WPF:从代码中动画TranslateTransform

Question

我有一个WPF画布,我在其中动态地从代码创建对象.通过设置RenderTransform属性来转换这些对象,并且需要在其中一个转换中应用动画.目前,我无法将任何变换的属性设置为动画(虽然不会引发异常并且动画似乎运行 - 已完成的事件被引发).

此外,如果动画系统受到压力,有时则永远不会引发Storyboard.Completed事件.

我所有的例子都是来自XAML的转换动画.MSDN文档建议必须设置变换的x:Name属性才能使其可动画,但我还没有找到一种从代码中设置它的工作方式.

有任何想法吗？

这是重现问题的完整代码清单:

using System;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace AnimationCompletedTest {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window {

        Canvas panel;
        public MainWindow() {
            InitializeComponent();
            MouseDown += DoDynamicAnimation;

            Content = panel = new Canvas();
        }

        void DoDynamicAnimation(object sender, MouseButtonEventArgs args) {

            for (int i = 0; i < 12; ++i) {
                var e = new Ellipse {
                    Width = 16,
                    Height = 16,
                    Fill = SystemColors.HighlightBrush
                };
                Canvas.SetLeft(e, Mouse.GetPosition(this).X);
                Canvas.SetTop(e, Mouse.GetPosition(this).Y);

                var tg = new TransformGroup();
                var translation = new TranslateTransform(30, 0);
                tg.Children.Add(translation);
                tg.Children.Add(new RotateTransform(i * 30));
                e.RenderTransform = tg;

                panel.Children.Add(e);

                var s = new Storyboard();
                Storyboard.SetTarget(s, translation);
                Storyboard.SetTargetProperty(s, new PropertyPath(TranslateTransform.XProperty));

                s.Children.Add(
                    new DoubleAnimation(3, 100, new Duration(new TimeSpan(0, 0, 0, 1, 0))) {
                        EasingFunction = new PowerEase {EasingMode = EasingMode.EaseOut}
                    });

                s.Completed += 
                    (sndr, evtArgs) => {
                        Debug.WriteLine("Animation {0} completed {1}", s.GetHashCode(), Stopwatch.GetTimestamp());
                        panel.Children.Remove(e);
                    };

                Debug.WriteLine("Animation {0} started {1}", s.GetHashCode(), Stopwatch.GetTimestamp());

                s.Begin();
            }
        }

        [STAThread]
        public static void Main() {
            var app = new Application();
            app.Run(new MainWindow());
        }
    }
}

Answer 1

省略故事板:

var T = new TranslateTransform(40, 0);
Duration duration = new Duration(new TimeSpan(0, 0, 0, 1, 0));
DoubleAnimation anim = new DoubleAnimation(30, duration);
T.BeginAnimation(TranslateTransform.YProperty, anim);

(小修复语法)

Answer 2

似乎在谷歌搜索后我自己解决了这个问题.非常感谢MSDN文档以及Antares19在MSDN论坛中的帖子.

综上所述:

• 对于可由Storyboard定位的Freezable对象(如TranslateTransform),它必须具有注册名称.这可以通过调用FrameworkElement.RegisterName(..)来完成.

• 我将Storyboard对象添加到我注册TranslateTransform的同一Framework元素的ResourceDictionary.这可以通过调用ResourceDictionary.Add(..)来完成

这是更新的代码,现在可以很好地动画,并注册/注销添加的资源:

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace AnimationCompletedTest {

    public partial class MainWindow : Window {

        Canvas panel;
        public MainWindow() {
            InitializeComponent();
            MouseDown += DoDynamicAnimation;

            Content = panel = new Canvas();
        }

        void DoDynamicAnimation(object sender, MouseButtonEventArgs args) {
            for (int i = 0; i < 12; ++i) {
                var e = new Ellipse { Width = 16, Height = 16, Fill = SystemColors.HighlightBrush };
                Canvas.SetLeft(e, Mouse.GetPosition(this).X);
                Canvas.SetTop(e, Mouse.GetPosition(this).Y);

                var tg = new TransformGroup();
                var translation = new TranslateTransform(30, 0);
                var translationName = "myTranslation" + translation.GetHashCode();
                RegisterName(translationName, translation);
                tg.Children.Add(translation);
                tg.Children.Add(new RotateTransform(i * 30));
                e.RenderTransform = tg;

                panel.Children.Add(e);

                var anim = new DoubleAnimation(3, 100, new Duration(new TimeSpan(0, 0, 0, 1, 0))) {
                    EasingFunction = new PowerEase { EasingMode = EasingMode.EaseOut }
                };

                var s = new Storyboard();
                Storyboard.SetTargetName(s, translationName);
                Storyboard.SetTargetProperty(s, new PropertyPath(TranslateTransform.YProperty));
                var storyboardName = "s" + s.GetHashCode();
                Resources.Add(storyboardName, s);

                s.Children.Add(anim);

                s.Completed +=
                    (sndr, evtArgs) => {
                        panel.Children.Remove(e);
                        Resources.Remove(storyboardName);
                        UnregisterName(translationName);
                    };
                s.Begin();
            }
        }

        [STAThread]
        public static void Main() {
            var app = new Application();
            app.Run(new MainWindow());
        }
    }
}