Implementing CameraX API for Camera Functionality in Android
With the release of the CameraX API, developers now have a powerful and easy-to-use solution for implementing camera functionality in their Android applications. CameraX simplifies the process of capturing photos and videos, enabling developers to focus more on their app’s unique features. In this blog post, we will explore how to integrate CameraX API into your Android app using Kotlin.
Prerequisites
Before we start implementing the CameraX API, make sure you have the following:
- Android Studio (latest version recommended)
- Android device (physical or emulator) with API level 21 or higher
Setting up CameraX API
To set up CameraX API in your Android application, follow these steps:
Step 1: Add CameraX dependencies to your project
Open your app-level build.gradle file and add the following dependencies:
android {
...
defaultConfig {
...
vectorDrawables.useSupportLibrary = true
}
}
dependencies {
...
def camerax_version = "1.1.0-alpha04"
// CameraX core library
implementation "androidx.camera:camera-core:$camerax_version"
// CameraX utilities
implementation "androidx.camera:camera-camera2:$camerax_version"
// CameraX lifecycle library
implementation "androidx.camera:camera-lifecycle:$camerax_version"
// CameraX view viewfinder
implementation "androidx.camera:camera-view:$camerax_version"
}
Make sure to sync your project files after adding these dependencies.
Step 2: Add CameraXView to your layout
Open your activity’s XML layout file and add the CameraXView element:
<androidx.camera.view.CameraView
android:id="@+id/cameraView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
Step 3: Set up CameraX in your activity or fragment
In your activity or fragment’s code, initialize the CameraX API by adding the following code:
class MainActivity : AppCompatActivity() {
private var camera: Camera? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
if (allPermissionsGranted()) {
startCamera()
} else {
ActivityCompat.requestPermissions(
this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS
)
}
}
private fun allPermissionsGranted() = REQUIRED_PERMISSIONS.all {
ContextCompat.checkSelfPermission(
baseContext, it
) == PackageManager.PERMISSION_GRANTED
}
private fun startCamera() {
val previewConfig = PreviewConfig.Builder().build()
val preview = Preview(previewConfig)
val imageCaptureConfig = ImageCaptureConfig.Builder().build()
val imageCapture = ImageCapture(imageCaptureConfig)
val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA
CameraX.bindToLifecycle(this, cameraSelector, preview, imageCapture)
cameraView.post {
cameraView?.let {
preview.setSurfaceProvider(it.createSurfaceProvider())
}
}
}
// Handle permission request result
override fun onRequestPermissionsResult(
requestCode: Int,
permissions: Array<String>,
grantResults: IntArray
) {
if (requestCode == REQUEST_CODE_PERMISSIONS) {
if (allPermissionsGranted()) {
startCamera()
} else {
Toast.makeText(
this,
"Permissions not granted by the user.",
Toast.LENGTH_SHORT
).show()
finish()
}
}
}
companion object {
private const val REQUEST_CODE_PERMISSIONS = 10
private val REQUIRED_PERMISSIONS = arrayOf(Manifest.permission.CAMERA)
}
}
Conclusion
Implementing camera functionality in Android has become simpler and more convenient with the introduction of the CameraX API. In this blog post, we discussed the steps involved in setting up CameraX and integrating it into your Android app using Kotlin. By following these steps, you should now have a working CameraX implementation in your app.
CameraX API offers several powerful features and customization options to enhance the camera functionality of your app. You can explore more in the official CameraX documentation and experiment with different configurations to meet your app’s requirements.
参考文献：