IOS音量

��有时候有这样的需求进入某个界面音量调节到到最大, 离开界面音量恢复到之前的大小或者播放视频,音频文件时候将音量调节到最大, 播放完毕后恢复到原来的音量大小,程序控制改变  不显示系统音量调节的界面这里写一下进入应用音量调节到最大, 退出应用之后, 音量恢复到之前的大小在AppDelegate.m中导入#import声明

[objc] view plain copy

@property (nonatomic, strong) MPVolumeView *volumeView;

方法: 记录当前音量, 并将音量调节到最大

[objc] view plain copy

- (void)monitorVolume

{

//设置音量 为最大

MPMusicPlayerController *musicPlayer = [MPMusicPlayerController applicationMusicPlayer];

NSNumber *nowVolum = [NSNumber numberWithFloat:musicPlayer.volume];

NSLog(@"当前的音量是------%@",nowVolum);

[[NSUserDefaults standardUserDefaults] setObject:nowVolum forKey:@"nowVolum"];

//音量调节到最大

[self setVolume:1.0f];

}

- (void)setVolume: (float)value

{

if (!self.volumeView) {

self.volumeView = [[MPVolumeView alloc] init];

self.volumeView.frame = CGRectMake(0, 0, 200, 20);

self.volumeView.center = CGPointMake(-550,370);

[self.window addSubview:self.volumeView];

}

UISlider* volumeViewSlider = nil;

for (UIView *view in [self.volumeView subviews]){

if ([view.class.description isEqualToString:@"MPVolumeSlider"]){

volumeViewSlider = (UISlider*)view;

break;

}

}

self.volumeView.showsVolumeSlider = NO;

// change system volume, the value is between 0.0f and 1.0f

[volumeViewSlider setValue:value animated:NO];

// send UI control event to make the change effect right now.

[volumeViewSlider sendActionsForControlEvents:UIControlEventTouchUpInside];

[self.volumeView sizeToFit];

}

应用启动时候调节到最大

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

[self monitorVolume];

return YES;

}

应用退出的时候恢复到之前的大小

- (void)applicationWillTerminate:(UIApplication *)application

- {

NSNumber *oldVolume = [[NSUserDefaults standardUserDefaults] objectForKey:@"nowVolum"];

[self setVolume:[oldVolume floatValue]];

}