我正在使用 .net 4,vs2010 并创建了一个用户控件,该控件需要开始折叠和透明(不透明度 0)并响应按钮单击而变得可见和不透明。
<UserControl x:Class="Ihi.LeadRetrieval.Client.Views.HelpView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid x:Name="HelpGrid" Visibility="Collapsed" Opacity="0">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="HelpStateGroup">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0:0:0.5">
<VisualTransition.GeneratedEasingFunction>
<CircleEase EasingMode="EaseInOut"/>
</VisualTransition.GeneratedEasingFunction>
</VisualTransition>
</VisualStateGroup.Transitions>
<VisualState x:Name="HelpOpen">
<Storyboard>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="HelpGrid">
<EasingDoubleKeyFrame KeyTime="0" Value="0.95"/>
</DoubleAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)" Storyboard.TargetName="HelpGrid">
<DiscreteObjectKeyFrame KeyTime="0" Value="{x:Static Visibility.Visible}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="HelpClosed">
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border Background="#00427A" CornerRadius="3">
<DockPanel Margin="5">
<ContentPresenter DockPanel.Dock="Bottom" Margin="12,10,0,0" Content="{Binding Path=Detail}" Style="{StaticResource HelpText}"/>
<Label Style="{StaticResource HelpHeaderText}" Content="{Binding Path=Header}" DockPanel.Dock="Left" MaxHeight="50"/>
<Button x:Name="CloseHelpButton" Style="{StaticResource HelpButtonStyle}" Content="X" HorizontalAlignment="Right" VerticalAlignment="Top" DockPanel.Dock="Right" MaxHeight="50">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<ei:GoToStateAction x:Name="CloseAction" StateName="HelpClosed"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>
</DockPanel>
</Border>
</Grid>
但是,当我从父用户控件定位此控件并触发 HelpOpen 视觉状态时,我注意到帮助控件在动画完成后突然出现 - 它没有按预期淡入。
<view:HelpView x:Name="helpView" />
<Button x:Name="ButtonOpen" Margin="0,0,25,0" VerticalAlignment="Top" Content="Open">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<ei:GoToStateAction TargetObject="{Binding ElementName=helpView}" StateName="HelpOpen"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>
我相信这是因为帮助控件仅在动画结束时才可见,因此不呈现增加不透明度的过渡。
有没有办法指定在调整不透明度值之前将可见性属性设置为可见?