Unity 3D自动对焦

using UnityEngine;
using System.Collections;
using Vuforia;

public class CameraMode : MonoBehaviour
{

    // Use this for initialization
    void Start ()
    {

        VuforiaARController.Instance.RegisterVuforiaStartedCallback (OnVuforiaStarted);
        VuforiaARController.Instance.RegisterOnPauseCallback (OnPaused);
    }

    void Update ()
    {

    }

    private void OnVuforiaStarted ()
    {
        CameraDevice.Instance.SetFocusMode (
            CameraDevice.FocusMode.FOCUS_MODE_CONTINUOUSAUTO);
    }

    private void OnPaused (bool paused)
    {
        if (!paused) { // resumed
            // Set again autofocus mode when app is resumed
            CameraDevice.Instance.SetFocusMode (
                CameraDevice.FocusMode.FOCUS_MODE_CONTINUOUSAUTO);
        }
    }
}