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Wpf 使用WrapPanel和ScrollViewer在列表框中包装图像,选定的项目将消失!_Wpf_Silverlight_Listbox_Scrollviewer_Wrappanel - Fatal编程技术网

Wpf 使用WrapPanel和ScrollViewer在列表框中包装图像,选定的项目将消失!

Wpf 使用WrapPanel和ScrollViewer在列表框中包装图像,选定的项目将消失!,wpf,silverlight,listbox,scrollviewer,wrappanel,Wpf,Silverlight,Listbox,Scrollviewer,Wrappanel,我使用列表框来显示800个缩略图的水平显示,但一次只能显示6个(取决于屏幕分辨率),我希望使用列表两侧的按钮浏览图像 我目前正在工作,但当我将列表框的SelectedItem更改为下一个/上一个缩略图时,ScrollViewer不会自动将SelectedItem保留在视图中。6个缩略图之后的SelectedItem将立即消失 我可以移动滚动条来查看SelectedItem,但这还不够好,在最终版本中,我甚至不想要滚动条,我只希望用户能够按住左键或右键,然后快速浏览照片 另外,为了告诉你我为什么要

我使用列表框来显示800个缩略图的水平显示,但一次只能显示6个(取决于屏幕分辨率),我希望使用列表两侧的按钮浏览图像

我目前正在工作,但当我将列表框的SelectedItem更改为下一个/上一个缩略图时,ScrollViewer不会自动将SelectedItem保留在视图中。6个缩略图之后的SelectedItem将立即消失

我可以移动滚动条来查看SelectedItem,但这还不够好,在最终版本中,我甚至不想要滚动条,我只希望用户能够按住左键或右键,然后快速浏览照片

另外,为了告诉你我为什么要这样做,每次在列表框中更改SelectedItem时,它都会更改上面照片的全尺寸预览

Silverlight 2中是否有确保ScrollViewer(在列表框中)中的SelectedItem保留在可查看区域中的方法

以下是列表框的当前XAML:

    <ListBox x:Name="lbPhotos" 
         ItemsSource="{Binding Photos}" 
         SelectedItem="{Binding Path=SelectedPhoto, Mode=TwoWay}" 
         ItemContainerStyle="{StaticResource ReflectionListBoxItemStyle}">

    <ListBox.ItemsPanel>
        <ItemsPanelTemplate>
            <controls:WrapPanel Margin="0" />
        </ItemsPanelTemplate>
    </ListBox.ItemsPanel>

    <ListBox.Template>
        <ControlTemplate>
            <Grid>
                <ScrollViewer VerticalScrollBarVisibility="Hidden" HorizontalScrollBarVisibility="Hidden" 
                              BorderThickness="0" MaxHeight="170">
                    <ItemsPresenter />
                </ScrollViewer>
            </Grid>
        </ControlTemplate>
    </ListBox.Template>

    <ListBox.ItemTemplate>
        <DataTemplate>
            <Image MaxHeight="85" Source="{Binding ThumbnailUrl, Converter={StaticResource UrlToBitmapImageConverter}}" />
        </DataTemplate>
    </ListBox.ItemTemplate>

  </ListBox>

项目容器样式如下所示:

<Style x:Key="ReflectionListBoxItemStyle" TargetType="ListBoxItem">
        <Setter Property="Padding" Value="3"/>
        <Setter Property="HorizontalContentAlignment" Value="Left"/>
        <Setter Property="VerticalContentAlignment" Value="Top"/>
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="TabNavigation" Value="Local"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ListBoxItem">
                    <Grid Background="{TemplateBinding Background}">
                        <vsm:VisualStateManager.VisualStateGroups>
                            <vsm:VisualStateGroup x:Name="CommonStates">
                                <vsm:VisualState x:Name="Normal"/>
                                <vsm:VisualState x:Name="MouseOver">
                                    <Storyboard>
                                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MainContentBorder" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)">
                                            <SplineColorKeyFrame KeyTime="00:00:00" Value="{StaticResource PinkColor}"/>
                                        </ColorAnimationUsingKeyFrames>
                                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="ReflectionBorder" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)">
                                            <SplineColorKeyFrame KeyTime="00:00:00" Value="{StaticResource PinkColor}"/>
                                        </ColorAnimationUsingKeyFrames>
                                    </Storyboard>
                                </vsm:VisualState>
                                <vsm:VisualState x:Name="Disabled">
                                </vsm:VisualState>
                            </vsm:VisualStateGroup>
                            <vsm:VisualStateGroup x:Name="SelectionStates">
                                <vsm:VisualState x:Name="Unselected"/>
                                <vsm:VisualState x:Name="Selected">
                                    <Storyboard>
                                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MainContentBorder" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)">
                                            <SplineColorKeyFrame KeyTime="00:00:00" Value="{StaticResource PinkColor}"/>
                                        </ColorAnimationUsingKeyFrames>
                                        <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="ReflectionBorder" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)">
                                            <SplineColorKeyFrame KeyTime="00:00:00" Value="{StaticResource PinkColor}"/>
                                        </ColorAnimationUsingKeyFrames>
                                    </Storyboard>
                                </vsm:VisualState>
                            </vsm:VisualStateGroup>
                            <vsm:VisualStateGroup x:Name="FocusStates">
                                <vsm:VisualState x:Name="Focused">
                                </vsm:VisualState>
                                <vsm:VisualState x:Name="Unfocused"/>
                            </vsm:VisualStateGroup>
                        </vsm:VisualStateManager.VisualStateGroups>
                        <StackPanel Orientation="Vertical" Margin="0,0,4,0">
                        <!-- Image -->
                                <Border HorizontalAlignment="{TemplateBinding HorizontalAlignment}" BorderThickness="3,3,3,2" CornerRadius="1" x:Name="MainContentBorder" VerticalAlignment="{TemplateBinding VerticalAlignment}">
                                    <Border.BorderBrush>
                                        <SolidColorBrush Color="#00000000"/>
                                    </Border.BorderBrush>
                                    <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}"/>
                                </Border>

                                <!-- Image reflection -->
                                <Border RenderTransformOrigin="0.5,0.5" BorderThickness="3,2,3,3" CornerRadius="1" VerticalAlignment="{TemplateBinding VerticalAlignment}" Margin="0,2,0,0" x:Name="ReflectionBorder" HorizontalAlignment="{TemplateBinding HorizontalAlignment}">
                                    <Border.BorderBrush>
                                        <SolidColorBrush Color="#00000000"/>
                                    </Border.BorderBrush>
                                    <Border.OpacityMask>
                                        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                            <GradientStop Color="#66000000" Offset="1"/>
                                            <GradientStop Color="#00000000" Offset="0.348"/>
                                        </LinearGradientBrush>
                                    </Border.OpacityMask>
                                    <Border.RenderTransform>
                                        <TransformGroup>
                                            <ScaleTransform ScaleY="-1"/>
                                        </TransformGroup>
                                    </Border.RenderTransform>
                                    <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}"/>
                            </Border>
                            </StackPanel>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

您可以使用ScrollIntoView方法传入所选项目


我最终使用了ScrollViewer.ScrollToHorizontalOffset,因为ScrollIntoView不工作

我遇到了这个问题,你是如何计算水平偏移的?仅仅通过获取索引并将缩略图的宽度加在一起?我也尝试过这一方法,但它不适用于自定义内容,除非您将scrollviewer控件命名为与MS listbox模板中的命名完全相同的名称,请参见错误报告