Contents

1. 工程结构
2. 基础类定义
1. 2.1. Android
2. 2.2. IOS
3. 插件调用模块
4. 插件实现
1. 4.1. Android
  1. 4.1.1. 基础类
  2. 4.1.2. 具体实现
2. 4.2. IOS
  1. 4.2.1. 定义接口
  2. 4.2.2. 具体实现

Unity作为跨平台的游戏引擎，支持很多跨平台的方法调用，但Unity重点还是在游戏开发，有些接口无法从Unity层面拿到，比如是设备全局音量控制接口、Android中的Activity跳转接口，本文通过实现设备全局音量控制这个功能，来介绍如何编写Unity移动端插件，PC端插件类似，这里就不再赘述

工程结构

Unity插件都是在对应平台编译好，打包成jar、动态库、静态库后，放在工程Assets/Plugin/Android、Assets/Plugin/IOS下面，Unity会自动把插件加载起来

基础类定义

Android

Unity调用Android接口可以是jar包，也可以是so文件，Unity提供调用Android接口方法很像Jni，下面通过GetUnityActivity()拿到当前App的Activity，这样插件可以基于这个Activity调用一些系统接口，GetJavaObject()方法相当于Jni中的JniEnv，用来调用对应插件的方法

public abstract class AndroidPluginBase {

	private const string UNITY_PLAYER_ANDROID_OBJECT_NAME = "com.unity3d.player.UnityPlayer";
	private const string UNITY_PLAYER_ACTIVITY_NAME = "currentActivity";

	protected abstract string getAndroidObjectEntryName ();

	private AndroidJavaObject javaObj = null;
	protected AndroidJavaObject GetJavaObject()
	{
		if (javaObj == null)
		{
			javaObj = new AndroidJavaObject(getAndroidObjectEntryName());
		}
		return javaObj;
	}

	protected AndroidJavaObject GetUnityActivity()
	{
		return new AndroidJavaClass(UNITY_PLAYER_ANDROID_OBJECT_NAME).GetStatic<AndroidJavaObject>(UNITY_PLAYER_ACTIVITY_NAME);
	}
}

IOS

IOS插件一般是以源文件的方式集成进来，通过Unity生成的xcode工程一起编译。GetRootControllerAddress()类似于Android里面获取Activity引用，插件拿到这个后可以调用IOS的一些方法

public class IOSPluginBase{


	[DllImport("__Internal")]
	private static extern long _getRootControllerAddress ();
	protected long GetRootControllerAddress()
	{
		return _getRootControllerAddress ();
	}

}

插件调用模块

插件要实现的接口

各个平台需要实现的接口

public interface IVolumeCtrlDevice{
	 float GetVolume ();
	 float SetVolume (float volume);
}

对Unity其他模块的接口

统一接口更加当前运行平台选择对应的插件实现，其中EditorVolumeCtrlDevice是一个空实现，保证在Editor状态下面可以编译通过

public class VolumeCtrlNative{

	private const string TAG = "VolumeCtrlNative";
	private IVolumeCtrlDevice volumeCtrlDevice;
	public VolumeCtrlNative()
	{
		#if UNITY_EDITOR
			volumeCtrlDevice = new EditorVolumeCtrlDevice();
		#elif UNITY_IPHONE
			volumeCtrlDevice = new IOSVolumeCtrlDevice();
		#elif UNITY_ANDROID
			volumeCtrlDevice = new AndroidVolumeCtrlDevice();
		#endif
	}

	public static VolumeCtrlNative INSTANCE{
		get {
			if (instance == null) {
				instance = new VolumeCtrlNative();
			}
			return instance;
		}
	}

	private static VolumeCtrlNative instance = null;

	public float GetVolume(){
		return volumeCtrlDevice.GetVolume ();
	}

	public float SetVolume(float volume){
		if (volume > 1.0 || volume < 0.0) {
			return -1.0f;
		}
		return volumeCtrlDevice.SetVolume (volume);
	}

}

Android

ANDROID_OBJECT_ENTRY_NAME表示插件的实现包名和类名，CallGetVolume()的实现跟Jni的调用很类似

public class AndroidVolumeCtrlDevice : AndroidPluginBase,IVolumeCtrlDevice
{
	private const string ANDROID_OBJECT_ENTRY_NAME = "com.yourcompany.VolumeCtrl";
	protected override string getAndroidObjectEntryName ()
	{
		return ANDROID_OBJECT_ENTRY_NAME;
	}

	public AndroidVolumeCtrlDevice()
	{
		CallSetUnityActivity();
	}

	public float GetVolume()
	{
		return CallGetVolume();
	}

	public float SetVolume(float volume)
	{
		return  CallSetVolume(volume);
	}

	private void CallSetUnityActivity()
	{
		GetJavaObject().Call("setUnityActivity", GetUnityActivity());
	}

	private float CallGetVolume()
	{
		return GetJavaObject().Call<float>("getVolume");
	}

	private float CallSetVolume(float volume)
	{
		return GetJavaObject().Call<float>("setVolume", volume);
	}
}

