在按钮单击事件时，我在LongListSelector中显示项目周围的边框。但是，在离开页面然后返回时，我遇到了问题。离开时，我想以编程方式取消选择该项目（正在运行），但项目边框仍然显示在返回页面时。我怎么能删除边框？当用户希望在加载原始页面时没有选择任何项目时，这是非常令人困惑的，无论是从应用程序启动还是从导航到另一个页面。
MainPage.xaml中
<phone:PhoneApplicationPage.Resources>
<Style x:Key="PhoneButtonBase" TargetType="ButtonBase">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderBrush" Value="{StaticResource PhoneForegroundBrush}"/>
<Setter Property="Foreground" Value="{StaticResource PhoneForegroundBrush}"/>
<Setter Property="BorderThickness" Value="{StaticResource PhoneBorderThickness}"/>
<Setter Property="FontFamily" Value="{StaticResource PhoneFontFamilySemiBold}"/>
<Setter Property="FontSize" Value="{StaticResource PhoneFontSizeMedium}"/>
<Setter Property="Padding" Value="10,5,10,6"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ButtonBase">
<Grid Background="Transparent">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver"/>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentContainer">
<DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneButtonBasePressedForegroundBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ButtonBackground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneAccentBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentContainer">
<DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ButtonBackground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ButtonBackground">
<DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="ButtonBackground" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="0" Margin="{StaticResource PhoneTouchTargetOverhang}">
<ContentControl x:Name="ContentContainer" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Foreground="{TemplateBinding Foreground}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="PhoneRadioButtonCheckBoxBase" BasedOn="{StaticResource PhoneButtonBase}" TargetType="ToggleButton">
<Setter Property="Background" Value="{StaticResource PhoneRadioCheckBoxBrush}"/>
<Setter Property="BorderBrush" Value="{StaticResource PhoneRadioCheckBoxBorderBrush}"/>
<Setter Property="FontSize" Value="{StaticResource PhoneFontSizeMedium}"/>
<Setter Property="FontFamily" Value="{StaticResource PhoneFontFamilyNormal}"/>
<Setter Property="HorizontalContentAlignment" Value="Left"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="Padding" Value="0"/>
</Style>
<Style x:Key="RadioButtonStyle1" BasedOn="{StaticResource PhoneRadioButtonCheckBoxBase}" TargetType="RadioButton">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="RadioButton">
<Grid Background="Transparent">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver"/>
<VisualState x:Name="Pressed"/>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentContainer">
<DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="CheckStates">
<VisualState x:Name="Checked"/>
<VisualState x:Name="Unchecked"/>
<VisualState x:Name="Indeterminate"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<ContentControl x:Name="ContentContainer" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Foreground="{TemplateBinding Foreground}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</phone:PhoneApplicationPage.Resources>
...
<phone:LongListSelector x:Name="Recent" Margin="0,0,0,72"
LayoutMode="Grid" GridCellSize="108,108"
SelectionChanged="recent_SelectionChanged">
<phone:LongListSelector.ItemTemplate>
<DataTemplate>
<ContentControl HorizontalAlignment="Stretch" HorizontalContentAlignment="Left">
<ContentControl.Resources>
<Storyboard x:Name="CheckedStoryboard">
<ColorAnimation Duration="0" To="#FF1BA1E2" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="brd" d:IsOptimized="True"/>
</Storyboard>
</ContentControl.Resources>
<RadioButton x:Name="radioButton" HorizontalAlignment="Stretch" Margin="0,0,0,0" GroupName="A" Background="Black" Style="{StaticResource RadioButtonStyle1}" >
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<eim:ControlStoryboardAction Storyboard="{StaticResource CheckedStoryboard}"/>
</i:EventTrigger>
<i:EventTrigger EventName="Unchecked">
<eim:ControlStoryboardAction ControlStoryboardOption="Stop" Storyboard="{StaticResource CheckedStoryboard}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<Border x:Name="MyBorder" Background="Transparent">
<Border x:Name="brd" CornerRadius="10" Width="Auto" BorderThickness="3" BorderBrush="Transparent">
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu x:Name="imgListContextMenu" Background="{StaticResource PhoneChromeBrush}">
<toolkit:MenuItem Foreground="{StaticResource PhoneForegroundBrush}" Header="{Binding Path=LocalizedResources.MainPage_ContextMenu_Delete, Source={StaticResource LocalizedStrings}}" Click="deleteContextMenuItem_Click"/>
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
<Viewbox Width="108" Height="108">
<Image x:Name="recentImage" Source="{Binding Source}" Margin="0" Width="108"/>
</Viewbox>
</Border>
</Border>
</RadioButton>
</ContentControl>
</DataTemplate>
</phone:LongListSelector.ItemTemplate>
</phone:LongListSelector>
MainPage.xaml.cs中
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
base.OnNavigatedFrom(e);
//Removes the selected item, but the border still shows when returning to the page?
Recent.SelectedItem = null;
}
答案 0 :(得分：0)
您已经展示了很多代码，但大多数代码似乎与您的实际问题无关。您还没有说清楚如何突出显示所选项目。
根据您提供的有限信息，我猜您正在使用代码来触发更改项目的状态/样式。
然后，您正在更改列表中的SelectedItem属性，但您没有将其绑定到任何内容，因此它不会发生任何更改。
最简单的解决方案是绑定到所选项目，并在选择时具有不同的状态 或者，如果您真的想使用按钮按下来触发突出显示，则需要以类似的方式删除此突出显示。也就是说，在页面退出时，您可以清除突出显示的任何项目的突出显示。这可以通过遍历可视树来识别突出显示的项目，或者在您可以查询/更新的基础视图模型上具有[bound]属性来完成。