播放最大speakerPhone音量，然后使用AVAudioPlayer - IOS重置为上一个音量

Question

我已经能够将我的音频路由到speakerPhone，但是它仍然不能以最大音量播放。我尝试过audioAlert setVolume:1.0，它仍然保持在用户当前设置的音量。如果有人知道我做错了什么，我将不胜感激。

下面是我的代码：

AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:NULL];

    UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
    AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);

    NSURL* soundUrl = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"HsTR_soundEFX_2-1" ofType:@"mp3"]];
   audioAlert= [[AVAudioPlayer alloc] initWithContentsOfURL:soundUrl error:nil];
    audioAlert.delegate = self;
    [audioAlert setVolume:1.0];
    [audioAlert prepareToPlay];
    [audioAlert play];

感谢PaulPerry！

现在解决了：

我包含了一些额外的内容，以便使用下面的代码将其设置回以前的卷：

 AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:NULL];

    UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
    AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);

    NSURL* soundUrl = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"HsTR_soundEFX_2-1" ofType:@"mp3"]];
   audioAlert= [[AVAudioPlayer alloc] initWithContentsOfURL:soundUrl error:nil];
    audioAlert.delegate = self;
    [audioAlert prepareToPlay];
    float maxVolume = 1.0;
    float currentVolume=[MPMusicPlayerController applicationMusicPlayer].volume;
    [[MPMusicPlayerController applicationMusicPlayer] setVolume:maxVolume];
    [audioAlert play];
   //set up timer to wait until audioAlert is finished playing,
   // and then call the line below to set the volume back to it's original setting
    [[MPMusicPlayerController applicationMusicPlayer]setVolume:currentVolume];

Answer 1

这会将整个系统的音量重置为最大值。

浮动音量= 1.0；[MPMusicPlayerController applicationMusicPlayer设置音量:音量]；

Answer 2

不如先将其初始化为0，然后在[audioAlert prepareToPlay]将其设置回1之后：

[audioAlert prepareToPlay]
[audioAlert setVolume:1.0]