Dynamic asp form via cs (c#) code

  • Thread starter Thread starter dpfollmer
  • Start date Start date
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dpfollmer

I am currently designing a ASP.NET form for contacts which displays a
picture depending on which contact is being viewed. This code works
perfectly thus far, but I want to add an if-case for when the picture
does not exist.

In english it would be something like this:

If file exists ("../picture_id.jpg")
Then display image source (<img src='pictures/picture_id.jpg'>
Else diplay nothing (<br><br>)

How do I verify that a file exists on the web server using c#?

Here is a "cleaned" snippet from my current .cs file:
protected Literal imageSRC;
protected override void MyPageLoad(object src, EventArgs e)
{
int picture_id = -1;

try
{
picture_id = Convert.ToInt32(Request["picture_id"]);
}
catch
{
picture_id = -1;
}

if (picture_id > 0)
// <summary> Add if image exists code here </summary>
{
imageSRC.Text = "<img src='contacts_pictures/" + picture_id +
"_Thumb.jpg'>";
}
}
Thanks in advance,

David
 
Your "english" version is pretty close to the real version.

if (System.IO.File.Exists(PathToFile))
{
// do something
}
else
{
// do something else
}


you'll need to get the full path to the file, that is
c:\inetpub\wwwroot\xxxx or whatever it might be, so it would be something
like:

string picturePath = string.Format("/pictures/picture_{0}.jpg", pictureId);
if (System.IO.File.Exists(Server.MapPath(picturePath))
{
img.Src = picturePath;
}
else
{
img.Src = "pictures/default.jpg";
}

notice that I'm not doing the ugly text = "<img src=....>" that you are,
but rahter I'm using an image server control and simply setting the Src
property.

Karl

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http://www.openmymind.net/faq.aspx - unofficial newsgroup FAQ (more to
come!)


I am currently designing a ASP.NET form for contacts which displays a
picture depending on which contact is being viewed. This code works
perfectly thus far, but I want to add an if-case for when the picture
does not exist.

In english it would be something like this:

If file exists ("../picture_id.jpg")
Then display image source (<img src='pictures/picture_id.jpg'>
Else diplay nothing (<br><br>)

How do I verify that a file exists on the web server using c#?

Here is a "cleaned" snippet from my current .cs file:
protected Literal imageSRC;
protected override void MyPageLoad(object src, EventArgs e)
{
int picture_id = -1;

try
{
picture_id = Convert.ToInt32(Request["picture_id"]);
}
catch
{
picture_id = -1;
}

if (picture_id > 0)
// <summary> Add if image exists code here </summary>
{
imageSRC.Text = "<img src='contacts_pictures/" + picture_id +
"_Thumb.jpg'>";
}
}
Thanks in advance,

David
Click to expand...
 
When you use the img.source instead of the long way I used (<img
src=...), how do you call this in the aspx file?

I currently use something like:
<asp:Literal id="ImageSrc" runat="server"/>

Thanks,
David
 
<img id="someId" runat="server" />

then declare it as

Protected someId as HtmlImage 'vb.net
protected HtmlImage someId //c#

Karl
 
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