When we try to ZoomIn and ZoomOut on Xamarin Android, several color shades are occur Android version 7 and 8 only - xamarin.android

Question

In cameraPageRenderer, we handle zoomIn and zoomOut in our application. When we try to ZoomIn and ZoomOut, several colour shades occur. Please take a look at this image. As a result, we are resolving this issue by handling PrepareAndStartCamera (). Please see the code snippet below.
public override bool OnTouchEvent(MotionEvent e)
{
switch (e.Action & MotionEventActions.Mask)
{
case MotionEventActions.Down:
oldDist = getFingerSpacing(e);
break;
case MotionEventActions.Move:
float newDist = getFingerSpacing(e);
if (newDist > oldDist)
{
//mCamera is your Camera which used to take picture, it should already exit in your custom Camera
handleZoom(true, camera);
}
else if (newDist < oldDist)
{
handleZoom(false, camera);
}
oldDist = newDist;
break;
}
return true;
}
private static float getFingerSpacing(MotionEvent e)
{
if (e.PointerCount == 2)
{
float x = e.GetX(0) - e.GetX(1);
float y = e.GetY(0) - e.GetY(1);
return (float)Math.Sqrt(x * x + y * y);
}
return 0;
}
private void handleZoom(bool isZoomIn, global::Android.Hardware.Camera camera)
{
//camera.StopPreview();
// camera.Release();
// camera = global::Android.Hardware.Camera.Open((int)cameraType);
global::Android.Hardware.Camera.Parameters parameters = camera.GetParameters();
if (parameters.IsZoomSupported)
{
int maxZoom = parameters.MaxZoom;
int zoom = parameters.Zoom;
if (isZoomIn && zoom < maxZoom)
{
zoom++;
}
else if (zoom > 0)
{
zoom--;
}
parameters.Zoom = zoom;
camera.SetParameters(parameters);
camera.SetPreviewTexture(surfaceTexture);
// PrepareAndStartCamera();
}
else
{
Android.Util.Log.Error("lv", "zoom not supported");
}
}
After using PrepareAndStartCamera(), when ZoomingIn or ZoomingOut the camera and taking a picture, it returns to the normal size picture. if we are not using this PrepareAndStartCamera() method, then the Color shades are appear.
private void PrepareAndStartCamera()
{
try
{
camera.StopPreview();
var display = activity.WindowManager.DefaultDisplay;
if (display.Rotation == SurfaceOrientation.Rotation0)
{
camera.SetDisplayOrientation(90);
}
if (display.Rotation == SurfaceOrientation.Rotation270)
{
camera.SetDisplayOrientation(180);
}
camera.StartPreview();
}
}