C# 如何以编程方式取消选择LongListSelector项
我希望以编程方式取消选择LongListSelector中的项目，但我不确定如何完成此任务。我使用SelectionChanged事件处理程序使选择正确工作。我的问题出现在离开页面然后返回时，我正在清除SelectionChanged事件中使用的值，因为它们可能会更改，但如果需要在LongListSelector中重新选择该项，则该事件不会触发，因为它认为该项已被选中 MainPage.xamlC# 如何以编程方式取消选择LongListSelector项,c#,xaml,windows-phone-7,windows-phone-8,longlistselector,C#,Xaml,Windows Phone 7,Windows Phone 8,Longlistselector,我希望以编程方式取消选择LongListSelector中的项目，但我不确定如何完成此任务。我使用SelectionChanged事件处理程序使选择正确工作。我的问题出现在离开页面然后返回时，我正在清除SelectionChanged事件中使用的值，因为它们可能会更改，但如果需要在LongListSelector中重新选择该项，则该事件不会触发，因为它认为该项已被选中 MainPage.xaml <phone:PhoneApplicationPage.Resources>
<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="6,6" Width="108"/>
</Viewbox>
</Border>
</Border>
</RadioButton>
</ContentControl>
</DataTemplate>
</phone:LongListSelector.ItemTemplate>
</phone:LongListSelector>
要清除选择，只需将
SelectedItemRecent.SelectedItem = null;
谢谢，这实际上清除了当前选定的项目，尽管边框仍然存在？我怎样才能禁用边界呢？我还没有在我的开发机器上检查（现在不在手边），但我总是使用.SelectedIndex=-1Hm，我真的很想看看这是否也会删除边界。我唯一能想到的另一个选择是在代码隐藏中控制情节提要，我没有这方面的经验。你能帮我一下吗
Recent.SelectedItem = null;