如何创建对象并在 Objective-C 中使用它？

Question

我正在为我的游戏使用 Buildbox。 我实施了自定义激励广告。 问题是当奖励视频打开时游戏音乐会继续。 我想在观看视频后静音和取消静音。

我知道 Java，但我不擅长 Objective-C 和 Cocos2dx。

我的AudioEngine.h类：在 libs/cocos2dx/include/audio/include/ 下

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#include "platform/CCPlatformConfig.h"

#ifndef __AUDIO_ENGINE_H_
#define __AUDIO_ENGINE_H_

#include <functional>
#include <list>
#include <string>
#include <unordered_map>

#include "platform/CCPlatformMacros.h"
#include "audio/include/Export.h"

#ifdef ERROR
#undef ERROR
#endif // ERROR

/**
 * @addtogroup audio
 * @{
 */

NS_CC_BEGIN
    namespace experimental{

/**
 * @class AudioProfile
 *
 * @brief
 * @js NA
 */
class CC_DLL AudioProfile
{
public:
    //Profile name can't be empty.
    std::string name;
    //The maximum number of simultaneous audio instance.
    unsigned int maxInstances;

    /* Minimum delay in between sounds */
    double minDelay;

    /**
     * Default constructor
     *
     * @lua new
     */
    AudioProfile()
    : maxInstances(0)
    , minDelay(0.0)
    {

    }
};

class AudioEngineImpl;

/**
 * @class AudioEngine
 *
 * @brief Offers a interface to play audio.
 *
 * @note Make sure to call AudioEngine::end() when the audio engine is not needed anymore to release resources.
 * @js NA
 */

class CC_DLL AudioEngine
{
public:
    /** AudioState enum,all possible states of an audio instance.*/
    enum class AudioState
    {
        ERROR  = -1,
        INITIALZING,
        PLAYING,
        PAUSED
    };

    static const int INVALID_AUDIO_ID;

    static const float TIME_UNKNOWN;

    static bool lazyInit();

    /**
     * Release objects relating to AudioEngine.
     *
     * @warning It must be called before the application exit.
     * @lua endToLua
     */
    static void end();

    /**  
     * Gets the default profile of audio instances.
     *
     * @return The default profile of audio instances.
     */
    static AudioProfile* getDefaultProfile();

    /** 
     * Play 2d sound.
     *
     * @param filePath The path of an audio file.
     * @param loop Whether audio instance loop or not.
     * @param volume Volume value (range from 0.0 to 1.0).
     * @param profile A profile for audio instance. When profile is not specified, default profile will be used.
     * @return An audio ID. It allows you to dynamically change the behavior of an audio instance on the fly.
     *
     * @see `AudioProfile`
     */
    static int play2d(const std::string& filePath, bool loop = false, float volume = 1.0f, const AudioProfile *profile = nullptr);

    /** 
     * Sets whether an audio instance loop or not.
     *
     * @param audioID An audioID returned by the play2d function.
     * @param loop Whether audio instance loop or not.
     */
    static void setLoop(int audioID, bool loop);

    /** 
     * Checks whether an audio instance is loop.
     *
     * @param audioID An audioID returned by the play2d function.
     * @return Whether or not an audio instance is loop.
     */
    static bool isLoop(int audioID);

    /** 
     * Sets volume for an audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     * @param volume Volume value (range from 0.0 to 1.0).
     */
    static void setVolume(int audioID, float volume);

    /** 
     * Gets the volume value of an audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     * @return Volume value (range from 0.0 to 1.0).
     */
    static float getVolume(int audioID);

    /** 
     * Pause an audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     */
    static void pause(int audioID);

    /** Pause all playing audio instances. */
    static void pauseAll();

    /** 
     * Resume an audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     */
    static void resume(int audioID);

    /** Resume all suspended audio instances. */
    static void resumeAll();

    /** 
     * Stop an audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     */
    static void stop(int audioID);

    /** Stop all audio instances. */
    static void stopAll();

    /**
     * Sets the current playback position of an audio instance.
     *
     * @param audioID   An audioID returned by the play2d function.
     * @param sec       The offset in seconds from the start to seek to.
     * @return 
     */
    static bool setCurrentTime(int audioID, float sec);

    /** 
     * Gets the current playback position of an audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     * @return The current playback position of an audio instance.
     */
    static float getCurrentTime(int audioID);

    /** 
     * Gets the duration of an audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     * @return The duration of an audio instance.
     */
    static float getDuration(int audioID);

    /** 
     * Returns the state of an audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     * @return The status of an audio instance.
     */
    static AudioState getState(int audioID);

    /** 
     * Register a callback to be invoked when an audio instance has completed playing.
     *
     * @param audioID An audioID returned by the play2d function.
     * @param callback
     */
    static void setFinishCallback(int audioID, const std::function<void(int,const std::string&)>& callback);

    /**
     * Gets the maximum number of simultaneous audio instance of AudioEngine.
     */
    static int getMaxAudioInstance() {return _maxInstances;}

    /**
     * Sets the maximum number of simultaneous audio instance for AudioEngine.
     *
     * @param maxInstances The maximum number of simultaneous audio instance.
     */
    static bool setMaxAudioInstance(int maxInstances);

    /** 
     * Uncache the audio data from internal buffer.
     * AudioEngine cache audio data on ios,mac, and win32 platform.
     *
     * @warning This can lead to stop related audio first.
     * @param filePath Audio file path.
     */
    static void uncache(const std::string& filePath);

