如何在iOS中以编程方式创建和显示UISlider？

Question

我在Apple文档中找到了下面的代码,并将其添加到我的viewDidLoad方法中,但是当我运行代码时,滑块不会出现.

CGRect frame = CGRectMake(0.0, 0.0, 200.0, 10.0);
UISlider *slider = [[UISlider alloc] initWithFrame:frame];
[slider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventValueChanged];
[slider setBackgroundColor:[UIColor clearColor]];
slider.minimumValue = 0.0;
slider.maximumValue = 50.0;
slider.continuous = YES;
slider.value = 25.0;

Answer 1

您需要将滑块添加到视图层次结构中.添加[self.view addSubview:slider];,它应该工作.

Answer 2

试试这个代码:

创建一个新滑块

-(IBAction)mySlider
{ 
    CGRect frame = CGRectMake(0.0, 0.0, 200.0, 10.0);
    UISlider *slider = [[UISlider alloc] initWithFrame:frame];
    [slider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventValueChanged];
    [slider setBackgroundColor:[UIColor clearColor]];
    slider.minimumValue = 0.0;
    slider.maximumValue = 50.0;
    slider.continuous = YES;
    slider.value = 25.0;
    [self.view addSubview:slider];
}

滑块动作

-(void)sliderAction:(id)sender
{
    UISlider *slider = (UISlider*)sender;
    float value = slider.value;
    //-- Do further actions
}