音频无法在android设备中运行，但在Unity Editor中可以完美运行

Question

我是编程新手，我正在尝试向我的应用添加音频剪辑。 我使用了translate.google。我的目标是使用从Firebase数据库获得的String播放音频剪辑。该代码在Unity编辑器中有效，但在移动设备中无效。如何改善我的代码并在何处进行增强？这里是编程的新手。 ：D

    using Firebase;
using Firebase.Database;
using Firebase.Unity.Editor;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class dbfirebase : MonoBehaviour {
    FirebaseApp app;
    DatabaseReference reference;
    public AudioSource _audio;
    string message = "";
    [SerializeField]
    Text _text;
    // Use this for initialization
    void Start () {
        Firebase.FirebaseApp.CheckAndFixDependenciesAsync().ContinueWith(task => {
            var dependencyStatus = task.Result;
            if (dependencyStatus == Firebase.DependencyStatus.Available)
            {
                Debug.Log("Amazing!");
                firebase_init();
                reference = FirebaseDatabase.DefaultInstance.RootReference;
                _remarks();
                // Create and hold a reference to your FirebaseApp, i.e.
                //   app = Firebase.FirebaseApp.DefaultInstance;
                // where app is a Firebase.FirebaseApp property of your application class.

                // Set a flag here indicating that Firebase is ready to use by your
                // application.
            }
            else
            {
                Debug.LogError("dependencystatus sa else");
               // UnityEngine.Debug.LogError(System.String.Format(
                 // "Could not resolve all Firebase dependencies: {0}", dependencyStatus));
                // Firebase Unity SDK is not safe to use here.
            }
        });
    }

    IEnumerator DownloadTheAudio(string message)
    {
        string url = "https://translate.google.com/translate_tts?ie=UTF-8&total=1&idx=0&textlen=32&client=tw-ob&q=" + message + "&tl=En-gb";
        WWW www = new WWW(url);
        yield return www;

        _audio.clip = www.GetAudioClip(false, true, AudioType.MPEG);
        _audio.Play();
    }

    private void firebase_init()
    {
        app = FirebaseApp.DefaultInstance;
        // NOTE: You'll need to replace this url with your Firebase App's database
        // path in order for the database connection to work correctly in editor.
        app.SetEditorDatabaseUrl("https://userteameut.firebaseio.com/");
        if (app.Options.DatabaseUrl != null)
        {
            app.SetEditorDatabaseUrl(app.Options.DatabaseUrl);
        }
    }

    private void _remarks()
    {
        FirebaseDatabase.DefaultInstance
          .GetReference("ai_vhm/Black/white").Child("remarks")
          .GetValueAsync().ContinueWith(task => {
              if (task.IsFaulted)
              {
                  // Handle the error...
                  Debug.LogError("error error lagn");
                  }
              else if (task.IsCompleted)
              {
                  DataSnapshot snapshot = task.Result;
                  // Do something with snapshot...
                  message = snapshot.Value.ToString();


                  _text.text = message;

                  _audio = gameObject.GetComponent<AudioSource>();
                  StartCoroutine(DownloadTheAudio(message));

              }
          });
    }

    // Update is called once per frame
    void Update () {

    }
}