wpf 在以编程方式添加的控件上使用 Storyboard 动画

Using a Storyboard animation on a programmatically-added control

提问by Eric Smith

I'm trying to fade in a new control to my application's "app" area which is programmatically added after the existing controls are removed. My code looks like this:

我正在尝试将新控件淡入到我的应用程序的“应用程序”区域，该区域是在删除现有控件后以编程方式添加的。我的代码如下所示：

        void settingsButton_Clicked(object sender, EventArgs e)
    {
        ContentCanvas.Children.Clear();

        // Fade in settings panel
        NameScope.SetNameScope(this, new NameScope());

        SettingsPane s = new SettingsPane();
        s.Name = "settingsPane";

        this.RegisterName(s.Name, s);
        this.Resources.Add(s.Name, s);

        Storyboard sb = new Storyboard();

        DoubleAnimation settingsFade = new DoubleAnimation();
        settingsFade.From = 0;
        settingsFade.To = 1;
        settingsFade.Duration = new Duration(TimeSpan.FromSeconds(0.33));
        settingsFade.RepeatBehavior = new RepeatBehavior(1);
        Storyboard.SetTargetName(settingsFade, s.Name);
        Storyboard.SetTargetProperty(settingsFade, new PropertyPath(UserControl.OpacityProperty));

        ContentCanvas.Children.Add(s);

        sb.Children.Add(settingsFade);
        sb.Begin();
    }

However, when I run this code, I get the error "No applicable name scope exists to resolve the name 'settingsPane'."

但是，当我运行此代码时，出现错误“不存在适用的名称范围来解析名称‘settingsPane’。”

What am I possibly doing wrong? I'm pretty sure I've registered everything properly :(

我可能做错了什么？我很确定我已经正确注册了所有内容:(

回答by

I wouldn't hassle with the NameScopes etc. and would rather use Storyboard.SetTarget instead.

我不会为 NameScopes 等烦恼，而是更愿意使用 Storyboard.SetTarget。

var b = new Button() { Content = "abcd" };
stack.Children.Add(b);

var fade = new DoubleAnimation()
{
    From = 0,
    To = 1,
    Duration = TimeSpan.FromSeconds(5),
};

Storyboard.SetTarget(fade, b);
Storyboard.SetTargetProperty(fade, new PropertyPath(Button.OpacityProperty));

var sb = new Storyboard();
sb.Children.Add(fade);

sb.Begin();

回答by Carlos Angulo

I solved the problem using this as parameter in the begin method, try:

我在 begin 方法中使用 this 作为参数解决了这个问题，尝试：

sb.Begin(this);

Because the name is registered in the window.

因为名字是在窗口中注册的。

回答by Cheeso

I agree, the namescopes are probably the wrong thing to use for this scenario. Much simpler and easier to use SetTarget rather than SetTargetName.

我同意，在这种情况下使用名称范围可能是错误的。使用 SetTarget 比使用 SetTargetName 要简单得多。

In case it helps anyone else, here's what I used to highlight a particular cell in a table with a highlight that decays to nothing. It's a little like the StackOverflow highlight when you add a new answer.

以防它对其他人有帮助，这是我用来突出显示表格中特定单元格的方法，突出显示衰减为零。这有点像添加新答案时的 StackOverflow 突出显示。

    TableCell cell = table.RowGroups[0].Rows[row].Cells[col];

    // The cell contains just one paragraph; it is the first block
    Paragraph p = (Paragraph)cell.Blocks.FirstBlock;

    // Animate the paragraph: fade the background from Yellow to White,
    // once, through a span of 6 seconds.

    SolidColorBrush brush = new SolidColorBrush(Colors.Yellow);
    p.Background = brush;
    ColorAnimation ca1 = new ColorAnimation()
    {
            From = Colors.Yellow,
            To = Colors.White,
            Duration = new Duration(TimeSpan.FromSeconds(6.0)),
            RepeatBehavior = new RepeatBehavior(1),
            AutoReverse = false,
    };

    brush.BeginAnimation(SolidColorBrush.ColorProperty, ca1);

回答by Developer

It is possible odd thing but my solution is to use both methods:

这可能是奇怪的事情，但我的解决方案是同时使用这两种方法：

Storyboard.SetTargetName(DA, myObjectName);

Storyboard.SetTarget(DA, myRect);

sb.Begin(this);

In this case there is no error.

在这种情况下，没有错误。

Have a look at the code where I have used it.

看看我使用它的代码。

 int n = 0;
        bool isWorking;
        Storyboard sb;
        string myObjectName;
         UIElement myElement;

        int idx = 0;

        void timer_Tick(object sender, EventArgs e)
        {
            if (isWorking == false)
            {
                isWorking = true;
                try
                {
                      myElement = stackObj.Children[idx];

                    var possibleIDX = idx + 1;
                    if (possibleIDX == stackObj.Children.Count)
                        idx = 0;
                    else
                        idx++;

                    var myRect = (Rectangle)myElement;

                   // Debug.WriteLine("TICK: " + myRect.Name);

                    var dur = TimeSpan.FromMilliseconds(2000);

                    var f = CreateVisibility(dur, myElement, false);

                    sb.Children.Add(f);

                    Duration d = TimeSpan.FromSeconds(2);
                    DoubleAnimation DA = new DoubleAnimation() { From = 1, To = 0, Duration = d };

                    sb.Children.Add(DA);
                    myObjectName = myRect.Name;  
                   Storyboard.SetTargetName(DA, myObjectName);
                   Storyboard.SetTarget(DA, myRect);

                    Storyboard.SetTargetProperty(DA, new PropertyPath("Opacity"));

                    sb.Begin(this);

                    n++;
                }
                catch (Exception ex)
                {
                    Debug.WriteLine(ex.Message + "   " + DateTime.Now.TimeOfDay);
                }

                isWorking = false;
            }
        }