Re: Scalling Silverlight

12-13-2008 9:46 PM |

I wrote a little animation helper a while back that could be useful to you (looking at it now, it could use some polishing, but should get you started).  It does have some base elements in Xaml, but the actual control of the animation is done in C#.  I use it for doing simple on-the-fly scaling and some color shifting.

The Xaml:

<UserControl x:Class="Helpers.animation"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="400" Height="300">
    <UserControl.Resources>
        <Storyboard x:Name="animZoom">
            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleX)">
                <SplineDoubleKeyFrame x:Name="kf_animZoomOut_startXScale" KeyTime="00:00:00" Value="1"/>
                <SplineDoubleKeyFrame x:Name="kf_animZoomOut_endXScale" KeyTime="00:00:00.300" Value="1"/>
            </DoubleAnimationUsingKeyFrames>
            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00"  Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleY)">
                <SplineDoubleKeyFrame x:Name="kf_animZoomOut_startYScale" KeyTime="00:00:00" Value="1"/>
                <SplineDoubleKeyFrame x:Name="kf_animZoomOut_endYScale" KeyTime="00:00:00.300" Value="1"/>
            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
        <Storyboard x:Name="animColorShift">
            <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="(Panel.Background).(SolidColorBrush.Color)">
                <SplineColorKeyFrame x:Name="kf_animColorShift_startColor" KeyTime="00:00:00" Value="#FFFFFFFF"/>
                <SplineColorKeyFrame x:Name="kf_animColorShift_endColor" KeyTime="00:00:01" Value="#FFD41717"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>
    </UserControl.Resources>
    <Grid x:Name="LayoutRoot" Background="White">

    </Grid>
</UserControl>

 The code-behind:

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;

namespace Helpers
{
    sealed public partial class animation : UserControl
    {
        private bool _zoomRelativeLock = false;
        private bool _zoomAbsoluteLock = false;
        private bool _colorShiftLock = false;

        public event EventHandler ColorShiftAnimationComplete;
        public event EventHandler ZoomComplete;
        public void OnZoomComplete(EventArgs e)
        {
            if (ZoomComplete != null)
                ZoomComplete(this, e);
        }
        public void OnColorShiftAnimationComplete(EventArgs e)
        {
            if (ColorShiftAnimationComplete != null)
            {
                ColorShiftAnimationComplete(this, e);
            }
        }
        
        public animation()
        {
            InitializeComponent();
        }

        public void ZoomRelative(UIElement c, double relativeScale)
        {
            if (!_zoomRelativeLock)
            {
                _zoomRelativeLock = true;
                Initialize(animZoom, c);
                kf_animZoomOut_endXScale.Value = kf_animZoomOut_startXScale.Value * relativeScale;
                kf_animZoomOut_endYScale.Value = kf_animZoomOut_startYScale.Value * relativeScale;
                animZoom.Completed += new EventHandler(animZoom_Completed);
                Storyboard.SetTarget(animZoom, c);
                animZoom.Begin();
            }
        }

        void animZoom_Completed(object sender, EventArgs e)
        {

            animZoom.Completed -= new EventHandler(animZoom_Completed);
            kf_animZoomOut_startXScale.Value = kf_animZoomOut_endXScale.Value;
            kf_animZoomOut_startYScale.Value = kf_animZoomOut_endYScale.Value;
            _zoomRelativeLock = false;
            _zoomAbsoluteLock = false;
            OnZoomComplete(new EventArgs());
        }

        public void ZoomAbsolute(UIElement c, double absoluteScale)
        {
            if (!_zoomAbsoluteLock)
            {
                _zoomAbsoluteLock = true;
                Initialize(animZoom, c);
                kf_animZoomOut_endXScale.Value = kf_animZoomOut_endYScale.Value = absoluteScale;
                animZoom.Completed += new EventHandler(animZoom_Completed);
                Storyboard.SetTarget(animZoom, c);
                animZoom.Begin();
            }
        }

        public void ColorShift(Panel c, Color nextColor, int DurationInMilliseconds)
        {
            if (!_colorShiftLock)
            {
                if (animColorShift.GetCurrentState() != ClockState.Stopped)
                    animColorShift.Stop();
                _colorShiftLock = true;
                animColorShift.Completed += new EventHandler(animColorShift_Completed);
                Storyboard.SetTarget(animColorShift, c);
                kf_animColorShift_startColor.Value = ((SolidColorBrush)c.Background).Color;
                kf_animColorShift_endColor.Value = nextColor;
                kf_animColorShift_endColor.KeyTime = KeyTime.FromTimeSpan(new TimeSpan(0, 0, 0, 0, DurationInMilliseconds));
                animColorShift.Begin();
            }
        }
        
        void animColorShift_Completed(object sender, EventArgs e)
        {
            animColorShift.Stop();
            animColorShift.Completed -= new EventHandler(animColorShift_Completed);
            _colorShiftLock = false;
            OnColorShiftAnimationComplete(new EventArgs());
        }

        private void Initialize(Storyboard sb, UIElement c)
        {
            if (sb.GetCurrentState() != ClockState.Stopped)
                sb.Stop();
            TransformGroup tg = new TransformGroup();
            tg.Children.Add(new ScaleTransform());
            tg.Children.Add(new SkewTransform());
            tg.Children.Add(new RotateTransform());
            tg.Children.Add(new TranslateTransform());
            c.RenderTransform = tg;
            c.RenderTransformOrigin = new Point(.5, .5);
        }
    }
}