iphone - 如何使用滑块垂直移动 UILabel

Question

我想将我的滑块和我的拇指图像一起垂直移动。然而，搬家是错误的。

在水平它完美地工作但不是垂直

- (void)viewDidLoad
{
 CGAffineTransform trans = CGAffineTransformMakeRotation(-M_PI * 0.5);
 self.SDSlider.transform = trans;
}

- (IBAction)sliderValueChanged:(UISlider *)sender
{
    self.SDlabel.text = [NSString stringWithFormat:@"%d", (int)sender.value];

    CGRect trackRect = [self.SDSlider trackRectForBounds:self.SDSlider.bounds];
    CGRect thumbRect = [self.SDSlider thumbRectForBounds:self.SDSlider.bounds
                                             trackRect:trackRect
                                                 value:self.SDSlider.value];

    self.testSDlabel.center = CGPointMake(thumbRect.origin.x + self.SDSlider.frame.origin.x,  self.SDSlider.frame.origin.y - 20);
    self.testSDlabel.text = [NSString stringWithFormat:@"%.0f", self.SDSlider.value];  
}

标签从左向右移动，而不是从底部向上移动

Answer 1

Got 通过改变 center.y 值来工作

- (IBAction)sliderValueChanged:(UISlider *)sender
{
    self.SDlabel.text = [NSString stringWithFormat:@"%d", (int)sender.value];


    CGRect trackRect = [self.SDSlider trackRectForBounds:self.SDSlider.bounds];
    CGRect thumbRect = [self.SDSlider thumbRectForBounds:self.SDSlider.bounds
                                             trackRect:trackRect
                                                 value:self.SDSlider.value];

    self.SDlabel.text = [NSString stringWithFormat:@"%.0f", self.SDSlider.value];

    NSLog(@"thumbRect.origin.x %f",thumbRect.origin.x);
    NSLog(@"self.testSDlabel %f",self.SDlabel.center.x);    
    self.SDlabel.center = CGPointMake(self.SDlabel.center.x, 423 - thumbRect.origin.x);

}

Answer 2

首先将 viewdidLoad 中 label 的初始中心设置为

override func viewDidLoad() {
        super.viewDidLoad()
        initialLabelCenter = labelSliderValue.center.x
    }

    //Set value of slider into label from 100 to 1000
    @IBAction func sliderActionValueChanged(_ sender: UISlider) {
        let currentValue: CGFloat = CGFloat(sender.value)
        labelSliderValue.text = String(describing: currentValue)

        //Returns the drawing rectangle for the slider’s track
        let trackRect = sliderInstance.trackRect(forBounds: sliderInstance.bounds)

        //Returns the drawing rectangle for the slider’s thumb image.
        let sliderThumbRect = sliderInstance.thumbRect(forBounds: sliderInstance.bounds, trackRect: trackRect, value: sliderInstance.value)

        //Set label's center to move in a particular direction. In this case it will move left to right horizontally
        labelSliderValue.center = CGPoint(x: initialLabelCenter + sliderThumbRect.origin.x, y: self.labelSliderValue.center.y)
    }

注意：此代码从左到右水平移动标签。