更改IOS Xamarin表单中的开关颜色 [英] Change Switch color in IOS Xamarin Forms

问题描述

切换IOS Xamarin Forms时如何更改切换按钮的颜色?自定义渲染将只设置一次颜色:

How to change the color of the switch button when toggling for IOS Xamarin Forms? Custom render will set the color just once:

Xamarin表单在IOS上的切换按钮默认颜色

，切换开关时不会更改.同样，在AppDelegate.cs中设置值仅会执行一次.我需要这个:

and it won't be changed when the Switch is toggled. Same goes and for setting values in AppDelegate.cs it will be done only once. I need this:

在IOS中，只能使用:

In IOS its only possible using:

UISwitch.Appearance.ThumbTintColor = UIColor.Brown;
UISwitch.Appearance.OnTintColor = UIColor.Red;

但是，如果我的开关在PCL项目中，并且Xamarin Forms用于Xamarin Forms，我将如何访问该字段.

but how I can access that field if my switch is in PCL project, and its used for Xamarin Forms.

推荐答案

我用以下方法解决了这个问题:

I solved this with:

public class CustomSwitchRenderer: SwitchRenderer
{       
    protected override void OnElementChanged(ElementChangedEventArgs<Switch> e)
    {
        Element.Toggled += ElementToggled;

        base.OnElementChanged(e);

        if (Control != null)
        {                
            UpdateUiSwitchColor();
        }
    }

    private void ElementToggled(object sender, ToggledEventArgs e)
    {
        UpdateUiSwitchColor();
    }

    private void UpdateUiSwitchColor()
    {
        var temp = Element as Switch;

        if (temp.IsToggled)
        {
            Control.ThumbTintColor = Color.FromHex(ColorConstants.BlueHex).ToUIColor();
            Control.OnTintColor = Color.FromHex(ColorConstants.OblueLightHex).ToUIColor();
        }
        else
        {
            Control.ThumbTintColor =  Color.FromHex(ColorConstants.GrayHex).ToUIColor();
        }
    }
}

因此，无论何时执行Toggle，我都会激活事件:

So, I activated event whenever Toggle is executed:

Element.Toggled += ElementToggled;

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