c# - XAML : Setting the value of Storyboard animation from code behind

Question

我有一个要求，我需要一个按钮在几秒钟内从屏幕的一端移动到另一端(水平)。我试过这个并且在某种程度上有效。

<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.TranslateX)" Storyboard.TargetName="button">
            <EasingDoubleKeyFrame KeyTime="0:0:1" Value="0" />
            <!--<EasingDoubleKeyFrame KeyTime="0:0:6.9" Value="{Binding MainPage.width}">-->
                <EasingDoubleKeyFrame KeyTime="0:0:6.9" Value="-1283.725">
                <EasingDoubleKeyFrame.EasingFunction>
                    <CircleEase EasingMode="EaseIn"/>
                </EasingDoubleKeyFrame.EasingFunction>
            </EasingDoubleKeyFrame>
        </DoubleAnimationUsingKeyFrames>
        <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.TranslateY)" Storyboard.TargetName="button">
            <EasingDoubleKeyFrame KeyTime="0:0:1" Value="0"/>
            <!--<EasingDoubleKeyFrame KeyTime="0:0:6.9" Value="{Binding Path=MainPage.height}">-->
            <EasingDoubleKeyFrame KeyTime="0:0:6.9" Value="-467.732">
                <EasingDoubleKeyFrame.EasingFunction>
                    <CircleEase EasingMode="EaseIn"/>
                </EasingDoubleKeyFrame.EasingFunction>
            </EasingDoubleKeyFrame>
        </DoubleAnimationUsingKeyFrames>

但问题是由于屏幕尺寸和屏幕方向。 在大屏幕上它停在中间。我想动态设置EasingDoubleKeyFrame 的Value。代码隐藏或绑定(bind)或任何其他方式。

但我不想在代码隐藏中编写整个 Storyboard。

我可以使用

获取屏幕宽度和高度

Rect bounds = Window.Current.Bounds;
    static double height = 0;
    static double  width = 0;

    public MainPage()
    {
        this.InitializeComponent();
        this.Loaded += MainPage_Loaded;
        height = bounds.Height;
        width = -1 * bounds.Width;
    }

如果有简单的方法，请告诉我。

Answer 1

我找不到绑定(bind) Storyboard表达式的值的方法。

但是，变通方法是每次都手动设置它。我们可以通过给它一个名称属性来做到这一点:

    <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).    (CompositeTransform.TranslateX)" Storyboard.TargetName="button">
         <EasingDoubleKeyFrame KeyTime="0:0:1" Value="0" />
         <EasingDoubleKeyFrame x:Name="buttonTranslateX"  KeyTime="0:0:9.9" Value="0" />
     </DoubleAnimationUsingKeyFrames>

然后在页面初始化中像这样设置值:

Rect bounds = Window.Current.Bounds;
static double height = 0;
static double  width = 0;

public MainPage()
{
    this.InitializeComponent();
    this.Loaded += MainPage_Loaded;
    height = bounds.Height;
    width = -1 * bounds.Width;
    buttonTranslateX.Value = width;
}

这将创建一个漂亮的小动画，其中一个对象将在大约 9 秒内水平移动穿过屏幕。