在ItemsControl 中，添加头部下拉更新

 <ScrollViewer x:Name="viewer_hot">
                        <Grid Margin="0,-60,0,0">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="60"/>
                                <RowDefinition Height="Auto"/>
                            </Grid.RowDefinitions>
                            <Border CornerRadius="10">
                                <Border.Background>
                                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                        <GradientStop Color="White" Offset="0.217"/>
                                        <GradientStop Color="#FFC3FBEF" Offset="1"/>
                                    </LinearGradientBrush>
                                </Border.Background>
                                <Grid x:Name="grid">
                                    <TextBlock x:Name="txtRefresh" Text="下拉更新" Margin="219,8,133,0" Foreground="Black" FontSize="16" Height="22" VerticalAlignment="Top"/>
                                    <Image x:Name="image" Source="images/insect.png" Width="32" Height="32" HorizontalAlignment="Left" Margin="134,13,0,15" d:LayoutOverrides="Width" RenderTransformOrigin="0.5,0.5" >
                                        <Image.RenderTransform>
                                            <CompositeTransform/>
                                        </Image.RenderTransform>
                                    </Image>
                                    <TextBlock Height="22" Margin="194,0,194,4" TextWrapping="Wrap" Text="最近更新:" VerticalAlignment="Bottom" Foreground="Black" FontSize="14.667"/>
                                    <TextBlock HorizontalAlignment="Right" Height="22" Margin="0,0,133,4" TextWrapping="Wrap" Text="5分钟前" VerticalAlignment="Bottom" Width="57" Foreground="Black" FontSize="14.667"/>
                                </Grid>
                            </Border>
                            <ItemsControl  x:Name="listBox_Hot" Grid.Row="1"
                             Width="468" 
                             Margin="0,0,-12,-8"
                        ItemTemplate="{StaticResource ItemTemplate}" 
                             ItemsSource="{Binding Collection, Source={StaticResource SampleDataSource}}"
                             d:DataContext="{d:DesignData /SampleData/MainViewModelSampleData.xaml}">
                            </ItemsControl>
                        </Grid>
                    </ScrollViewer>

 

 

  //加载更新时播放的动画
            InsectTopSB.Completed += new EventHandler(InsectTopSB_Completed);
            InsectDownSB.Completed += new EventHandler(InsectDownSB_Completed);

 

 

codeBehind 页面：

  #region 下拉更新
        private double actuableOffset, validStartOffset;
        private bool mplStarted;
        bool IsStoBorOn = false; //当前更新动画是否在播放
        protected override void OnManipulationStarted(ManipulationStartedEventArgs e)
        {
            base.OnManipulationStarted(e);
            mplStarted = true;
        }
        protected override void OnManipulationCompleted(ManipulationCompletedEventArgs e)
        {
            //actuableOffset = 0;
            validStartOffset = 0;
            mplStarted = false;
            //pivot.Title = "actuableOffset" + actuableOffset;

            base.OnManipulationCompleted(e);
        }
        protected override void OnMouseMove(MouseEventArgs e)
        {
            if (pivot.SelectedIndex == 0)  //只有选中第一个时触发
            {
                //pivot.Title = "actuableOffset" + actuableOffset + "; VerticalOffset:" + viewer_hot.VerticalOffset;
                if (!IsStoBorOn && actuableOffset >= 100)  //&& viewer_hot.VerticalOffset == 0
                {
                    IsStoBorOn = true;
                    txtRefresh.Text = "正在更新...";
                    InsectTopSB.Begin();
                }

                if (!IsStoBorOn && actuableOffset < 100)
                {
                    IsTabStop = true;
                    txtRefresh.Text = "下拉更新";
                    InsectDownSB.Begin();
                }

                if (viewer_hot.VerticalOffset <= 20)
                {
                    if (mplStarted)
                    {
                        mplStarted = false;
                        validStartOffset = e.GetPosition(null).Y;
                    }
                    actuableOffset = e.GetPosition(null).Y - validStartOffset;
                }
            }
            base.OnMouseMove(e);
        }
        void InsectDownSB_Completed(object sender, EventArgs e)
        {
            IsStoBorOn = false;
        }

        void InsectTopSB_Completed(object sender, EventArgs e)
        {
            IsStoBorOn = false;
        }

        #endregion