title: Why does zoomRatio display the error Unresolved reference when I use camerax "1.0.0-alpha06"?
body: <p>I have read the artical. <a href="https://proandroiddev.com/android-camerax-tap-to-focus-pinch-to-zoom-zoom-slider-eb88f3aa6fc6" rel="noreferrer">https://proandroiddev.com/android-camerax-tap-to-focus-pinch-to-zoom-zoom-slider-eb88f3aa6fc6</a></p>
  
  <p>I add Code A to the office camerx sample.  <a href="https://github.com/android/camera-samples/tree/master/CameraXBasic" rel="noreferrer">https://github.com/android/camera-samples/tree/master/CameraXBasic</a></p>
  
  <p>The sample code use camerax "1.0.0-alpha06"</p>
  
  <p>I get the error Unresolved reference for zoomRatio, you can see Image 1, how can I fix it? </p>
  
  <p><strong>Code A</strong></p>
  
  <pre><code> private fun setUpPinchToZoom() {
          val cameraControl = CameraX.getCameraControl(lensFacing)
          val cameraInfo = CameraX.getCameraInfo(lensFacing)
  
          val listener = object : ScaleGestureDetector.SimpleOnScaleGestureListener() {
              override fun onScale(detector: ScaleGestureDetector): Boolean {
                  val currentZoomRatio: Float = cameraInfo.zoomRatio.value ?: 0F
                  val delta = detector.scaleFactor
                  cameraControl.setZoomRatio(currentZoomRatio * delta)
                  return true
              }
          }
  
          val scaleGestureDetector = ScaleGestureDetector(context, listener)
  
          viewFinder.setOnTouchListener { _, event -&gt;
              scaleGestureDetector.onTouchEvent(event)
              return@setOnTouchListener true
          }
      }
  </code></pre>
  
  <p><strong>Image 1</strong>
  <a href="https://i.stack.imgur.com/kl3Ru.png" rel="noreferrer"><img src="https://i.stack.imgur.com/kl3Ru.png" alt="enter image description here"></a></p>