Question

C＃：

public partial class MainWindow : Window
{
    Storyboard a = new Storyboard();
    int i;
    public MainWindow()
    {
        InitializeComponent();
        a.Completed += new EventHandler(a_Completed);
        a.Duration = TimeSpan.FromMilliseconds(10);
        a.Begin();
    }

    void a_Completed(object sender, EventArgs e)
    {
        textblock.Text = (++i).ToString();
        a.Begin();
    }
}

XAML：

<Window x:Class="Gui.MainWindow" x:Name="control"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="300" Width="300">
<Canvas>
    <TextBlock Name="textblock"></TextBlock>
</Canvas>

这段代码有什么问题？故事板在20-50轮之后停止。每次都有不同的数字

Answer 1

我相信这是因为你的代码在Storyboard的动画时钟和TextBlock的Text DependencyProperty之间没有创建任何关系。如果我不得不猜测我会说故事板何时出来，那么由于污染DependencyProperty（TextBlock.Text是一个DependencyProperty）更新管道，它在某个随机时间。创建如下所示的关联（RunTimeline或RunStoryboard将起作用，但显示查看此内容的替代方法）：

public partial class Window1 : Window
{
    Storyboard a = new Storyboard();
    StringAnimationUsingKeyFrames timeline = new StringAnimationUsingKeyFrames();
    DiscreteStringKeyFrame keyframe = new DiscreteStringKeyFrame();

    int i;

    public Window1()
    {
        InitializeComponent();

        //RunTimeline();
        RunStoryboard();
    }

    private void RunTimeline()
    {
        timeline.SetValue(Storyboard.TargetPropertyProperty, new PropertyPath("(TextBlock.Text)"));
        timeline.Completed += timeline_Completed;
        timeline.Duration = new Duration(TimeSpan.FromMilliseconds(10));
        textblock.BeginAnimation(TextBlock.TextProperty, timeline);
    }

    private void RunStoryboard()
    {
        timeline.SetValue(Storyboard.TargetPropertyProperty, new PropertyPath("(TextBlock.Text)"));
        a.Children.Add(timeline);
        a.Completed += a_Completed;
        a.Duration = new Duration(TimeSpan.FromMilliseconds(10));
        a.Begin(textblock);
    }

    void timeline_Completed(object sender, EventArgs e)
    {
        textblock.Text = (++i).ToString();
        textblock.BeginAnimation(TextBlock.TextProperty, timeline);
    }

    void a_Completed(object sender, EventArgs e)
    {
        textblock.Text = (++i).ToString();
        a.Begin(textblock);
    }
}

这对我来说只要我能让它运行（比以往任何时候都要长10倍）。

添

wpf故事板死亡

1 个答案: