Unity 调用 Android Native 方法(一) 获得Android系统音量

学习雷锋，好榜样，接下来的这一系类教程里，将通过unity来实现Android端的一些常用功能，

不需要在 Asset/Plugins/Android 目录下引用jar包或者aar包，这是重点。

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;

 public class Volume : MonoBehaviour {

     private const string currentVolume = "getStreamVolume";//当前音量
     private const string maxVolume = "getStreamMaxVolume";//最大音量

     private const int STREAM_VOICE_CALL = ;
     private const int STREAM_SYSTEM = ;
     private const int STREAM_RING = ;
     private const int STREAM_MUSIC = ;
     private const int STREAM_ALARM = ;
     private const int STREAM_NOTIFICATION = ;
      const int STREAM_DTMF = ;

     //创建几个 "3D Text" 用于接收音量值
     public  TextMesh STREAM_VOICE_CALL_Text;
     public  TextMesh STREAM_SYSTEM_Text;
     public  TextMesh STREAM_RING_Text;
     public  TextMesh STREAM_MUSIC_Text;
     public  TextMesh STREAM_ALARM_Text;
     public  TextMesh STREAM_NOTIFICATION_Text;
     public  TextMesh STREAM_DTMF_Text;

     private static AndroidJavaObject audioManager;

     void Awake()
     {
         AndroidJavaClass UnityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
         AndroidJavaObject currentActivity = UnityPlayer.GetStatic<AndroidJavaObject>("currentActivity");
         audioManager = currentActivity.Call<AndroidJavaObject>("getSystemService", new AndroidJavaObject("java.lang.String", "audio"));
     }
     void Update()
     {
 //        //current volume value
 //        STREAM_VOICE_CALL_Text.text = audioManager.Call<int> (currentVolume, STREAM_VOICE_CALL).ToString ();
 //        STREAM_SYSTEM_Text.text = audioManager.Call<int> (currentVolume, STREAM_SYSTEM).ToString ();
 //        STREAM_RING_Text.text = audioManager.Call<int> (currentVolume, STREAM_RING).ToString ();
 //        STREAM_MUSIC_Text.text = audioManager.Call<int> (currentVolume, STREAM_MUSIC).ToString ();
 //        STREAM_ALARM_Text.text = audioManager.Call<int> (currentVolume, STREAM_ALARM).ToString ();
 //        STREAM_NOTIFICATION_Text.text = audioManager.Call<int> (currentVolume, STREAM_NOTIFICATION).ToString ();
 //        STREAM_DTMF_Text.text = audioManager.Call<int> (currentVolume, STREAM_DTMF).ToString ();

         //Max volume value
         STREAM_VOICE_CALL_Text.text = audioManager.Call<int> (maxVolume, STREAM_VOICE_CALL).ToString ();
         STREAM_SYSTEM_Text.text = audioManager.Call<int> (maxVolume, STREAM_SYSTEM).ToString ();
         STREAM_RING_Text.text = audioManager.Call<int> (maxVolume, STREAM_RING).ToString ();
         STREAM_MUSIC_Text.text = audioManager.Call<int> (maxVolume, STREAM_MUSIC).ToString ();
         STREAM_ALARM_Text.text = audioManager.Call<int> (maxVolume, STREAM_ALARM).ToString ();
         STREAM_NOTIFICATION_Text.text = audioManager.Call<int> (maxVolume, STREAM_NOTIFICATION).ToString ();
         STREAM_DTMF_Text.text = audioManager.Call<int> (maxVolume, STREAM_DTMF).ToString ();

     }
 }