UISlider在iOS App中增加了滑块尺寸但没有拇指扭曲

Question

我需要增加使用iOS app创建的Xamarin Forms中滑块的大小。我尝试使用以下自定义渲染器覆盖 LayoutSubviews 。它增加了尺寸，但拇指的尺寸增加是不可接受的。如何减小拇指的大小，保持滑块的高度增加？

在Android中可以显示：Increase height of slider without affecting thumb in Android App

iOS参考：

1. Custom UISlider - Increase "hot spot" size

2. Increasing a thumbs "click area" in UISlider

C＃自定义渲染器

[assembly: ExportRenderer(typeof(MySlider), typeof(MySliderRenderer))]
namespace CustomRenderer.iOS
{
    class MySliderRenderer : Xamarin.Forms.Platform.iOS.SliderRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<Slider> e)
        {
            base.OnElementChanged(e);   
            Control.MinimumTrackTintColor = UIColor.FromRGB(0xE6, 0x00, 0x06);
            Control.ThumbTintColor = UIColor.Red;
            Control.MinimumTrackTintColor = UIColor.Orange;
            Control.MaximumTrackTintColor = UIColor.Yellow;
            //Control.SetThumbImage(UIImage.FromFile("myicon.png"), UIControlState.Normal);
        }

        public override void LayoutSubviews()
        {
            base.LayoutSubviews();
            CGAffineTransform transform = CGAffineTransform.MakeScale(1f, 12.0f);
            transform.TransformSize(this.Frame.Size);
            this.Control.Transform = transform;            
        }
    }
}



更新 - 参考 - 渲染器

1. Customizing Control Rendering in Xamarin.Forms

2. Implementing a View - Rendering a platform-specific view

3. iOS range slider for Xamarin and Xamarin.Forms

4. Fullscreen Video Background Control for Xamarin.Forms

Answer 1

覆盖TrackRectForBounds以更改其高度，而不是更改transform。

在MySliderRenderer中

class MySliderRenderer : SliderRenderer
{
    protected override void OnElementChanged(ElementChangedEventArgs<Slider> e)
    {
        SetNativeControl(new MySlideriOS());
        base.OnElementChanged(e);
    }
}

创建UISlider的子类

public class MySlideriOS : UISlider
{
    public MySlideriOS() {
        this.MinimumTrackTintColor = UIColor.FromRGB(0xE6, 0x00, 0x06);
        this.ThumbTintColor = UIColor.Red;
        this.MinimumTrackTintColor = UIColor.Orange;
        this.MaximumTrackTintColor = UIColor.Yellow;
    }

    public override CGRect TrackRectForBounds(CGRect forBounds)
    {
        CGRect rect =  base.TrackRectForBounds(forBounds);
        return new CGRect(rect.X, rect.Y, rect.Width, 20);
    }
}

我的测试

这是Sample