Cannot get image dimensions with Image control!

04-24-2008 3:54 PM |

This has been covered before but I am not sure if an official bug has been reported. I need this functionality and I am hoping it will be fixed by the next release (Beta 2?)!

The Xaml:

<UserControl x:Class="Test.Page"
    xmlns="http://schemas.microsoft.com/client/2007"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Width="100" Height="300">
    <Grid x:Name="LayoutRoot" Background="Black">
        <Image x:Name="MyImage" Source="/images/yellowlily1.jpg" MaxWidth="300"/>
    </Grid>
</UserControl>

The code beside:

public Page()
{
    InitializeComponent();
   
    MyImage.MouseLeftButtonDown += (sender, e) => {
        HtmlPage.Window.Alert("MouseLeftButtonDown" + ": " + MyImage.Height.ToString() + ":" + MyImage.MaxWidth.ToString() + ":" + MyImage.ActualHeight.ToString() + ":" + MyImage.ActualWidth.ToString() + ":" + MyImage.RenderSize.ToString());
    };

    MyImage.Loaded += (sender, e) => {
        HtmlPage.Window.Alert("Loaded" + ": " + MyImage.Height.ToString() + ":" + MyImage.MaxWidth.ToString() + ":" + MyImage.ActualHeight.ToString() + ":" + MyImage.ActualWidth.ToString() + ":" + MyImage.RenderSize.ToString());
    };
}

The result:

Loaded: Nan:300:0:0:0,0
MouseLeftButtonDown: 66:300:66:88:88,66 

There doesn't seem to be a way of getting the image dimensions on image load. Occasionally the Loaded event will give the right dimensions.

I also tried BitmapImage class -

The Xaml:

<UserControl x:Class="Test.Page"
    xmlns="http://schemas.microsoft.com/client/2007"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Width="100" Height="300">
    <Grid x:Name="LayoutRoot" Background="Black">
        <Image x:Name="MyImage" MaxWidth="300"/>
    </Grid>
</UserControl>

The code beside:

public Page()
{
    InitializeComponent();
   
    BitmapImage bi = new BitmapImage();
    bi.UriSource = new Uri("/images/yellowlily1.jpg", UriKind.Relative);
    bi.DownloadProgress += (sender, e) => {
        if(e.Progress == 1)
            HtmlPage.Window.Alert("DownloadProgress:" + ": " + MyImage.Height.ToString() + ":" + MyImage.MaxWidth.ToString() + ":" + MyImage.ActualHeight.ToString() + ":" + MyImage.ActualWidth.ToString() + ":" + MyImage.RenderSize.ToString());
    };
   
    MyImage.MouseLeftButtonDown += (sender, e) => {
        HtmlPage.Window.Alert("MouseLeftButtonDown" + ": " + MyImage.Height.ToString() + ":" + MyImage.MaxWidth.ToString() + ":" + MyImage.ActualHeight.ToString() + ":" + MyImage.ActualWidth.ToString() + ":" + MyImage.RenderSize.ToString());
    };

    MyImage.Loaded += (sender, e) => {
        HtmlPage.Window.Alert("Loaded" + ": " + MyImage.Height.ToString() + ":" + MyImage.MaxWidth.ToString() + ":" + MyImage.ActualHeight.ToString() + ":" + MyImage.ActualWidth.ToString() + ":" + MyImage.RenderSize.ToString());
    };

    MyImage.Source = bi;
}

The result:

DownloadProgress: Nan:300:0:0:0,0 

What is weird here is that the downloadprogress event is called 3 times for e.Progress == 1 

All this is executing on the local machine (no server).

----------

All I want to do is put a simple border around the image. It doesn't seem possible since I cannot get the dimensions of the image. If there is a workaround for this, I would love to hear it! Note that I cannot specify the dimensions for the image or grid control since I want the image control to intelligently render the image.

Re: Cannot get image dimensions with Image control!

04-24-2008 5:10 PM |

A Kludgey workaround

internal void DrawBorderAroundImage()
{
    DispatcherTimer dispatcherTimer = new DispatcherTimer();
    dispatcherTimer.Interval = new TimeSpan(0, 0, 0, 0, 100);
   
    dispatcherTimer.Tick += (sender, e) => {
        ((DispatcherTimer)sender).Stop();
        HtmlPage.Window.Alert(MyImage.Height.ToString() + ":" + MyImage.MaxWidth.ToString() + ":" + MyImage.ActualHeight.ToString() + ":" + MyImage.ActualWidth.ToString() + ":" + MyImage.RenderSize.ToString());
    };   
}

This may / may not work since 100 msec is an approximation. But it illustrates the problem!

Please fix it soon.

Thanks

Wilfred Pinto
http://projectsilverlight.blogspot.com