WPF中反转3D列表项

                                          WPF中反转3D列表项
                                                         周银辉

记得在苹果电脑中有一个很酷的3D旋转效果, 它可以将某项的正反面进行反转, 在WPF中可以很轻松地做到该效果.
点击这里查看
也可以粘贴此代码XamlPad中查看:

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:s="clr-namespace:System;assembly=mscorlib"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

  <Page.Resources>
    <x:Array Type="{x:Type s:String}" x:Key="src">
      <s:String>Foo</s:String>
      <s:String>Bar</s:String>
      <s:String>Spong</s:String>
      <s:String>One</s:String>
      <s:String>Two</s:String>
      <s:String>Three</s:String>
      <s:String>Four</s:String>
      <s:String>Five</s:String>
    </x:Array>


    <DataTemplate x:Key="frontTemplate">
      <GroupBox Header="Front" Background="White">
        <TextBlock FontSize="40" Foreground="Green" Text="{Binding}" />
      </GroupBox>
    </DataTemplate>
    <DataTemplate x:Key="backTemplate">
      <GroupBox Header="Back" Background="White">
        <StackPanel>
          <RadioButton Content="This" IsChecked="True" />
          <RadioButton Content="Is" />
          <RadioButton Content="The" />
          <RadioButton Content="Back" />
        </StackPanel>
      </GroupBox>
    </DataTemplate>

    <DataTemplate x:Key="flipItemTemplate">

      <!-- Note: Camera setup only works when this is square. -->
      <Grid Width="200" Height="200">

        <!-- Provides 3D rotation transition. Hidden except for when animation is
       active. -->
        <Viewport3D Grid.Column="0" x:Name="vp3D" Visibility="Hidden">
          <Viewport3D.Camera>
            <PerspectiveCamera x:Name="camera" Position="0,0,0.5" LookDirection="0,0,-1" FieldOfView="90" />
          </Viewport3D.Camera>

          <Viewport3D.Children>

            <ModelVisual3D>
              <ModelVisual3D.Content>
                <Model3DGroup>
                  <DirectionalLight Color="#444" Direction="0,0,-1" />
                  <AmbientLight Color="#BBB" />
                </Model3DGroup>
              </ModelVisual3D.Content>
            </ModelVisual3D>
            <ModelVisual3D>
              <ModelVisual3D.Content>
                <GeometryModel3D>


                  <!-- Simple flat, square surface -->
                  <GeometryModel3D.Geometry>
                    <MeshGeometry3D
                     TriangleIndices="0,1,2 2,3,0"
                     TextureCoordinates="0,1 1,1 1,0 0,0"
                     Positions="-0.5,-0.5,0 0.5,-0.5,0 0.5,0.5,0 -0.5,0.5,0" />
                  </GeometryModel3D.Geometry>


                  <!-- Front of shape shows the content of 'frontHost' -->
                  <GeometryModel3D.Material>
                    <DiffuseMaterial>
                      <DiffuseMaterial.Brush>
                        <VisualBrush Visual="{Binding ElementName=frontHost}" />
                      </DiffuseMaterial.Brush>
                    </DiffuseMaterial>
                  </GeometryModel3D.Material>


                  <!-- Back of shape shows the content of 'backHost' -->
                  <GeometryModel3D.BackMaterial>
                    <DiffuseMaterial>
                      <DiffuseMaterial.Brush>
                        <VisualBrush Visual="{Binding ElementName=backHost}">
                          <VisualBrush.RelativeTransform>
                            <!-- By default, this would come out backwards because we're on the
                                   back on the shape. Flip it to make it right. -->
                            <ScaleTransform ScaleX="-1" CenterX="0.5" />
                          </VisualBrush.RelativeTransform>
                        </VisualBrush>
                      </DiffuseMaterial.Brush>
                    </DiffuseMaterial>
                  </GeometryModel3D.BackMaterial>

