 權(quán)限
<uses-feature android:name="android.hardware.camera.any" />
<uses-permission android:name="android.permission.CAMERA" />
請求完權(quán)限之后
- startCamera
private fun startCamera() {
val cameraProviderFuture = ProcessCameraProvider.getInstance(this)
cameraProviderFuture.addListener(Runnable {
// Used to bind the lifecycle of cameras to the lifecycle owner
val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()
// Preview
preview = Preview.Builder()
.build()
// Select back camera
val cameraSelector = CameraSelector.Builder().requireLensFacing(CameraSelector.LENS_FACING_BACK).build()
try {
// Unbind use cases before rebinding
cameraProvider.unbindAll()
// Bind use cases to camera
camera = cameraProvider.bindToLifecycle(
this, cameraSelector, preview)
preview?.setSurfaceProvider(viewFinder.createSurfaceProvider(camera?.cameraInfo))
} catch(exc: Exception) {
Log.e(TAG, "Use case binding failed", exc)
}
}, ContextCompat.getMainExecutor(this))
}
1、創(chuàng)建的實例ProcessCameraProvider
2搓幌、偵聽器添加到中cameraProviderFuture
3杆故、添加ProcessCameraProvider，用于將相機的生命周期綁定到應(yīng)用程序進(jìn)程中的LifecycleOwner
4溉愁、初始化Preview
preview = Preview.Builder().build()
5处铛、CameraSelector 配置前后置鏡頭
val cameraSelector = CameraSelector.Builder().requireLensFacing(CameraSelector.LENS_FACING_BACK).build()
6、try拐揭、catch將cameraSelector和預(yù)覽對象綁定到cameraProvider撤蟆。將viewFinder的Surface提供程序附加到preview
- takePhoto 拍照
private fun takePhoto() {
// Get a stable reference of the modifiable image capture use case
val imageCapture = imageCapture ?: return
// Create timestamped output file to hold the image
val photoFile = File(
outputDirectory,
SimpleDateFormat(FILENAME_FORMAT, Locale.US
).format(System.currentTimeMillis()) + ".jpg")
// Create output options object which contains file + metadata
val outputOptions = ImageCapture.OutputFileOptions.Builder(photoFile).build()
// Setup image capture listener which is triggered after photo has
// been taken
imageCapture.takePicture(
outputOptions, ContextCompat.getMainExecutor(this), object : ImageCapture.OnImageSavedCallback {
override fun onError(exc: ImageCaptureException) {
Log.e(TAG, "Photo capture failed: ${exc.message}", exc)
}
override fun onImageSaved(output: ImageCapture.OutputFileResults) {
val savedUri = Uri.fromFile(photoFile)
val msg = "Photo capture succeeded: $savedUri"
Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
Log.d(TAG, msg)
}
})
}
1、獲得ImageCapture
2堂污、創(chuàng)建一個文件來保存圖像
3家肯、takePicture
