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1

I've done this task before within repeaters and it has worked. However I can't get the below to work for me in a normal webforms page. The images appear as broken links and breakpoints I put in the codebehind are not triggered.

(in the aspx file)

<asp:ImageButton ID="ImageButton1" runat="server" ImageUrl='<%# GetImageDirectory()%>btnRunReport.png'  />

(codebehind)

public string GetImageDirectory()
{
    return "~/App_Variants/LBSX/images/";
}

This is the second method I've tried, in the other one I tried passing the imagename through as a string, and it would return the entire link that way. Still no luck!

Any thoughts?

Thanks!

[EDIT] Thanks for the help everyone. In the end after the handy hints I found a recursive snippet which did the trick as follows:

private void UpdateImages(Control Parent)
{
    foreach (Control c in Parent.Controls)
    {
        ImageButton i = c as ImageButton;
        if (i != null)
        {
            i.ImageUrl = "~/App_Variants/LBSX/images/" + i.ImageUrl;
        }
        if (c.HasControls())
        {
            UpdateImages(c);
        }
    }
}

protected void Page_Load(object sender, EventArgs e)
{
    UpdateImages(Page);
    ...

Hope it helps someone else.

Cheers

share|improve this question
<%# - call on data-bind event. <%= - call in render (normal usage). you're looking for <%= – RPM1984 Jul 19 '10 at 5:54
Yes, sorry I also have tried the <%= but still no breakpoint triggered. What else could I be doing wrong? – Glinkot Jul 19 '10 at 6:23
Also, when I view source on the page, the control shows the src as: src="&lt;%=GetImageDirectory()%20%>" rather than trying to pass whatever it calculates. Maybe there's a clue there – Glinkot Jul 19 '10 at 6:42

2 Answers

up vote 4 down vote accepted

First, just like Zachary mentioned, you're using the code block for data binding.

Second, as you've already tried, using an inline expression (<%= %>) won't work either in your case, since you can't use an inline expression for any property of a server-tag.

What you could do instead is defining an image button using HTML syntax, omitting the runat="server" tag, and use the inline expression to get your image's URL:

<input type="image" src="<%= GetImageDirectory() %>btnRunReport.png" name="image" />

What an inline expression does is, it calls Response.Write() with the value between <%= %> as the parameter, e.g. <%= this.MyVar %> is Response.Write(this.MyVar).

share|improve this answer
Ok, thanks for that. What I'm trying to do is put a custom directory (depending on certain conditions) in front of the image name. So in one case it may be images3/picture.jpg and in others it would be images4/picture.jpg. I'm not using themes for various reasons. Is there any way in the codebehind I could achieve the same by doing something like: First, set imageURL at designtime to 'picture.jpg' without path Then for each Imagebutton in (whatever the page object is) ImageUrl = "mydirectory" + existing imageurl Would that be workable do you think? Thanks for your time! – Glinkot Jul 19 '10 at 7:14
Thanks to your guidance I've now managed to solve this. Ended up iterating through the controls as mentioned and putting the path at the front. Works a charm! I will add code to the question for others reference. – Glinkot Jul 19 '10 at 7:32
1  
I'm glad you could solve this. I've managed to write the code for iterating through the controls; if somebody's interested, you can find the mentioned code here: hpaste.org/fastcgi/hpaste.fcgi/view?id=27788#a27788 – Giu Jul 19 '10 at 7:47
Thanks for that, much appreciated mate. Note that the one I put above is recursive whereas yours seems to be nested to two levels. Not sure if it ever goes below two levels, mind you... :) – Glinkot Jul 19 '10 at 23:18
up vote 2 down vote

Your syntax is for data binding, <%# %>. If you are just trying to do inline c#, you should use <%= %>.

share|improve this answer
Actually I should have mentioned, I've tried that also and no luck still! Good point though, I did find various people saying that when I was searching forums etc. – Glinkot Jul 19 '10 at 6:22

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