Xamarin窗体效果

我创建了一个效果来自定义xamarin窗体中的开关元素，但我在第15行发现了错误（指定的转换无效）。有什么想法来改变它？我班波纹管Xamarin窗体效果

using Android.Graphics; 
using Android.Widget; 
using Puuber.Droid.Platform; 
using Xamarin.Forms.Platform.Android; 


[assembly: Xamarin.Forms.ExportEffect(typeof(PinkSwitchEffect), "PinkSwitchEffect")] 
namespace Puuber.Droid.Platform 
{ 
class PinkSwitchEffect: PlatformEffect 
{ 
    protected override void OnAttached() 
    { 
     var toggle = (Android.Widget.Switch)Control; 
     Xamarin.Forms.Color gold = Xamarin.Forms.Color.FromHex("#fcb741"); 

     toggle.TrackDrawable.SetColorFilter(new PorterDuffColorFilter(gold.ToAndroid(), PorterDuff.Mode.SrcIn));  
    } 

    protected override void OnDetached() 
    { 
     // Use this method if you wish to reset the control to original state 
    } 
}

我的XAML文件是这样的，效果添加在XAML文件：

<?xml version="1.0" encoding="utf-8" ?> 
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" 
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
    xmlns:local="clr-namespace:Puuber;assembly=Puuber" 
    x:Class="Puuber.Welcome"> 
<AbsoluteLayout BackgroundColor="#161616"> 
<Image Source="logo.png" AbsoluteLayout.LayoutBounds="0.5 ,0, 1, 0.4" AbsoluteLayout.LayoutFlags="XProportional,YProportional,WidthProportional, HeightProportional"/> 
    <Label x:Name="rangeText" TextColor="#ffffff" FontSize = "24" Text="5 Km" HorizontalTextAlignment="End" AbsoluteLayout.LayoutBounds="0.8 ,0.5, 0.25, 0.1" AbsoluteLayout.LayoutFlags="XProportional,YProportional,WidthProportional, HeightProportional" local:CustomFontEffect.FontFileName="OpenSans-Regular"> 
     <Label.FontFamily> 
      <OnPlatform x:TypeArguments="x:String"> 
       <OnPlatform.Android></OnPlatform.Android> 
      </OnPlatform> 
     </Label.FontFamily> 
    </Label> 
    <Slider x:Name="rangeSlider" Maximum="100" Minimum="5" ValueChanged="rangeSlider_ValueChanged" AbsoluteLayout.LayoutBounds="0.5 ,0.55, 0.8, 0.1" AbsoluteLayout.LayoutFlags="XProportional,YProportional,WidthProportional, HeightProportional"> 
     <Slider.Effects> 
      <local:GoldSliderEffect/> 
     </Slider.Effects> 
    </Slider> 
    <Label Text="Mulheres" TextColor="#ffffff" FontSize = "24" HorizontalTextAlignment="Center" AbsoluteLayout.LayoutBounds="0.5 ,0.7, 0.5, 0.1" AbsoluteLayout.LayoutFlags="XProportional,YProportional,WidthProportional, HeightProportional" local:CustomFontEffect.FontFileName="OpenSans-Regular"> 
     <Label.FontFamily> 
      <OnPlatform x:TypeArguments="x:String"> 
       <OnPlatform.Android></OnPlatform.Android> 
      </OnPlatform> 
     </Label.FontFamily> 
    </Label> 
<Switch IsToggled="{Binding isOn}" AbsoluteLayout.LayoutBounds="0.8 ,0.667, 0.15, 0.05" AbsoluteLayout.LayoutFlags="XProportional, YProportional, WidthProportional, HeightProportional"> 
    <Switch.Effects> 
      <local:PinkSwitchEffect/> 
     </Switch.Effects> 
</Switch> 
    <Label Text="Homens" TextColor="#ffffff" FontSize = "24" HorizontalTextAlignment="Center" AbsoluteLayout.LayoutBounds="0.5 ,0.80, 0.5, 0.1" AbsoluteLayout.LayoutFlags="XProportional,YProportional,WidthProportional, HeightProportional" local:CustomFontEffect.FontFileName="OpenSans-Regular"> 
     <Label.FontFamily> 
      <OnPlatform x:TypeArguments="x:String"> 
       <OnPlatform.Android></OnPlatform.Android> 
      </OnPlatform> 
     </Label.FontFamily> 
    </Label> 
<Switch IsToggled="{Binding isOn}" AbsoluteLayout.LayoutBounds="0.8 ,0.767, 0.15, 0.05" AbsoluteLayout.LayoutFlags="XProportional, YProportional, WidthProportional, HeightProportional"/> 
<Label Text="Travestis" TextColor="#ffffff" FontSize = "24" HorizontalTextAlignment="Center" AbsoluteLayout.LayoutBounds="0.5 ,0.9, 0.5, 0.1" AbsoluteLayout.LayoutFlags="XProportional,YProportional,WidthProportional, HeightProportional" local:CustomFontEffect.FontFileName="OpenSans-Regular"> 
     <Label.FontFamily> 
      <OnPlatform x:TypeArguments="x:String"> 
       <OnPlatform.Android></OnPlatform.Android> 
      </OnPlatform> 
     </Label.FontFamily> 
    </Label> 
    <Switch IsToggled="{Binding isOn}" AbsoluteLayout.LayoutBounds="0.8 ,0.867, 0.15, 0.05" AbsoluteLayout.LayoutFlags="XProportional, YProportional, WidthProportional, HeightProportional"/> 
</AbsoluteLayout> 
</ContentPage>

来源

2016-11-08 Vinicius César

你能否把包含效果的代码放在控件中？ – matthewrdev

立即使用xaml文件编辑。 –

可能是你Control将是Android.Support.V7.Widget.SwitchCompat而不是Android.Widget.Switch一个实例。默认情况下，当您启动新的Xamarin Forms项目时，Android MainActivity从global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity继承。在这种情况下，XAML Switch将变为SwitchCompat而不是Android.Widget.Switch。

您可以通过查看Visual Studio或Xamarin Studio中的检查器来了解Control的类型。因此，如果Control的类型为SwitchCompat，则将第15行更改为var toggle = (Android.Support.V7.Widget.SwitchCompat)Control;。

既然你到了错误，我希望你已经做以下，但为了完成：

请记住，你需要在你的Android项目ResolutionGroupName装配属性和RoutingEffect在PCL /共享项目，以便正确引用效果。有关此示例，请参见https://developer.xamarin.com/guides/xamarin-forms/application-fundamentals/effects/creating/。

以供参考，这是Android的渲染器创建为本地控制的基础上，在MainActivity基类：

FormsApplicationActivity：https://github.com/xamarin/Xamarin.Forms/blob/master/Xamarin.Forms.Platform.Android/Renderers/SwitchRenderer.cs#L52
FormsAppCompatActivity：https://github.com/xamarin/Xamarin.Forms/blob/master/Xamarin.Forms.Platform.Android/AppCompat/SwitchRenderer.cs#L41

来源

2017-04-26 22:14:02

Xamarin窗体效果

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