WPF. Easiest way to move Image to (X,Y) programmat

问题:

Does anyone know of an easy way to animate a movement from an Image's current location to a new location (X,Y) using WPF animation with no XAML, 100% programmatically? And with no reference to "this" (with RegisterName etc).

I am trying to make an extension class for Image to do animation stuff on it. It is easy enough to change the width and height properties through animation, but after searching for location animation of an object it suddenly becomes more advanced.

As it is an extension class I will only have a reference to the actual Image object and the X and Y I want to move it to.

public static void MoveTo(this Image targetControl, double X, double Y, double Width, double Height){
 //code here
 ...
}

Update:

Thanks. Almost working. It seems The GetTop and GetLeft returns 'NaN' not explicitly set. Found the workaround in this post: Canvas.GetTop() returning NaN

public static void MoveTo(this Image target, double newX, double newY) {
                Vector offset = VisualTreeHelper.GetOffset(target);
                var top = offset.Y;
                var left = offset.X;
                TranslateTransform trans = new TranslateTransform();
                target.RenderTransform = trans;
                DoubleAnimation anim1 = new DoubleAnimation(0, newY - top, TimeSpan.FromSeconds(10));
                DoubleAnimation anim2 = new DoubleAnimation(0, newX - left, TimeSpan.FromSeconds(10));
                trans.BeginAnimation(TranslateTransform.YProperty, anim1);
                trans.BeginAnimation(TranslateTransform.XProperty, anim2);
        }

I had to swap two of the values (FROM) with 0. I assume that must be because in this context the upper left corner of the picture is the origin? But now it works.

回答1:

Try this:

public static void MoveTo(this Image target, double newX, double newY)
{
    var top = Canvas.GetTop(target);
    var left = Canvas.GetLeft(target);
    TranslateTransform trans = new TranslateTransform();
    target.RenderTransform = trans;
    DoubleAnimation anim1 = new DoubleAnimation(top, newY - top, TimeSpan.FromSeconds(10));
    DoubleAnimation anim2 = new DoubleAnimation(left, newX - left, TimeSpan.FromSeconds(10));
    trans.BeginAnimation(TranslateTransform.XProperty,anim1);
    trans.BeginAnimation(TranslateTransform.YProperty,anim2);
}

回答2:

Here it is... It changes the size and moves a MediaElement under the Canvas. Just input your parameters:

Storyboard story = new Storyboard();
DoubleAnimation dbWidth = new DoubleAnimation();
dbWidth.From = mediaElement1.Width;
dbWidth.To = 600;
dbWidth.Duration = new Duration(TimeSpan.FromSeconds(.25));

DoubleAnimation dbHeight = new DoubleAnimation();
dbHeight.From = mediaElement1.Height;
dbHeight.To = 400;
dbHeight.Duration = dbWidth.Duration;

story.Children.Add(dbWidth);
Storyboard.SetTargetName(dbWidth, mediaElement1.Name);
Storyboard.SetTargetProperty(dbWidth, new PropertyPath(MediaElement.WidthProperty));

story.Children.Add(dbHeight);
Storyboard.SetTargetName(dbHeight, mediaElement1.Name);
Storyboard.SetTargetProperty(dbHeight, new PropertyPath(MediaElement.HeightProperty));

DoubleAnimation dbCanvasX = new DoubleAnimation();
dbCanvasX.From = 0;
dbCanvasX.To = 5;
dbCanvasX.Duration = new Duration(TimeSpan.FromSeconds(.25));

DoubleAnimation dbCanvasY = new DoubleAnimation();
dbCanvasY.From = 0;
dbCanvasY.To = 5;
dbCanvasY.Duration = dbCanvasX.Duration;

story.Children.Add(dbCanvasX);
Storyboard.SetTargetName(dbCanvasX, mediaElement1.Name);
Storyboard.SetTargetProperty(dbCanvasX, new PropertyPath(Canvas.LeftProperty));

story.Children.Add(dbCanvasY);
Storyboard.SetTargetName(dbCanvasY, mediaElement1.Name);
Storyboard.SetTargetProperty(dbCanvasY, new PropertyPath(Canvas.TopProperty));

story.Begin(this);