                  <!-- Rotation transform used for transition. -->
                  <GeometryModel3D.Transform>
                    <RotateTransform3D>
                      <RotateTransform3D.Rotation>
                        <AxisAngleRotation3D x:Name="rotate" Axis="0,3,0" Angle="0" />
                      </RotateTransform3D.Rotation>
                    </RotateTransform3D>
                  </GeometryModel3D.Transform>
                </GeometryModel3D>
              </ModelVisual3D.Content>
            </ModelVisual3D>
          </Viewport3D.Children>

        </Viewport3D>

        <!-- We use a pair of nested Borders to wrap the content that's going to go on
       each side of the rotating model.
       The reason is that we need to be able to fade these real bits of UI in and out
       as we transition from front to back, but we need to make sure the VisualBrush
       in the 3D model doesn't also get faded out. So the VisualBrush uses the inner
       Border, while the fade is applied to the outer one.
  -->
        <Border x:Name="frontWrapper">
          <!-- Note, it's important that this element has visuals that completely fill the space, as
       otherwise it messes with the VisualBrush's size in the 3D model. Setting the background
       has that effect, even a transparent one. -->
          <Border x:Name="frontHost" Background="Transparent">
            <Border.Triggers>
              <EventTrigger RoutedEvent="Grid.MouseDown">
                <BeginStoryboard>
                  <Storyboard>
                    <!-- Make the Viewport3D visible only for the duration of the rotation. -->
                    <ObjectAnimationUsingKeyFrames
                           Storyboard.TargetName="vp3D"
                           Storyboard.TargetProperty="Visibility">
                      <DiscreteObjectKeyFrame KeyTime="0:0:0" Value="{x:Static Visibility.Visible}" />
                      <DiscreteObjectKeyFrame KeyTime="0:0:1.1" Value="{x:Static Visibility.Hidden}" />
                    </ObjectAnimationUsingKeyFrames>

                    <!-- Make the background element visible. (It won't actually appear until it is
                 faded in right at the end of the animation.) -->
                    <ObjectAnimationUsingKeyFrames
                           Storyboard.TargetName="backWrapper"
                           Storyboard.TargetProperty="Visibility">
                      <DiscreteObjectKeyFrame KeyTime="0:0:1" Value="{x:Static Visibility.Visible}"/>
                    </ObjectAnimationUsingKeyFrames>


                    <!-- Hide the foreground element. It will already be invisible by this time
                 because we fade it out right at the start of the animation. However, until
                 we set its Visibility to Hidden, it will still be visible to the mouse -->
                    <ObjectAnimationUsingKeyFrames
                           Storyboard.TargetName="frontWrapper"
                           Storyboard.TargetProperty="Visibility">
                      <DiscreteObjectKeyFrame KeyTime="0:0:0.05" Value="{x:Static Visibility.Hidden}" />
                    </ObjectAnimationUsingKeyFrames>


                    <!-- Fade the front wrapper out. The Viewport3D is behind us, so it'll fade into
                 view at this point. The reason for fading is to avoid a visible step as we
                 switch from the real UI to the copy projected onto the 3D model. -->
                    <DoubleAnimation To="0" Duration="0:0:0.05"
                           Storyboard.TargetName="frontWrapper"
                           Storyboard.TargetProperty="Opacity" />

                    <!-- Fade the back wrapper in. Once the spin completes, we fade the real back UI
                 in over the Viewport3D - using a fade to avoid a sudden jolt between the
                 slightly fuzzy 3D look and the real UI. -->
                    <DoubleAnimation BeginTime="0:0:1.05" Duration="0:0:0.05" To="1"
                           Storyboard.TargetName="backWrapper"
                           Storyboard.TargetProperty="Opacity" />

