Get rid of the style="border-width:0px" from the Image tag.
I do have pet projects in which I try to get every single nitty gritty detail right. And then it bothers me that by default the ASP.NET Image control adds a style="border-width:0px" to the rendered image tag even though I never asked for it. Not even does it add the style attribe without asking, it doesn't offer a way to get rid of it! You can get rid of it though!
ControlAdapters
Fortunately ASP.NET does come with control adapters, so we can do something about it. Lets first create a new .browser file in the App_Browser directory to tie up our control adapter to the rendering of the Image control. The contents should like lik this:
<?xml version="1.0" encoding="utf-8" ?>
<browsers>
<browser refID="Default">
<controlAdapters>
<adapter
controlType="System.Web.UI.WebControls.Image"
adapterType="WMB.VirtueleKassa.WebControls.ImageAdapter" />
</controlAdapters>
</browser>
</browsers>Next thing to do is to create the WMB.VirtueleKassa.WebControls.ImageAdapter. Create a new class file in the App_Code directory. The code for the ImageAdapter should look like this:
!! have a look at the comment of RichardD! He proposed a better solution !!
using System;
using System.IO;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.Adapters;
namespace WMB.VirtueleKassa.WebControls {
public class ImageAdapter : WebControlAdapter {
public ImageAdapter() {
}
protected override void RenderBeginTag(HtmlTextWriter writer) {
Image img = this.Control as Image;
if (img.BorderWidth.IsEmpty) {
string origTag = string.Empty;
using (StringWriter sw = new StringWriter())
using (HtmlTextWriter hw = new HtmlTextWriter(sw)) {
base.RenderBeginTag(hw);
hw.Flush();
hw.Close();
origTag = sw.ToString();
}
string newTag = origTag.Replace("border-width:0px;", "");
newTag = newTag.Replace(" style=\"\"", "");
writer.Write(newTag);
}
else {
base.RenderBeginTag(writer);
}
}
protected override void RenderEndTag(HtmlTextWriter writer) {
}
protected override void RenderContents(HtmlTextWriter writer) {
}
}
}And thats it! If you do apply a width yourself, the tag will be saved, and so will any other style tags. Only if, after the deletion of the border-width:0px; the style attribute remains empty, the complete style attribute will be removed as well. Have a look at the source of this page to see the result.
Regards,
Wesley