<Viewbox Stretch="Uniform" StretchDirection="Both" SnapsToDevicePixels="True">
        <Grid  Width="640" Height="480" Name="MainLayout" SnapsToDevicePixels="True" Background="Black">
            <Canvas Width="640" Height="480" Name="MainCanvas" SnapsToDevicePixels="True">
                <MediaElement Height="171" HorizontalAlignment="Left" Name="mediaElement1" VerticalAlignment="Top" Width="337" LoadedBehavior="Manual" Margin="166,140,0,0" Canvas.Left="-162" Canvas.Top="-140" />
                <Button Canvas.Left="294" Canvas.Top="196" Content="Button" Height="23" Name="button1" Width="75" Click="button1_Click" />
            </Canvas>
        </Grid>
    </Viewbox>

UPDATE:

Instead of MediaElement use this line:

 <Rectangle Height="171" HorizontalAlignment="Left" Name="mediaElement1" VerticalAlignment="Top" Width="337"    Margin="166,140,0,0" Canvas.Left="-162" Canvas.Top="-140" Fill="{DynamicResource {x:Static SystemColors.MenuBarBrushKey}}" />

And don't forget to put the C# code to:

private void button1_Click(object sender, RoutedEventArgs e) {}

You can use MediaElement as well but you have to define a VideoClip to see something ;)

回答3:

This code is based on @DeanChalk's answer.

It moves an Image contained within a Canvas (RFID_Token) diagonally from the top-right to the bottom-left, positioned centrally over another Image within a Canvas (RFID_Reader).

<Canvas>
    <Canvas x:Name="RFID_Reader_Canvas">
        <Image x:Name="RFID_Reader" Source="RFID-Reader.png" Height="456" Width="682" Canvas.Left="37" Canvas.Top="524"/>
    </Canvas>
    <Canvas x:Name="RFID_Token_Canvas">
        <Image x:Name="RFID_Token" Source="RFID-Token.png" Height="268" Width="343" Canvas.Left="874" Canvas.Top="70"/>
    </Canvas>
</Canvas>

var StartX = Canvas.GetLeft(RFID_Token);
var StartY = Canvas.GetTop(RFID_Token);

var EndX = RFID_Reader.Width / 2 + Canvas.GetLeft(RFID_Reader) - StartX - (RFID_Token.Width / 2);
var EndY = RFID_Reader.Height / 2 + Canvas.GetTop(RFID_Reader) - StartY - (RFID_Token.Height / 2);

var AnimationX = new DoubleAnimation(0, EndX, TimeSpan.FromSeconds(1));
var AnimationY = new DoubleAnimation(0, EndY, TimeSpan.FromSeconds(1));

var Transform = new TranslateTransform();
RFID_Token_Canvas.RenderTransform = Transform;

Transform.BeginAnimation(TranslateTransform.XProperty, AnimationX);
Transform.BeginAnimation(TranslateTransform.YProperty, AnimationY);

回答4:

I kept having NaN or 0 values for my nested elements, here's a modified version of Danny's answer :

    public void MoveTo(Canvas canvas, FrameworkElement target, FrameworkElement destination)
    {
        Point oldPoint = target.TransformToAncestor(canvas).Transform(new Point(0, 0));
        Point newPoint = destination.TransformToAncestor(canvas).Transform(new Point(0, 0));

        var EndX = destination.Width / 2 + newPoint.X - oldPoint.X - (target.Width / 2);
        var EndY = destination.Height / 2 + newPoint.Y - oldPoint.Y - (target.Height / 2);

        TranslateTransform trans = new TranslateTransform();
        target.RenderTransform = trans;
        DoubleAnimation anim1 = new DoubleAnimation(0, EndX, TimeSpan.FromSeconds(0.3));
        DoubleAnimation anim2 = new DoubleAnimation(0, EndY, TimeSpan.FromSeconds(0.3));
        trans.BeginAnimation(TranslateTransform.XProperty, anim1);
        trans.BeginAnimation(TranslateTransform.YProperty, anim2);
    }

回答5:

Please find a solution that uses the Left and Top properties of Canvas for the extension method. See the following code:

    public static void MoveTo(this Image target, Point newP)
    {

        Point oldP = new Point();
        oldP.X = Canvas.GetLeft(target);
        oldP.Y = Canvas.GetTop(target);

        DoubleAnimation anim1 = new DoubleAnimation(oldP.X, newP.X, TimeSpan.FromSeconds(0.2));
        DoubleAnimation anim2 = new DoubleAnimation(oldP.Y, newP.Y , TimeSpan.FromSeconds(0.2));

        target.BeginAnimation(Canvas.LeftProperty , anim1);
        target.BeginAnimation(Canvas.TopProperty, anim2);

    }