UI基础 - UISlider | UIImageView

■ 简言

1. UISlider 是滑块控件，它提供了一系列连续的值，滑块停在不同的位置，获取到滑块上的值也不同。常用于控制视频播放进度、控制⾳音量等

■ 使用方式 

1. 通过控拖动滑块改变图片的播放速度

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor blackColor];
    
    // ---------------- UIImageView ------------------
    NSMutableArray *imagesArray = [NSMutableArray arrayWithCapacity:0];
    for (int i = 1; i < 9; i ++) {
        UIImage *aImage = [UIImage imageNamed:[NSString stringWithFormat:@"phenix_%d.tiff",i]];
        [imagesArray addObject:aImage];
    }
    
    // imageView 相当于一个相框，专门用作显示图片，可以存放一个图片或一组图片
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(20, 50, self.view.frame.size.width - 40, self.view.frame.size.width - 100)];
    imageView.animationImages = imagesArray;
    imageView.layer.cornerRadius = 5;
    imageView.layer.masksToBounds = YES;
    imageView.animationDuration = 0.8;// 播放速度
    imageView.tag = 108;
    // imageView.animationRepeatCount = 10; // 重复次数
    [imageView startAnimating];// 开启动画
    [self.view addSubview:imageView];
    
    //  ---------------- UISlider  ----------------
    UISlider *slider = [[UISlider alloc] initWithFrame:CGRectMake(10, self.view.frame.size.width, self.view.frame.size.width - 20, 10)];
    // 轨道的颜色
    slider.minimumTrackTintColor = [UIColor redColor];  // 左
    slider.maximumTrackTintColor = [UIColor greenColor];// 右
    // 默认 0 - 1
    slider.minimumValue = 0.1;// 最大值
    slider.maximumValue = 1.0;// 最小值
    slider.thumbTintColor = [UIColor yellowColor];// 滑块颜色
    // 修改滑块大小：需使用到自定义方法 OriginImage: scaleToSize:
    // 滑块大小系统默认为图片原始大小且无法直接修改
    UIImage *image1 = [self OriginImage:[UIImage imageNamed:@"action1"] scaleToSize:CGSizeMake(45, 45)];
    UIImage *image2 = [self OriginImage:[UIImage imageNamed:@"action2"] scaleToSize:CGSizeMake(45, 45)];
    
    [slider setThumbImage:image1 forState:UIControlStateNormal];
    [slider setThumbImage:image2 forState:UIControlStateHighlighted];
    [slider addTarget:self action:@selector(changeSlider:) forControlEvents:UIControlEventValueChanged];
    slider.continuous = YES;// 默认 YES：滑动的过程中持续调用 changeSlider 方法，NO 则是在滑动结束后调用
    [self.view addSubview:slider];
    
}

// 更改滑块尺寸
- (UIImage *)OriginImage:(UIImage*)image scaleToSize:(CGSize)size{
    // size 为 CGSize 类型，即你所需要的图片尺寸
    UIGraphicsBeginImageContext(size);
    [image drawInRect:CGRectMake(0,0, size.width, size.height)];
    UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return scaledImage;
}

// 控制动图快慢
- (void)changeSlider:(UISlider *)slider{
    
    UIImageView *imageView = (UIImageView *) [self.view viewWithTag:108];
    NSLog(@"slider.maximumValue = %.2f；slider.minimumValue = %.2f",slider.maximumValue,slider.minimumValue);
    imageView.animationDuration = slider.maximumValue - slider.value;
    [imageView startAnimating];
    NSLog(@"slider.value = %.2f",slider.value);
    if (slider.value - 1 == 0) {
        // 关闭动画
        [imageView stopAnimating];
    }
}

运行效果