투명 시스템 XAML에서 이러한 효과를 달성하는 방법 그라데이션 색 (WPF)

Question

: I가 0.0에서 1.0으로 각각 적절한 컬러 및 불투명 세트 두 브러쉬를 만들려고 한

<LinearGradientBrush x:Key="BrightSeparatorGradient" StartPoint="0.0, 0.5" EndPoint="1.0, 0.5"> 
     <GradientStop Offset="0.0" Color="{StaticResource {x:Static SystemColors.ControlLightColorKey}}" /> <!-- But fully transparent --> 
     <GradientStop Offset="0.5" Color="{StaticResource {x:Static SystemColors.ControlLightColorKey}}" /> 
     <GradientStop Offset="1.0" Color="{StaticResource {x:Static SystemColors.ControlLightColorKey}}" /> <!-- But fully transparent --> 
    </LinearGradientBrush> 

있지만 컴파일러는 브러시를 색상으로 취하지 않 았습니다 (두 번째 생각에서 꽤 논리가 무엇입니까 :)).

안부 인사 - Spook.

Answer 1

나는 Color를 받아 지정된 불투명도와 Color를 반환하는 MarkupExtension 만들 것입니다 :

public class OpacityExtension : MarkupExtension 
{ 
    private readonly Color color; 
    public byte Opacity { get; set; } // defaults to 0, so you don't have 
             // to set it for the color to be transparent 

    public OpacityExtension(Color color) 
    { 
     this.color = color;   
    } 

    public override object ProvideValue(IServiceProvider serviceProvider) 
    { 
     return Color.FromArgb(Opacity, color.R, color.G, color.B); 
    } 
} 

그리고 다음과 같이 사용 :

<LinearGradientBrush x:Key="BrightSeparatorGradient" StartPoint="0.0, 0.5" EndPoint="1.0, 0.5"> 
    <GradientStop Offset="0" Color="{lcl:Opacity {StaticResource {x:Static SystemColors.ControlLightColorKey}}}" /> 
    <GradientStop Offset=".5" Color="{StaticResource {x:Static SystemColors.ControlLightColorKey}}" /> 
    <GradientStop Offset="1" Color="{lcl:Opacity {StaticResource {x:Static SystemColors.ControlLightColorKey}}}" /> 
</LinearGradientBrush> 

Answer 2

놀래 킬을

다음 이유가 효과가없는 이유는 무엇입니까?

<LinearGradientBrush x:Key="BrightSeparatorGradient" StartPoint="0.0, 0.5" EndPoint="1.0, 0.5"> 
    <GradientStop Offset="0.0" Color="Transparent" /> 
    <GradientStop Offset="0.5" Color="{StaticResource {x:Static SystemColors.ControlLightColorKey}}" /> 
    <GradientStop Offset="1.0" Color="Transparent" /> 
</LinearGradientBrush>