SimplePreviewActivity.kt

private var captureSession: CameraCaptureSession? = null

private fun createCameraPreviewSession() {
    if (cameraDevice == null) {
        return
    }
    val texture = textureView.surfaceTexture
    texture.setDefaultBufferSize(640, 480)
    val surface = Surface(texture)

    val previewRequestBuilder = cameraDevice!!.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW)
    previewRequestBuilder.addTarget(surface)

    cameraDevice?.createCaptureSession(listOf(surface), object : CameraCaptureSession.StateCallback() {
        override fun onConfigured(session: CameraCaptureSession) {
            captureSession = session
            captureSession?.setRepeatingRequest(previewRequestBuilder.build(), null, null)
        }

        override fun onConfigureFailed(session: CameraCaptureSession) {}
    }, null)
}