通过绑定通过滑块更改动画持续时间 [英] Change animation duration with slider by binding

问题描述

我正在情节提要中旋转带有以下代码的3D房子：

I am spinning a 3D house with the following code inside a storyboard:

<DoubleAnimation Storyboard.TargetName="HouseRotate" Storyboard.TargetProperty="Angle" From="0" To="-359" Duration="{Binding StringFormat=0:0:{0}, ElementName=slDuration, Path=Value, UpdateSourceTrigger=PropertyChanged}" RepeatBehavior="Forever"/>

我希望duration属性根据滑块值更改，但似乎停留在1第二。我知道滑块的值在正确更改，因为我已将其输出到标签。

I want the duration property to change based on the slider value, but it seems to be stuck at 1 second. I know the value of the slider is changing properly, because I have outputted it to a label.

推荐答案

在我看来，您需要一个适当的转换器，以便从 double 转换（ Slider 的属性值返回 double ）到持续时间结构。

In my opinion you need a proper converter in order to convert from double (Slider's property Value returns a double) to a Duration struct.

看看这个简单的例子：

<Window.Resources>
    <local:DoubleToDurationConverter x:Key="DoubleToDurationConverter" />
</Window.Resources>
<StackPanel>
    <Button Content="Click me for an animation" Margin="20" Padding="20">
        <Button.Triggers>
            <EventTrigger RoutedEvent="Button.Click">
                <BeginStoryboard>
                    <Storyboard>
                        <ColorAnimation To="Green"
                                Storyboard.TargetProperty="(Button.Background).(SolidColorBrush.Color)" 
                                FillBehavior="Stop" 
                                Duration="{Binding ElementName=slider, Path=Value, Mode=OneWay, Converter={StaticResource DoubleToDurationConverter}}" />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>
        </Button.Triggers>
    </Button>

    <Slider Name="slider" Minimum="10" Maximum="40" Value="30"
            Margin="5" AutoToolTipPlacement="TopLeft" IsSnapToTickEnabled="True" />
</StackPanel>

转换后的代码为：

public class DoubleToDurationConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        Duration duration = new Duration(TimeSpan.FromSeconds((double)value));
        return duration;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

请注意，无法更改动画运行时的持续时间。您可以在闲置时进行更改。

Keep in consideration that it is not possible to change the animation's duration while it is running. You can change it just when it is idle.

这篇关于通过绑定通过滑块更改动画持续时间的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！