C# 如何在代码中向自定义控件模板动态添加新的可视状态？

是否可以在代码中以编程方式将新的

VisualState

添加到CustomControl模板的

VisualStateManager

例如，我可以在设计时手动将此XAML添加到CustomControl模板：

<VisualState x:Name="First">
   <Storyboard>
      <ColorAnimation Duration="0:0:0"
                      Storyboard.TargetName="SBorder"
                      Storyboard.TargetProperty="(Background).(SolidColorBrush.Color)" To="Red" />
    </Storyboard>
</VisualState>

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

---

但是如何在运行时添加新的

VisualState

？

我认为这是可行的，但绝非易事

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

这应该起作用：

Grid grid = this.Template.FindName("RootElement", this) as Grid;
(VisualStateManager.GetVisualStateGroups(grid)).Add(new VisualStateGroup() { /* the code for your visualstategroup here */ });

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

（您需要根据模板根元素名称的类型以及设置visualstatemanager的位置进行调整，但所有这些都可以工作

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

此外，这还添加了一个新的visualStateGroup，而不仅仅是visualState。如果要将visualState添加到现有visualStateGroup，则必须首先从集合中获取该组，但这是常见的“从集合中获取元素”内容

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

基本上：

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

获取包含visualStateManager的模板元素

使用

VisualStateManager.GetVisualStateGroups（）静态方法获取当前visualStateGroups

从集合中获取所需的组，或创建一个新组并将其添加到集合中

在此组中添加新的visualState

---

希望这有帮助。

我建议您使用XAML创建组本身

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

您必须找到您要查找的VisualState组，如下所示：

VisualStateGroup visualStateGroupLookingFor = null;
var visualStateGroups = (VisualStateManager.GetVisualStateGroups(LayoutRoot));
foreach (VisualStateGroup state in visualStateGroups) {
    if (state.Name == "VisualStateGroupMine") {
        visualStateGroupLookingFor = state;
        break;
        }
    }

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

然后，您必须创建一个新的VisualState和故事板来添加，例如：

var visualState = new VisualState();
var storyBoard = new Storyboard();

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

现在，创建动画：

var animation = new DoubleAnimation();
animation.To = 10.0;

//assuming this is instance of class ClassFoo
//and you want to animate it's Width
Storyboard.SetTarget(animation, this);
Storyboard.SetTargetProperty(animation, new PropertyPath(ClassFoo.WidthProperty));

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

并设置动画的目标：

var animation = new DoubleAnimation();
animation.To = 10.0;

//assuming this is instance of class ClassFoo
//and you want to animate it's Width
Storyboard.SetTarget(animation, this);
Storyboard.SetTargetProperty(animation, new PropertyPath(ClassFoo.WidthProperty));

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

最后，将动画添加到情节提要，为其命名，并将其添加到VisualState组：

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

就这样，像往常一样用

storyBoard.Children.Add(animation);
visualState.Storyboard = storyBoard;
visualState.Name = "CoolNameLikeWidthAnimation";
visualStateGroupLookingFor.States.Add(visualState);

VisualStateManager.GoToState(this, "CoolNameLikeWidthAnimation", true);