使用UISlider控制UIView动画持续时间？

Question

我试图用UISlider来控制UIView的动画持续时间。动画工作正常，并且运行时好像持续时间设置为1.0，但它不响应滑块。我有点新，所以非常感谢任何帮助。

@interface ViewController (){
    float number;
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [_slider setMinimumValue:0.5];
    [_slider setMaximumValue:1.0];
    [_slider setValue:0.5];

    number = _label.text.floatValue;

    _image.frame = 1

    [UIView animateWithDuration:number delay:0.1f options:UIViewAnimationOptionCurveLinear | UIViewKeyframeAnimationOptionAutoreverse | UIViewKeyframeAnimationOptionRepeat animations:^{
        _image.frame2;
    }
    completion:^(BOOL finished) {
        _image.frame1;
    }];
}

- (IBAction)sliderAction:(id)sender {
    _label.text = [NSString stringWithFormat:@"%f", _slider.value];
}

@end