控制系统音量,自己定义MPVolumeView

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近期有一个需求,就是控制系统的音量,我们都知道原理在mediaPlayer.framework框架下,有方法

<span style="font-size:18px;">// The current volume of playing music, in the range of 0.0 to 1.0.

// This property is deprecated -- use MPVolumeView for volume control instead.

@property(nonatomic) float volume NS_DEPRECATED_IOS(3_0, 7_0);

[[MPMusicPlayerController applicationMusicPlayer] setVolume:self.volumeSlider.value];</span>

但实际上,在ios7以后,就被弃用了,官方的说法是希望我们用MPVolumeView来取代.那么好,如今有一个问题是,MPVolumeView非常难自己定义,他仅仅能自己定义一些图片,假设我们想通过手势来上下来控制音量大小怎么做呢?

<span style="font-size:18px;">MPVolumeView *volumeView = [[MPVolumeView alloc] init];

    [self.view addSubview:volumeView];

    [volumeView sizeToFit];

    NSLog(@"%@",volumeView.subviews);</span>

打印他的subViews,你会发现

有一个叫MPVolumeSlider得类,那么我们仅仅要能控制这个类即可了,但是假设我们强制创建这个类是无法实现的,但是没关系,他的baseClass是UISlider我们能够通过这样的方法实现

<span style="font-size:18px;">self.slider = [[UISlider alloc]init];

    self.slider.backgroundColor = [UIColor blueColor];

    for (UIControl *view in volumeView.subviews) {

        if ([view.superclass isSubclassOfClass:[UISlider class]]) {

            NSLog(@"1");

            self.slider = (UISlider *)view;

        }

    }

    self.slider.autoresizesSubviews = NO;

    self.slider.autoresizingMask = UIViewAutoresizingNone;

    [self.view addSubview:self.slider];

</span>

这个时候还会发现一个问题就是,他的frame是(0,0,35,34),那么你会发现你等于的slider永远都在屏幕的左上角,这个问题我的处理方式是直接hidden = yes,然后又一次在建立一个slider与他的值进行关联,然后重写touch事件,这样就能够直接通过手势来控制了.以下是完整代码

<span style="font-size:18px;">

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic,strong)UISlider *volumeSlider;

@property (nonatomic,strong)UISlider *slider;

@property (nonatomic,assign)CGPoint firstPoint;

@property (nonatomic,assign)CGPoint secondPoint;

@end

@implementation ViewController

- (void)viewDidLoad

{

    [super viewDidLoad];

	// Do any additional setup after loading the view, typically from a nib.

    MPVolumeView *volumeView = [[MPVolumeView alloc] init];

    [self.view addSubview:volumeView];

    [volumeView sizeToFit];

    NSLog(@"%@",volumeView.subviews);

    self.slider = [[UISlider alloc]init];

    self.slider.backgroundColor = [UIColor blueColor];

    for (UIControl *view in volumeView.subviews) {

        if ([view.superclass isSubclassOfClass:[UISlider class]]) {

            NSLog(@"1");

            self.slider = (UISlider *)view;

        }

    }

    self.slider.autoresizesSubviews = NO;

    self.slider.autoresizingMask = UIViewAutoresizingNone;

    [self.view addSubview:self.slider];

    self.slider.hidden = YES;

    NSLog(@"%f",self.slider.value);

//    UISlider *slider =

//    self.volumeSlider = [[UISlider alloc]initWithFrame:CGRectMake(100, 100, 200, 100)];

//    self.volumeSlider.backgroundColor = [UIColor yellowColor];

//    self.volumeSlider.minimumValue = 0.0;

//    self.volumeSlider.maximumValue = 1.0;

//    self.volumeSlider.continuous = YES;

//    [self.volumeSlider addTarget:self action:@selector(volumeChange) forControlEvents:UIControlEventValueChanged];

//    [self.view addSubview:self.volumeSlider];

    UISlider *slider1 = [[UISlider alloc] initWithFrame:CGRectMake(0, 100, 200, 20)];

    slider1.tag = 1000;

    slider1.minimumValue = self.slider.minimumValue;

    slider1.maximumValue = self.slider.maximumValue;

    slider1.value = self.slider.value;

    [slider1 addTarget:self action:@selector(updateValue:) forControlEvents:UIControlEventValueChanged];

    [self.view addSubview:slider1];

}

- (void)updateValue:(UISlider *)slider{

    self.slider.value = slider.value;

}

- (void)volumeChange

{

    [[MPMusicPlayerController applicationMusicPlayer] setVolume:self.volumeSlider.value];

}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

    for(UITouch *touch in event.allTouches) {

        self.firstPoint = [touch locationInView:self.view];

    }

    UISlider *slider = (UISlider *)[self.view viewWithTag:1000];

    slider.value = self.slider.value;

    NSLog(@"touchesBegan");

}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{

    for(UITouch *touch in event.allTouches) {

        self.secondPoint = [touch locationInView:self.view];

    }

    NSLog(@"firstPoint==%f || secondPoint===%f",self.firstPoint.y,self.secondPoint.y);

    NSLog(@"first-second==%f",self.firstPoint.y - self.secondPoint.y);

    self.slider.value += (self.firstPoint.y - self.secondPoint.y)/500.0;

    UISlider *slider = (UISlider *)[self.view viewWithTag:1000];

    slider.value = self.slider.value;

    NSLog(@"value == %f",self.slider.value);

    self.firstPoint = self.secondPoint;

}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{

    NSLog(@"touchesEnded");

    self.firstPoint = self.secondPoint = CGPointZero;

}

</span>