如何自定义MPVolumeView？

Question

我已经尝试了许多方法来实现常规UISlider和控制设备卷,但它是所有Native-C函数,导致许多无法追踪的错误.

我试过MPVolumeView它就像魅力一样,它甚至在你关闭应用程序后控制设备音量,就像iPod应用程序一样.

我的问题是,无论如何要定制MPVolumeView特定的颜色和图像,就像UISlider？

注意:我想要一个合法的方法,而不使用私有的未记录的API.

更新
根据@Alexsander Akers的回答,由于子视图隐藏在MPVolumeView我必须遍历子视图,获取UISlider并自定义它,这里是代码.

IBOutlet UISlider *volumeSlider;   //defined in <class.h> and connected to a UISlider in Interface Builder

-(void) viewDidLoad {
     ....
     [self setCustomSlider];
     ....
}

-(void) setCustomSlider{
     MPVolumeView *volumeView = [[[MPVolumeView alloc] initWithFrame:[volumeSlider frame]] autorelease];
     NSArray *tempArray = volumeView.subviews;

     for (id current in tempArray){
           if ([current isKindOfClass:[UISlider class]]){
                    UISlider *tempSlider = (UISlider *) current;
                    UIImage *img = [UIImage imageNamed:@"trackImage.png"];
                    img = [img stretchableImageWithLeftCapWidth:5.0 topCapHeight:0];
                    [tempSlider setMinimumTrackImage:img forState:UIControlStateNormal];

                    [tempSlider setThumbImage:[UIImage imageNamed:@"thumbImage.png"] forState:UIControlStateNormal];

           } 
    }
    [volumeSlider removeFromSuperview];
    [self.view addSubview:volumeView];
 }

Answer 1

您可以尝试在其子视图中循环并查找UISlider子类吗？

Answer 2

从iOS 5.0开始,您可以在UISlider上使用UIAppearance,即使是MPVolumeView的一部分.

代码库中的任何位置:

[[UISlider appearanceWhenContainedIn:[MPVolumeView class], nil] setMinimumTrackImage:[[UIImage imageNamed:@"nowplaying_bar_full.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(5, 25, 5, 25)] forState:UIControlStateNormal];
[[UISlider appearanceWhenContainedIn:[MPVolumeView class], nil] setMaximumTrackImage:[[UIImage imageNamed:@"nowplaying_bar_empty.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(5, 25, 5, 25)] forState:UIControlStateNormal];
[[UISlider appearanceWhenContainedIn:[MPVolumeView class], nil] setThumbImage:[UIImage imageNamed:@"nowplaying_player_nob.png"] forState:UIControlStateNormal];

这里列出了一些可以使用UIAppearance实现的其他类:https://gist.github.com/mattt/5135521