Unity 調用 Android Native 方法(一) 獲得Android系統音量

學習雷鋒，好榜樣，接下來的這一系類教程里，將通過unity來實現Android端的一些常用功能，

不需要在 Asset/Plugins/Android 目錄下引用jar包或者aar包，這是重點。

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

public class Volume : MonoBehaviour {


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

    private const int STREAM_VOICE_CALL = 0;
    private const int STREAM_SYSTEM = 1;
    private const int STREAM_RING = 2;
    private const int STREAM_MUSIC = 3;
    private const int STREAM_ALARM = 4;
    private const int STREAM_NOTIFICATION = 5;
     const int STREAM_DTMF = 8;

    //創建幾個 "3D Text" 用於接收音量值
    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 ();

    }
}