IOS

IOS的接口就是C#调用c方法的实现方式

public class IOSVolumeCtrlDevice : IOSPluginBase,IVolumeCtrlDevice {

	public IOSVolumeCtrlDevice()
	{
		SetRootControllerAddress();
	}

	[DllImport("__Internal")]
	private static extern float _media_player_volume_get_volume ();
	[DllImport("__Internal")]
	private static extern float _media_player_volume_set_volume (float volume);
	[DllImport("__Internal")]
	private static extern float _media_player_set_root_control(long rootControllerAddress);

	public float GetVolume()
	{
		return _media_player_volume_get_volume ();
	}

	public float SetVolume(float volume)
	{
		return _media_player_volume_set_volume (volume);
	}

	private void SetRootControllerAddress()
	{
		_media_player_set_root_control(GetRootControllerAddress ());
	}
}

插件实现

Android

基础类

public class BasePlugin {
    protected Activity activity;
    public void setUnityActivity(Activity activity) {
        this.activity = activity;
    }
}

具体实现

通过Unity传进来的Activity实例来调用系统方法获取全局音量

public class VolumeCtrl extends BasePlugin{

    private String TAG = this.getClass().getSimpleName();

    public float getVolume() {

        if (activity == null) {
            return;
        }

        AudioManager mgr = (AudioManager) activity.getSystemService(Context.AUDIO_SERVICE);
        final float MAX_STREAM_MUSIC_VOLUME = mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);

        float volume = mgr.getStreamVolume(AudioManager.STREAM_MUSIC);

        //change volume to 0.0 -> 1.0
        float normalizedVolume = volume / MAX_STREAM_MUSIC_VOLUME;
        return normalizedVolume;

    }

    public float setVolume(float volume) {

        Log.d(TAG, "setVolume volume " + volume);

        if (activity == null) {
            return -1.0f;
        }

        if (volume > 1.0f || volume < 0.0f) {
            return -1.0f;
        }

        AudioManager mgr = (AudioManager) activity.getSystemService(Context.AUDIO_SERVICE);
        final float MAX_STREAM_MUSIC_VOLUME = mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
        mgr.setStreamVolume(AudioManager.STREAM_MUSIC, (int) (volume * MAX_STREAM_MUSIC_VOLUME), 0);
        return volume;
    }

}

IOS

定义接口

@interface VolumeCtrl : NSObject

+ (VolumeCtrl*) getInstance;

- (int ) setRootController:(long)rootControllerAddress;
- (float) getVolume;
- (float) setVolume:(float)volume;
@end

具体实现

与Unity调用相关的接口通过extern “C”来定义，通过Unity传进来的rootController来呼出全局音量的组件

extern "C" {

    int _media_player_set_root_control(long rootControllerAddress) {
        return [[VolumeCtrl getInstance] setRootController:rootControllerAddress];
    }

    float _media_player_volume_get_volume() {
        return [[VolumeCtrl getInstance] getVolume];
    }

    float _media_player_volume_set_volume (float volume) {
        return [[VolumeCtrl getInstance] setVolume:volume];
    }
}

@interface VolumeCtrl ()
@property (nonatomic,strong)UISlider *slider;
@end

@implementation VolumeCtrl

static VolumeCtrl * instance;
+ (VolumeCtrl*) getInstance {
    @synchronized(self) {
        if(instance == nil) {
            instance = [[self alloc]init];
        }
    }
    return instance;
}
- (int ) setRootController:(long)rootControllerAddress
{

    UIViewController* rootViewController = (__bridge UIViewController *)((void*)rootControllerAddress);

    MPVolumeView *volumeView = [[MPVolumeView alloc] init];
    [rootViewController.view addSubview: volumeView];
    [volumeView sizeToFit];
    [rootViewController.view bringSubviewToFront: volumeView];

    _slider = [[UISlider alloc]init];
    _slider.backgroundColor = [UIColor blueColor];
    for (UIControl *view in volumeView.subviews) {
        if ([view.superclass isSubclassOfClass:[UISlider class]]) {
            self.slider = (UISlider *)view;
        }
    }
    _slider.autoresizesSubviews = NO;
    _slider.autoresizingMask = UIViewAutoresizingNone;
    volumeView.alpha = 0.001;

    return 0;
}

- (float) getVolume
{
    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    return audioSession.outputVolume;
}
- (float) setVolume:(float)volume
{
    assert(_slider != nil);
    _slider.value = volume;
    return _slider.value;
}

@end

Pengjun's Blog

Unity插件编写

工程结构

基础类定义

Android

IOS

插件调用模块

插件要实现的接口

对Unity其他模块的接口

Android

IOS

插件实现

Android

基础类

具体实现

IOS

定义接口

具体实现