如何对新添加的项目进行动画处理以在 wpf 的列表视图中列出

Question

我正在创建一个动态列表视图lstDummies，其中包含一个虚拟 UserController dummyItem：

dummyItem item;

for (int i = 0; i < 100; i++)

{

    item = new dummyItem ();

    lstDummies.Items.Add(item);

}

这是虚拟项目 XAML ：

<UserControl x:Class="Kiosk.control.dummyItem"

         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 

         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 

         mc:Ignorable="d" 

         d:DesignHeight="300" d:DesignWidth="300"

         x:Name="dummyItem">

<Grid Background="BurlyWood">

    <TextBox Text="hello world!" HorizontalAlignment="Center" VerticalAlignment="Center"></TextBox>

</Grid>

</UserControl>

这是我的 XAML：

 <ListView Grid.Row="1" x:Name="lstDummies">

        <ListView.Resources>

            <Style TargetType="{x:Type ListViewItem}">

                <Style.Triggers>

                    <EventTrigger RoutedEvent="Loaded">

                        <EventTrigger.Actions>

                            <BeginStoryboard>

                                <Storyboard>

                                    <DoubleAnimation Storyboard.TargetProperty="Opacity" From="0" To="1" Duration="0:0:0.5">

                                    </DoubleAnimation>

                                </Storyboard>

                            </BeginStoryboard>

                        </EventTrigger.Actions>

                    </EventTrigger>

                </Style.Triggers>

            </Style>

        </ListView.Resources>

        <ListView.ItemsPanel >

            <ItemsPanelTemplate >

                <UniformGrid VerticalAlignment="Top" HorizontalAlignment="Left" Columns="17"/>

            </ItemsPanelTemplate>

        </ListView.ItemsPanel>

 </ListView>

现在，当新项目添加到 lstDummies 时，我想要淡入淡出效果。

Answer 1

这对我来说效果很好，即Opacity设置为0然后在ListViewItem加载后进行动画处理：<ListView x:Name="lstDummies">&nbsp; &nbsp; <ListView.Resources>&nbsp; &nbsp; &nbsp; &nbsp; <Style TargetType="{x:Type ListViewItem}">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Setter Property="Opacity" Value="0" />&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <EventTrigger RoutedEvent="Loaded">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <EventTrigger.Actions>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <BeginStoryboard>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Storyboard>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <DoubleAnimation Storyboard.TargetProperty="Opacity" From="0" To="1" Duration="0:0:2">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </DoubleAnimation>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Storyboard>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </BeginStoryboard>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </EventTrigger.Actions>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </EventTrigger>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; </Style>&nbsp; &nbsp; </ListView.Resources>&nbsp; &nbsp; <ListView.ItemsPanel >&nbsp; &nbsp; &nbsp; &nbsp; <ItemsPanelTemplate >&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <UniformGrid VerticalAlignment="Top" HorizontalAlignment="Left" Columns="17"/>&nbsp; &nbsp; &nbsp; &nbsp; </ItemsPanelTemplate>&nbsp; &nbsp; </ListView.ItemsPanel>&nbsp; &nbsp; <ListView.ItemTemplate>&nbsp; &nbsp; &nbsp; &nbsp; <DataTemplate>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Rectangle Width="50" Height="50" Fill="Green" />&nbsp; &nbsp; &nbsp; &nbsp; </DataTemplate>&nbsp; &nbsp; </ListView.ItemTemplate></ListView>如果您希望项目一项一项地淡入，您应该在调用之间引入延迟Add：private async void Button_Click(object sender, RoutedEventArgs e){&nbsp; &nbsp; for (int i = 0; i < 100; i++)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; lstDummies.Items.Add(new dummyItem());&nbsp; &nbsp; &nbsp; &nbsp; await Task.Delay(100);&nbsp; &nbsp; }}