如何切换MutableRuntimeReferenceImageLibrary？切换后追踪事件未更新

我通过以下函数切换AR参考库，日志显示库切换成功、标记已添加，但后续trackedImagesChanged事件完全没有触发，无法追踪新库中的标记：

public void switchImageLibrary(int curLibIndex)
{
    trackImageManager.trackedImagesChanged -= OnTrackedImagesChanged;
    var newLib = curLibIndex == 0 ? "QR Library" : "Image Library";
    LogHandler.Instance.Log("Switching Library to :- " + newLib);
    trackImageManager.enabled = false;
    var lib = curLibIndex == 0 ? QRCodeImageLibrary : ImageAccessPointLibrary;
    trackImageManager.referenceLibrary = trackImageManager.CreateRuntimeLibrary(lib) as MutableRuntimeReferenceImageLibrary;
    trackImageManager.enabled = true;
    trackImageManager.trackedImagesChanged += OnTrackedImagesChanged;
    LogHandler.Instance.Log("Current Marker Count : " + trackImageManager.referenceLibrary.count);
    LogHandler.Instance.Log("Current Library name " + trackImageManager.referenceLibrary.ToString());

    for (int i = 0; i < trackImageManager.referenceLibrary.count; i++) {
        LogHandler.Instance.Log("Reference Added In Library : " + trackImageManager.referenceLibrary[i].name);
    }
}

排查与修复方案 #

• 调整事件订阅时机：将事件订阅移至trackImageManager.enabled = true之前，避免错过组件启用时的初始化事件：

  trackImageManager.trackedImagesChanged += OnTrackedImagesChanged;
  trackImageManager.enabled = true;
  

• 强制重置AR追踪状态：切换库后清除旧追踪数据并重启会话，确保新库标记能被重新检测：

  // 清除已追踪的旧图像对象
  foreach (var trackedImage in trackImageManager.trackables)
  {
      trackedImage.gameObject.SetActive(false);
  }
  // 重启AR会话以刷新检测逻辑
  if (ARSession.state != ARSessionState.None)
  {
      ARSession.Restart();
  }
  

• 验证RuntimeLibrary实例有效性：添加空值检查，避免类型转换失败导致库切换无效：

  var newRuntimeLib = trackImageManager.CreateRuntimeLibrary(lib) as MutableRuntimeReferenceImageLibrary;
  if (newRuntimeLib == null)
  {
      LogHandler.Instance.LogError("Failed to create valid runtime reference library!");
      return;
  }
  trackImageManager.referenceLibrary = newRuntimeLib;
  

• 检查ARSession运行状态：确保切换库时AR会话未处于暂停或错误状态，若会话异常需先恢复再执行切换逻辑。

内容的提问来源于stack exchange，提问作者Hardik