示例：

正確使用Unity官方提供的AndroidJavaClass呼叫android.provider.Settings中的屬性，以android_id為例

在unity中使用可以方便的呼叫到什麼androidid啦之類的，只要系統有寫就可以

    public string GetAndroidID()
    {
        string android_id = "NONE";
        try
        {
#if UNITY_ANDROID && !UNITY_EDITOR
            AndroidJavaClass up = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
            AndroidJavaObject currentActivity = up.GetStatic<AndroidJavaObject>("currentActivity");
            AndroidJavaObject contentResolver = currentActivity.Call<AndroidJavaObject>("getContentResolver");
            AndroidJavaClass secure = new AndroidJavaClass("android.provider.Settings$Secure");
             android_id = secure.CallStatic<string>("getString", contentResolver, "android_id");
#endif
        }
        catch (System.Exception e)
        {
            Debug.LogError(e);
        }

        return android_id;
    }