                    <!-- 3D animation. Move the camera out slightly as we spin, so the model fits entirely
                 within the field of view. Rotate the model 180 degrees. -->
                    <Point3DAnimation To="0,0,1.1" From="0,0,0.5"
                           BeginTime="0:0:0.05" Duration="0:0:0.5" AutoReverse="True" DecelerationRatio="0.3"
                           Storyboard.TargetName="camera"
                           Storyboard.TargetProperty="(PerspectiveCamera.Position)" />
                    <DoubleAnimation From="0" To="180" AccelerationRatio="0.3" DecelerationRatio="0.3"
                           BeginTime="0:0:0.05" Duration="0:0:1"
                           Storyboard.TargetName="rotate"
                           Storyboard.TargetProperty="Angle" />
                  </Storyboard>
                </BeginStoryboard>
              </EventTrigger>
            </Border.Triggers>
            <ContentPresenter  Content="{Binding}" ContentTemplate="{StaticResource frontTemplate}" />
          </Border>
        </Border>
        <Border x:Name="backWrapper" Grid.Column="0"  Visibility="Hidden" Opacity="0">
          <Border x:Name="backHost" Background="Transparent">
            <Border.Triggers>
              <EventTrigger RoutedEvent="Grid.MouseDown">
                <BeginStoryboard>
                  <Storyboard>
                    <ObjectAnimationUsingKeyFrames
                           Storyboard.TargetName="vp3D"
                           Storyboard.TargetProperty="Visibility">
                      <DiscreteObjectKeyFrame KeyTime="0:0:0" Value="{x:Static Visibility.Visible}" />
                      <DiscreteObjectKeyFrame KeyTime="0:0:1.1" Value="{x:Static Visibility.Hidden}" />
                    </ObjectAnimationUsingKeyFrames>

                    <ObjectAnimationUsingKeyFrames
                           Storyboard.TargetName="frontWrapper"
                           Storyboard.TargetProperty="Visibility">
                      <DiscreteObjectKeyFrame KeyTime="0:0:1" Value="{x:Static Visibility.Visible}"/>
                    </ObjectAnimationUsingKeyFrames>
                    <ObjectAnimationUsingKeyFrames
                           Storyboard.TargetName="backWrapper"
                           Storyboard.TargetProperty="Visibility">
                      <DiscreteObjectKeyFrame KeyTime="0:0:0.05" Value="{x:Static Visibility.Hidden}" />
                    </ObjectAnimationUsingKeyFrames>

                    <DoubleAnimation To="0" Duration="0:0:0.05"
                           Storyboard.TargetName="backWrapper"
                           Storyboard.TargetProperty="Opacity" />
                    <DoubleAnimation BeginTime="0:0:1.05" Duration="0:0:0.05"
                           Storyboard.TargetName="frontWrapper"
                           Storyboard.TargetProperty="Opacity" />

                    <Point3DAnimation To="0,0,1.1" From="0,0,0.5"
                           BeginTime="0:0:0.05" Duration="0:0:0.5" AutoReverse="True" DecelerationRatio="0.3"
                           Storyboard.TargetName="camera"
                           Storyboard.TargetProperty="(PerspectiveCamera.Position)" />
                    <DoubleAnimation From="180" To="360" AccelerationRatio="0.3" DecelerationRatio="0.3"
                           BeginTime="0:0:0.05" Duration="0:0:1"
                           Storyboard.TargetName="rotate"
                           Storyboard.TargetProperty="Angle" />
                  </Storyboard>
                </BeginStoryboard>
              </EventTrigger>
            </Border.Triggers>
            <ContentPresenter Content="{Binding}" ContentTemplate="{StaticResource backTemplate}" />
          </Border>
        </Border>


      </Grid>
    </DataTemplate>

  </Page.Resources>

  <ScrollViewer>
    <ItemsControl ItemsSource="{StaticResource src}" ItemTemplate="{StaticResource flipItemTemplate}">
      <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
          <WrapPanel />
        </ItemsPanelTemplate>
      </ItemsControl.ItemsPanel>

    </ItemsControl>
  </ScrollViewer>


</Page>

更多请参考这里: http://www.interact-sw.co.uk/iangblog/2007/05/17/wpf-flippable-3D-list