IEnumerator DownloadMLModel()
    {
        string url      = "http://www.setsuodu.com/download/MobileNet.mlmodel"; //WWW不支持https
        string filePath = Application.persistentDataPath + "/MobileNet.mlmodel";

        if (!File.Exists(filePath))
        {
            Debug.Log("开始下载MLModel...");

            WWW www = new WWW(url);
            while (!www.isDone)
            {
                Debug.Log(www.progress * 100 + "%");
                yield return(null);
            }
            yield return(www);

            if (!string.IsNullOrEmpty(www.error))
            {
                Debug.Log(www.error);
                yield break;
            }

            if (www.isDone)
            {
                byte[]     bytes      = www.bytes;
                FileStream fileStream = File.Create(filePath);
                fileStream.Write(bytes, 0, bytes.Length);
                fileStream.Close();
            }
        }

        Debug.Log("下载完成:" + filePath);
        // /Users/xueyutao/Library/Application Support/setsuodu/CoreMLPlugin/MobileNet.mlmodel

        OSHookBridge.LoadMLModel(filePath);
    }