Question

我找到了一些与WPF相关的示例，但没有找到Silverlight。

那么，在代码中设置Microsoft.Expression.Interactivity.Core.DataTrigger的工作示例是什么？

这是我目前拥有的代码，虽然它不起作用（没有例外，但在运行时没有任何反应）：

// Set up a storyboard
var duration = new Duration(TimeSpan.FromMilliseconds(400));
var animation = new ColorAnimation
{
    To = Colors.White,
    RepeatBehavior = RepeatBehavior.Forever,
    AutoReverse = true,
    Duration = duration
};
var sb = new Storyboard
{
    RepeatBehavior = RepeatBehavior.Forever, 
    AutoReverse = true, 
    Duration = duration
};
sb.Children.Add(animation);
Storyboard.SetTarget(animation, fillBrush);
Storyboard.SetTargetProperty(animation, new PropertyPath("(SolidColorBrush.Color)"));

// Configure the data trigger
var focusTrigger = new DataTrigger
{
    Binding = new Binding("IsFocussed")
    {
        Source = asset,
        Mode = BindingMode.OneWay
    }, 
    Value = true
};
focusTrigger.Actions.Add(new ControlStoryboardAction
{
    Storyboard = sb, 
    ControlStoryboardOption = ControlStoryboardOption.Play, 
    IsEnabled = true
});

asset.IsFocussed通过INotifyPropertyChanged更改并提出更改通知。

Answer 1

尝试使用命名空间：

System.Windows.Interactivity

并在“配置数据触发器”注释

后添加以下内容

// Configure the data trigger

// Configure the TriggerCollection
TriggerCollection triggers = Interaction.GetTriggers(fillBrush);
var focussedTrigger = new EventTrigger("GotFocus");
focussedTrigger.Actions.Add(
            new ControlStoryboardAction{Storyboard = sbFocussed});

var unfocussedTrigger = new EventTrigger("LostFocus");
unfocussedTrigger.Actions.Add(
            new ControlStoryboardAction { Storyboard = sbUnfocussed });

triggers.Add(focussedTrigger);
triggers.Add(unfocussedTrigger);

请注意：

using EventTrigger = System.Windows.Interactivity.EventTrigger;
using TriggerCollection = System.Windows.Interactivity.TriggerCollection;

Answer 2

最后我错过了两位：

将触发器添加到画笔：

var triggers = Interaction.GetTriggers(fillBrush);
triggers.Add(focusTrigger);

使用BindingOperators.SetBinding设置触发器的绑定，而不是Binding属性设置器：

var binding = new Binding("IsFocussed") { Source = asset, Mode = BindingMode.OneWay };
BindingOperations.SetBinding(focusTrigger, PropertyChangedTrigger.BindingProperty, binding);

我不明白为什么第二点是必要的，但似乎是。

希望能帮助其他人。

如何从Silverlight中的代码中使用DataTrigger？

2 个答案: