对在运行时创建的CustomUserControl进行动画处理

Question

我遇到的问题是，开始故事板时，它会按预期更改对象中的值，但是没有可见的动画。情节提要板运行时没有任何反应，然后完成时，对象将立即获得情节提要板的最终结果（使用HoldEnd）。故事板的持续时间基本上就像一个延迟。

• 我正在将Scrollviewer与Stackpanel一起使用以显示动画的自定义用户控件。这些项目的高度为28像素，并且包含用于展开和折叠包含数据的节的按钮。
• [我在MainWindow中收到事件并使用Scrollviewer添加到scrData.Dispatcher.Invoke(()=>{})。

我怀疑问题可能是拥有这些控件的线程。由于它们是在Scrollviewer的调度程序方法中创建的，是否意味着UI线程拥有它们，或者触发事件的线程拥有它们？

我以前使用基本上相同的代码来制作动画，所以唯一的真正区别是这些控件是在运行时创建的。

任何帮助将不胜感激：）

这是我的代码的相关位：

MainWindow.cs：（接收数据，生成项目）：

    private void DataPoller_Update(object sender, DataPollerEventArgs e)
    {
        //New Data arrives here
        if (e.message == "results")
        {
            DisplayData(e.data);
        }
    }


    public void DisplayData(List<DataItem> data){
        scrData.Dispatcher.Invoke(() => {
            int i = 0;
            foreach (DataItem item in data) {
                if (IsInCurrentList(item.id)) {
                    Update_ExistingItemInfo(item);
                }
                else {
                    //Add new item to StackPanel
                    CustomControls.data_item newItem = new CustomControls.data_item(item);
                    stkData.Children.Insert(i, newItem);
                }
                i++;
            }
        }
    }

从UserControl的.cs：

    DataItem data;

    public data_item(DataItem newData)
    {
        InitializeComponent();
        data = newData;
        PopulateDataFields();
        //THESE ROWS SHOULD EXPAND OR COLLAPSE ON btnExpand_Click
        grdMain.RowDefinitions[1].Height = new GridLength(0);
        grdMain.RowDefinitions[2].Height = new GridLength(0);
    }
     private void btnExpand_Click(object sender, RoutedEventArgs e)
     {
         //For some reason, can't find reference to sb_Expand directly.
        btnExpand.Dispatcher.Invoke(()=> {
            if (rowDrilldown.ActualHeight > 0) {
                Storyboard sb = (Storyboard)this.Resources["sb_Collapse"];
                sb.Begin();
                }
            else {
                Storyboard sb = (Storyboard)this.Resources["sb_Expand"];
                sb.Begin();
                } 
        });
     }

从UserControl的xaml：

    <UserControl.Resources>
            <Storyboard x:Key="sb_Expand">
                <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(RowDefinition.Height)" Storyboard.TargetName="rowDrilldown" BeginTime="0" FillBehavior="HoldEnd">
                    <DiscreteObjectKeyFrame KeyTime="0:0:0">
                        <DiscreteObjectKeyFrame.Value>
                            <GridLength>0</GridLength>
                        </DiscreteObjectKeyFrame.Value>
                    </DiscreteObjectKeyFrame>
                    <DiscreteObjectKeyFrame KeyTime="0:0:0.25">
                        <DiscreteObjectKeyFrame.Value>
                            <GridLength>400</GridLength>
                        </DiscreteObjectKeyFrame.Value>
                    </DiscreteObjectKeyFrame>
                </ObjectAnimationUsingKeyFrames>
            </Storyboard>
            <Storyboard x:Key="sb_Collapse">
                <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(RowDefinition.Height)" Storyboard.TargetName="rowDrilldown" BeginTime="0" FillBehavior="HoldEnd">
                    <DiscreteObjectKeyFrame KeyTime="0:0:0">
                        <DiscreteObjectKeyFrame.Value>
                            <GridLength>400</GridLength>
                        </DiscreteObjectKeyFrame.Value>
                    </DiscreteObjectKeyFrame>
                    <DiscreteObjectKeyFrame KeyTime="0:0:0.25">
                        <DiscreteObjectKeyFrame.Value>
                            <GridLength>0</GridLength>
                        </DiscreteObjectKeyFrame.Value>
                    </DiscreteObjectKeyFrame>
                </ObjectAnimationUsingKeyFrames>
            </Storyboard>
        </UserControl.Resources>

        <Border BorderBrush="AliceBlue" BorderThickness="1" CornerRadius="4">
            <Grid x:Name="grdMain">
                <Grid.RowDefinitions>
                    <RowDefinition Height="28"/>
                    <RowDefinition Height="165"/>
                    <RowDefinition x:Name="rowDrilldown" Height="400"/>
                </Grid.RowDefinitions>
                <!--Textboxes and other CustomControls-->
            </Grid>
        </Border>

Answer 1

<Grid x:Name="grdMain">
            <VisualStateManager.VisualStateGroups>
                <VisualStateGroup x:Name="grdMain_VisualStateGroup">
                    <VisualState x:Name="ExpandIncident" Storyboard="{StaticResource sb_Expand}"/>
                    <VisualState x:Name="CollapseIncident" Storyboard="{StaticResource sb_Collapse}"/>
                </VisualStateGroup>
            </VisualStateManager.VisualStateGroups>

//在按钮上单击：bool tmp = ExtendedVisualStateManager.GoToElementState（this.grdMain as FrameworkElement，“ ExpandIncident”，true）;