Jetpack之CameraX的使用
幸大叔 人气:0引入依赖
下面,就使用该库来打造一个简单的相机应用吧~
首先引入依赖
def camerax_version = "1.1.0-beta03"
implementation "androidx.camera:camera-core:${camerax_version}"
implementation "androidx.camera:camera-camera2:${camerax_version}"
implementation "androidx.camera:camera-lifecycle:${camerax_version}"
implementation "androidx.camera:camera-video:${camerax_version}"
implementation "androidx.camera:camera-view:${camerax_version}"
implementation "androidx.camera:camera-extensions:${camerax_version}"
预览
将 PreviewView 添加到布局中
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout 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" tools:context=".MainActivity"> <androidx.camera.view.PreviewView android:id="@+id/previewView" android:layout_width="match_parent" android:layout_height="match_parent" /> <Button android:id="@+id/take" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:text="拍照" /> </RelativeLayout>
获取 cameraProvider
val cameraProviderFuture = ProcessCameraProvider.getInstance(this) cameraProviderFuture.addListener({ val cameraProvider = cameraProviderFuture.get() bindViewAndLifecycle(cameraProvider) }, ContextCompat.getMainExecutor(this))
配置 ImageCapture
private val imageCapture: ImageCapture by lazy { ImageCapture.Builder().build() }
bindViewAndLifecycle:绑定视图和Lifecycle
private fun bindViewAndLifecycle(cameraProvider: ProcessCameraProvider) { val previewView = findViewById<PreviewView>(R.id.previewView) val cameraSelector = CameraSelector.Builder() //如果是前置,可使用CameraSelector.LENS_FACING_FRONT .requireLensFacing(CameraSelector.LENS_FACING_BACK) .build() val preview = Preview.Builder().build() preview.setSurfaceProvider(previewView.surfaceProvider) cameraProvider.bindToLifecycle( this as LifecycleOwner, cameraSelector, imageCapture, preview ) }
这样,就完成了相机的预览功能了。
拍摄
实现拍照功能也很简单,只需要创建文件,然后调用imageCapture的takePicture方法。
private fun takePicture() { val path = getExternalFilesDir(null)?.absolutePath + File.separator + System.currentTimeMillis() + ".jpg" val photoFile = File(path) if (!photoFile.exists()) { photoFile.createNewFile() } val fileOptions = ImageCapture.OutputFileOptions.Builder(photoFile).build() imageCapture.takePicture( fileOptions, ContextCompat.getMainExecutor(this), object : ImageCapture.OnImageSavedCallback { override fun onImageSaved(outputFileResults: ImageCapture.OutputFileResults) { Toast.makeText(this@MainActivity, "保存成功", Toast.LENGTH_SHORT).show() } override fun onError(exception: ImageCaptureException) { Log.e(tag, "onError message:${exception.message}") } }) }
点击按钮时调用此方法即可
findViewById<Button>(R.id.take).setOnClickListener { takePicture() }
注意:作为相机应用,可别忘了申请CAMERA权限哦。
这样,一个简单的相机应用就完成啦~
加载全部内容