change image source by xaml code?

How can I开发者_运维问答 change an image source continuously by xaml codes??

in case of in-place:

<Image Source="smiley_stackpanel.png" Stretch="Fill"/>

if in style:

<Style TargetType="Image">
    <Setter Property="Source" Value="c:\asd.jpg" />
</Style>

This is mostly from memory, so there may be a small bug, but basically, you'll want to put in two images, and animate their Opacity values:

<Grid>

    <Image x:Name="imgOne" Source="image1.png">
        <Image.Triggers>
            <EventTrigger RoutedEvent="Image.Loaded">
                <BeginStoryboard>
                    <Storyboard>
                        <DoubleAnimation
                            Storyboard.TargetName="imgOne"
                            Storyboard.TargetProperty="(Image.Opacity)"
                            To="0" 
                            Duration="0:0:1" 
                            AutoReverse="True"                                
                            RepeatBehavior="Forever" />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>
        </Image.Triggers>    
    </Image>
    <Image x:Name="imgTwo" Source="image1.png" Opacity="0">
        <Image.Triggers>
            <EventTrigger RoutedEvent="Image.Loaded">
                <BeginStoryboard>
                    <Storyboard>
                        <DoubleAnimation
                            Storyboard.TargetName="imgTwo"
                            Storyboard.TargetProperty="(Image.Opacity)"
                            To="1" 
                            Duration="0:0:1" 
                            AutoReverse="True"                                
                            RepeatBehavior="Forever" />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>
        </Image.Triggers>    
    </Image>


</Grid>

Strictly speaking, you probably don't need the first animation unless the second image has some transparent areas or does not fully cover the first.

Also, YMMV - this will be a bit of a resource eater, since it is happening so quickly and often.