使用 EventTrigger 设置属性 [英] Setting a property with an EventTrigger

问题描述

我希望能够使用 EventTrigger 设置属性，这有很多问题.

I want to be able to set a property with an EventTrigger, there's a number of problems with this.

1) EventTriggers 只支持 Actions，所以我必须使用 storyBoard 来设置我的属性.

1) EventTriggers only support Actions, so I must use a storyBoard to set my properties.

2) 一旦我使用故事板，我有两个选择:

2) Once I use a storyboard, I have two options:

• 停止:一旦动画停止，值将恢复到动画开始之前
• HoldEnd:这会锁定属性，因此无论是代码还是用户交互都无法更改动画所持有的属性.

在下面的示例中，我想在单击按钮时将 IsChecked 属性设置为 False，并且我希望用户能够更改 IsChecked 和/或我希望能够在代码中更改该属性.

In the below example, I want to set the IsChecked property to False when the button is clicked and I want the user to be able to change the IsChecked and/or I want to be able to change the property in code.

示例:

<EventTrigger
    SourceName="myButton"
    RoutedEvent="Button.Click">
    <EventTrigger.Actions>
        <BeginStoryboard>
            <Storyboard>
                <BooleanAnimationUsingKeyFrames
                    Storyboard.TargetName="myCheckBox"
                    Storyboard.TargetProperty="IsChecked"
                    FillBehavior="Stop">
                    <DiscreteBooleanKeyFrame
                        KeyTime="00:00:00"
                        Value="False" />
                </BooleanAnimationUsingKeyFrames>
            </Storyboard>
        </BeginStoryboard>
    </EventTrigger.Actions>
</EventTrigger>

我意识到我可以在故事板完成后使用Completed"事件将该值设置为 False.但是，在本例中，我希望将逻辑包含在 XAML 中，因为此逻辑将用于自定义控件并且仅特定于 UI.

I realize that I can use the "Completed" event after the storyboard completes to set the value to False. However, in this instance I want to contain the logic within the XAML, as this logic will be used on a custom control and is only specific to the UI.

推荐答案

尽管我喜欢 XAML，但对于此类任务，我转而使用代码隐藏.附加行为 是一个很好的模式.请记住，Expression Blend 3 提供了一种标准方式来编程和使用行为.Expression 社区网站上有一些现有的.

As much as I love XAML, for this kinds of tasks I switch to code behind. Attached behaviors are a good pattern for this. Keep in mind, Expression Blend 3 provides a standard way to program and use behaviors. There are a few existing ones on the Expression Community Site.

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