    /** 
     * Uncache all audio data from internal buffer.
     *
     * @warning All audio will be stopped first.
     */
    static void uncacheAll();

    /**  
     * Gets the audio profile by id of audio instance.
     *
     * @param audioID An audioID returned by the play2d function.
     * @return The audio profile.
     */
    static AudioProfile* getProfile(int audioID);

    /**  
     * Gets an audio profile by name.
     *
     * @param profileName A name of audio profile.
     * @return The audio profile.
     */
    static AudioProfile* getProfile(const std::string &profileName);

    /**
     * Preload audio file.
     * @param filePath The file path of an audio.
     */
    static void preload(const std::string& filePath) { preload(filePath, nullptr); }

    /**
     * Preload audio file.
     * @param filePath The file path of an audio.
     * @param callback A callback which will be called after loading is finished.
     */
    static void preload(const std::string& filePath, std::function<void(bool isSuccess)> callback);

protected:
    static void addTask(const std::function<void()>& task);
    static void remove(int audioID);

    struct ProfileHelper
    {
        AudioProfile profile;

        std::list<int> audioIDs;

        double lastPlayTime;

        ProfileHelper()
            : lastPlayTime(0.0)
        {

        }
    };

    struct AudioInfo
    {
        const std::string* filePath;
        ProfileHelper* profileHelper;

        float volume;
        bool loop;
        float duration;
        AudioState state;

        AudioInfo()
            : profileHelper(nullptr)
            , duration(TIME_UNKNOWN)
            , state(AudioState::INITIALZING)
        {

        }
    };

    //audioID,audioAttribute
    static std::unordered_map<int, AudioInfo> _audioIDInfoMap;

    //audio file path,audio IDs
    static std::unordered_map<std::string,std::list<int>> _audioPathIDMap;

    //profileName,ProfileHelper
    static std::unordered_map<std::string, ProfileHelper> _audioPathProfileHelperMap;

    static unsigned int _maxInstances;

    static ProfileHelper* _defaultProfileHelper;

    static AudioEngineImpl* _audioEngineImpl;

    class AudioEngineThreadPool;
    static AudioEngineThreadPool* s_threadPool;

    friend class AudioEngineImpl;
};

}
NS_CC_END

// end group
/// @}

#endif // __AUDIO_ENGINE_H_

AdIntegrator 类。

    #import "AdIntegrator.h"
    #import <GoogleMobileAds/GoogleMobileAds.h>
    #import <UIKit/UIKit.h>
    #import "AppDelegate.h"
    #include "ads/PTAdController.h"
    #include "cocos2dx/include/audio/include/AudioEngine.h"



   @implementation AdIntegrator

    NSString *rewardedAdUnitId =@"ca-app-pub-0000000000/00000000";

    //Java equality : AudioEngine audio = new AudioEngine(); 


    + (id)shared{
        static AdIntegrator* integrator = nil;
        @synchronized(self){
            if(integrator == nil){
                integrator = [[self alloc] init];
            }
        }
        return integrator;
    }

    #pragma mark Core Methods

    - (void)initAds{
//Java Equality: audio.pauseAll();
        NSLog(@"[Ads] initialization");
        [GADRewardBasedVideoAd sharedInstance].delegate = self;
        [[GADRewardBasedVideoAd sharedInstance] loadRequest:[GADRequest request]
                                               withAdUnitID:rewardedAdUnitId];
    }



    #pragma mark Integration

    @end

如何在 Objective-C 中创建对象并使用它的方法？

Java 平等：

AudioEngine audio = new AudioEngine(); 

audio.pauseAll();

如何在 Objective-C 中执行此代码？

Answer 1

尝试使用以下代码对其进行初始化。

AudioEngine *audio = [[AudioEngine alloc] init];

您可以使用以下代码来调用其方法。

[audio pauseAll];

如果你有一些像 audio.abc.pausAll 这样的代码，那么你可以通过简单地添加 [] 来调用它。

例如

[[audio abc] pauseAll];

Answer 2

AudioEngine是一个 C++ 类。 您将从 Obj-C 调用 C++。 特别是， AudioEngine的方法是静态函数，因此没有要创建的“对象”。

您应该暂停和恢复，而不是静音和取消静音，因为静音会继续播放，只需将音量设置为 0。此外，根据您列出的AudioEngine标头中的功能，暂停更容易。 音量控制需要知道audioID ，这需要一些跟踪以确保所有播放的音频静音/取消静音。

当您想暂停时，只需调用：

experimental::AudioEngine::pauseAll();

要恢复，只需调用：

experimental::AudioEngine::resumeAll();

仅供参考，您可能还需要使用cocos2d命名空间。 这意味着experimental将更改为cocos2d::experimental 。

另一个警告是您的 Obj-C 代码必须编译为 Objective-C++ 源代码。

有两种方法可以做到这一点。

1. 源文件使用.mm扩展名。
2. 在 Xcode 的 File Inspector 中设置的文件类型明确设置为Objective-C++ Source 。 .m文件将被列为Objective-C Source 。 为此，请在 Project Navigator 中选择文件，然后在菜单中选择 View:Inspectors:Show File Inspector。 文件检查器（如果尚未出现）将显示在最右侧。

Answer 3

我解决了我的问题。 我可以使用以下方法在 AdIntegrator 类中静音和取消静音：

这将使所有声音静音。

PTAdController::shared()->setMusic(false);

这将取消所有声音的静音。

PTAdController::shared()->setMusic(true);