使用UISlider移动两个UIImageView

Question

我正在尝试按照UISlider将两个UIImageView移动到一起。这是一张更好理解的图片：

当滑块的球滑到最左侧（值为零）时，只显示绿色。当它滑到最右边（值为600）时，只显示红色。如果滑块的值为480，则应显示红色图片的80％和绿色的20％。我用来尝试实现这个的代码：

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.slider.minimumValue = 0;
    self.slider.maximumValue = 600;
}

- (IBAction)sliderChanged:(id)sender {

    [imageViewLeft setFrame:CGRectMake(slider.value - 50, imageViewLeft.frame.origin.y,imageViewLeft.frame.size.width,imageViewLeft.frame.size.height)];

        [imageViewRight setFrame:CGRectMake(slider.value + 50, imageViewRight.frame.origin.y,imageViewRight.frame.size.width,imageViewRight.frame.size.height)];

}

这是正常工作，但第二次更改滑块，红色图像（名为imageViewLeft）缩小，而imageViewRight保持相同的大小。我不能为我的生活弄清楚为什么（我仍然非常新的编程和iOS一般）。有谁知道我应该改变什么或如何最好地完成这个？

Answer 1

通过将绿色背景保持为全屏并仅调整红色视图，您可以实现更多或更少相同的功能：

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.slider.minimumValue = 0;
    self.slider.maximumValue = 600;

    imageViewRight.frame = self.view.bounds;
}

- (IBAction)sliderChanged:(id)sender {
    [imageViewLeft setFrame:CGRectMake(0, 0,(self.slider.value/self.slider.maximumValue)*sliderimageViewRight.frame.size.width,imageViewRight.frame.size.height)];
}

或者，如果你仍然希望边缘到边缘都有两种观点，那么你可以这样做：

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.slider.minimumValue = 0;
    self.slider.maximumValue = 600;
}

- (IBAction)sliderChanged:(id)sender {
    [imageViewLeft setFrame:CGRectMake(0, 0,(self.slider.value/self.slider.maximumValue)*self.view.bounds.size.width,self.view.bounds.size.height)];
    [imageViewRight setFrame:CGRectMake(imageViewLeft.frame.size.width, 0,self.view.bounds.size.width-imageViewLeft.frame.size.width,self.view.bounds.size.height)];
}

Answer 2

[self.red setFrame:CGRectMake(slider.value+50-self.view.frame.size.width, imageViewLeft.frame.origin.y,self.view.frame.size.width, imageViewLeft.frame.size.height)];
[self.green setFrame:CGRectMake(slider.value+50, imageViewRight.frame.origin.y,self.view.frame.size.width, imageViewRight.frame.size.height)];

并将最大滑块值设置为其宽度：

self.slider.maximumValue = self.slider.frame.size.width;