Unity 使用Vuforia实现识别图后触发其他事件的方法

在ImageTarget组件物体上找到DefaultTrackableEventHandler脚本，使用VS打开，通过里面的两个方法实现

OnTrackingFound()—>识别图片成功后触发
OnTrackingLost()—>识别图丢失后触发

通过上面两个方法可以实现 控制音频、视频和动画等的播放与停止。

代码：

/*==============================================================================
Copyright (c) 2017 PTC Inc. All Rights Reserved.

Copyright (c) 2010-2014 Qualcomm Connected Experiences, Inc.
All Rights Reserved.
Confidential and Proprietary - Protected under copyright and other laws.
==============================================================================*/

using UnityEngine;
using Vuforia;
using UnityEngine.UI;
/// 

///     A custom handler that implements the ITrackableEventHandler interface.
/// 
public class DefaultTrackableEventHandler : MonoBehaviour, ITrackableEventHandler
{
    

    #region PRIVATE_MEMBER_VARIABLES

    protected TrackableBehaviour mTrackableBehaviour;

    #endregion // PRIVATE_MEMBER_VARIABLES

    #region UNTIY_MONOBEHAVIOUR_METHODS

    protected virtual void Start()
    {
        mTrackableBehaviour = GetComponent();
        if (mTrackableBehaviour)
            mTrackableBehaviour.RegisterTrackableEventHandler(this);
    }

    #endregion // UNTIY_MONOBEHAVIOUR_METHODS

    #region PUBLIC_METHODS

    /// 

    ///     Implementation of the ITrackableEventHandler function called when the
    ///     tracking state changes.
    /// 
    //识别状态转变时触发
    public void OnTrackableStateChanged(
        TrackableBehaviour.Status previousStatus,
        TrackableBehaviour.Status newStatus)
    {
        if (newStatus == TrackableBehaviour.Status.DETECTED ||
            newStatus == TrackableBehaviour.Status.TRACKED ||
            newStatus == TrackableBehaviour.Status.EXTENDED_TRACKED)
        {
            Debug.Log("Trackable " + mTrackableBehaviour.TrackableName + " found");
            OnTrackingFound();
        }
        else if (previousStatus == TrackableBehaviour.Status.TRACKED &&
                 newStatus == TrackableBehaviour.Status.NOT_FOUND)
        {
            Debug.Log("Trackable " + mTrackableBehaviour.TrackableName + " lost");
            OnTrackingLost();
        }
        else
        {
            // For combo of previousStatus=UNKNOWN + newStatus=UNKNOWN|NOT_FOUND
            // Vuforia is starting, but tracking has not been lost or found yet
            // Call OnTrackingLost() to hide the augmentations
            OnTrackingLost();
        }
    }

    #endregion // PUBLIC_METHODS

    #region PRIVATE_METHODS
//成功识别图后触发 
    protected virtual void OnTrackingFound()
    {
        var rendererComponents = GetComponentsInChildren(true);
        var colliderComponents = GetComponentsInChildren(true);
        var canvasComponents = GetComponentsInChildren(true);

        // Enable rendering:
        foreach (var component in rendererComponents)
            component.enabled = true;

        // Enable colliders:
        foreach (var component in colliderComponents)
            component.enabled = true;

        // Enable canvas':
        foreach (var component in canvasComponents)
            component.enabled = true;


    }

//失去识别图后触发
    protected virtual void OnTrackingLost()
    {
        var rendererComponents = GetComponentsInChildren(true);
        var colliderComponents = GetComponentsInChildren(true);
        var canvasComponents = GetComponentsInChildren(true);

        // Disable rendering:
        foreach (var component in rendererComponents)
            component.enabled = false;

        // Disable colliders:
        foreach (var component in colliderComponents)
            component.enabled = false;

        // Disable canvas':
        foreach (var component in canvasComponents)
            component.enabled = false;

      
    }

    #endregion // PRIVATE_METHODS
}