为什么CameraX预览在真实设备上是模糊和模糊的，以及如何对焦？

val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA
val preview = Preview.Builder().build()

CameraX.bindToLifecycle(this, cameraSelector, preview)

preview.setOnPreviewOutputUpdateListener { previewOutput ->
    val textureView = findViewById<TextureView>(R.id.textureView)
    textureView.surfaceTexture = previewOutput.surfaceTexture
    textureView.post {
        // 设置合适的焦点区域
        val factory = textureView.meteringPointFactory
        val point = factory.createPoint(textureView.width / 2f, textureView.height / 2f)
        val action = FocusMeteringAction.Builder(point, FocusMeteringAction.FLAG_AF)
            .setAutoCancelDuration(5, TimeUnit.SECONDS)
            .build()

        CameraX.getCameraControl(cameraSelector).startFocusAndMetering(action)
    }
}