在wpf项目中，我有这个XAML代码
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
xmlns:ic="clr-namespace:Microsoft.Expression.Interactivity.Core;assembly=Microsoft.Expression.Interactions"
x:Class="WpfApplication1.MainWindow"
xmlns:vsm="clr-namespace:System.Windows;assembly=WPFToolkit"
x:Name="Window"
Title="MainWindow"
Width="640" Height="480">
<vsm:VisualStateManager.VisualStateGroups>
<vsm:VisualStateGroup x:Name="VisualStateGroup">
<vsm:VisualState x:Name="Loading">
<Storyboard>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="control" Storyboard.TargetProperty="(UIElement.Visibility)">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="{x:Static Visibility.Visible}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="button" Storyboard.TargetProperty="(UIElement.Visibility)">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="{x:Static Visibility.Collapsed}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="button1" Storyboard.TargetProperty="(UIElement.Visibility)">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="{x:Static Visibility.Visible}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</vsm:VisualState>
<VisualState x:Name="Normal">
<Storyboard>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="control" Storyboard.TargetProperty="(UIElement.Visibility)">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="{x:Static Visibility.Collapsed}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</vsm:VisualStateGroup>
</vsm:VisualStateManager.VisualStateGroups>
<Grid x:Name="LayoutRoot">
<Grid.Resources>
<ControlTemplate x:Key="loadingAnimation">
<Image x:Name="content" Opacity="1">
<Image.Source>
<DrawingImage>
<DrawingImage.Drawing>
<DrawingGroup>
<GeometryDrawing Brush="Transparent">
<GeometryDrawing.Geometry>
<RectangleGeometry Rect="0,0,1,1"/>
</GeometryDrawing.Geometry>
</GeometryDrawing>
<DrawingGroup>
<DrawingGroup.Transform>
<RotateTransform x:Name="angle" Angle="0" CenterX="0.5" CenterY="0.5"/>
</DrawingGroup.Transform>
<GeometryDrawing Geometry="M0.9,0.5 A0.4,0.4,90,1,1,0.5,0.1">
<GeometryDrawing.Pen>
<Pen Brush="Green" Thickness="0.1"/>
</GeometryDrawing.Pen>
</GeometryDrawing>
<GeometryDrawing Brush="Green" Geometry="M0.5,0 L0.7,0.1 L0.5,0.2"/>
</DrawingGroup>
</DrawingGroup>
</DrawingImage.Drawing>
</DrawingImage>
</Image.Source>
</Image>
<ControlTemplate.Triggers>
<Trigger Property="Visibility" Value="Visible">
<Trigger.EnterActions>
<BeginStoryboard x:Name="animation">
<Storyboard>
<DoubleAnimation From="0" To="359" Duration="0:0:1.5" RepeatBehavior="Forever"
Storyboard.TargetName="angle" Storyboard.TargetProperty="Angle"/>
</Storyboard>
</BeginStoryboard>
</Trigger.EnterActions>
<Trigger.ExitActions>
<StopStoryboard BeginStoryboardName="animation"/>
</Trigger.ExitActions>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Grid.Resources>
<Grid.ColumnDefinitions>
<ColumnDefinition MinWidth="76.128" Width="Auto"/>
<ColumnDefinition MinWidth="547.872" Width="Auto"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="0.05*"/>
<RowDefinition Height="0.95*"/>
</Grid.RowDefinitions>
<Button x:Name="button" Margin="0,0,1,0.04" Width="100" Content="Load" d:LayoutOverrides="Height" Click="Button1_Click"/>
<Button x:Name="button1" HorizontalAlignment="Left" Margin="0,0,0,0.04" Width="100" Content="Stop" Grid.Column="1" d:LayoutOverrides="Height" Click="Button2_Click" Visibility="Collapsed"/>
<Control x:Name="control" Margin="10" Height="100" Grid.Row="1" Grid.ColumnSpan="2" Width="100" Template="{DynamicResource loadingAnimation}" Visibility="Collapsed"/>
</Grid>
</Window>
以及窗口后面的代码
public partial class MainWindow : Window
{
public MainWindow()
{
this.InitializeComponent();
}
private void Button1_Click(object sender, System.Windows.RoutedEventArgs e)
{
VisualStateManager.GoToState(this, "Loading", true);
}
private void Button2_Click(object sender, System.Windows.RoutedEventArgs e)
{
VisualStateManager.GoToState(this, "Normal", true);
}
}
但是，当我单击第一个按钮（button1）时，不会触发状态更改。 我做错了什么？
提前致谢
答案 0 :(得分：7)
根据MSDN，当您在控件模板之外使用Visual State Manager时，应使用GoToElementState方法，而不是GoToState方法。不过，我还没有测试过它。
答案 1 :(得分：5)
事实上，它是在.net 3.5上设计的。 This guy有一种解决方法。
答案 2 :(得分：0)
我尝试了你的代码并在设计器中遇到错误（VS2008 SP1）：
值不能为空。
参数名称：值
每当我编辑故事板代码时。重新加载xaml会暂时“修复”问题。代码仍然构建和运行，但我怀疑这个错误的原因可能会影响你的问题。
DiscreteObjectKeyFrame的定义对我来说有点偏僻。我在过去看过它的唯一方法就是this page所描述的，就像这样：
<vsm:VisualState x:Name="Focused">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="FocusVisualElement"
Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</vsm:VisualState>
但是，我尝试使用您的代码仍然无法使其工作，所以我即使这样 一个问题不是整个问题。
答案 3 :(得分：0)
创建一个附加属性以更改可视状态。这对你有用
public class StateManager : DependencyObject
{
public static string GetVisualStateProperty(DependencyObject obj)
{
return (string)obj.GetValue(VisualStatePropertyProperty);
}
public static void SetVisualStateProperty(DependencyObject obj, string value)
{
obj.SetValue(VisualStatePropertyProperty, value);
}
public static readonly DependencyProperty VisualStatePropertyProperty =
DependencyProperty.RegisterAttached(
"VisualStateProperty",
typeof(string),
typeof(StateManager),
new PropertyMetadata((s, e) =>
{
var propertyName = (string)e.NewValue;
var ctrl = s as Grid;
if (ctrl == null)
throw new InvalidOperationException("This attached property only supports types derived from FrameworkElement.");
var transitionWorked = System.Windows.VisualStateManager.GoToElementState(ctrl, (string)e.NewValue, true);
}));
}