24.调节系统声音最大,听筒和扬声器启动

1.#import <MediaPlayer/MediaPlayer.h>


-(void)makeVolumeOfSystemBig
{
    MPVolumeView *volumnView = [[MPVolumeView alloc]init];
    UISlider *volumeViewSlider = nil;
    for (UIView *view in volumnView.subviews) {
        if ([view.class.description isEqualToString:@"MPVolumeSlider"]) {
            volumeViewSlider = (UISlider *)view;
            break;
        }
    }
    [volumeViewSlider setValue:1.0f animated:NO];
    [volumeViewSlider sendActionsForControlEvents:(UIControlEventTouchUpInside)];

}

2.听筒和扬声器启动

  
//免提
-(void)registerAction:(UIButton *)sender
{
    //听筒打开
    if (sender.selected) {
        dispatch_async(dispatch_get_main_queue(), ^{
            [[AVAudioSession sharedInstance] overrideOutputAudioPort:AVAudioSessionPortOverrideNone error:nil];
        });
    }
    else //扬声器打开
    {
        dispatch_async(dispatch_get_main_queue(), ^{
            [[AVAudioSession sharedInstance] overrideOutputAudioPort:AVAudioSessionPortOverrideSpeaker error:nil];
        });
    }
    sender.selected = !sender.selected;
}