Solved

check if image exists

Posted on 2007-11-22
7
3,838 Views
Last Modified: 2013-12-16
In ASP.NET 2.0 with C# I have a page with an <asp:Image> control.
I have the img.ImageUrl that contain the link for the image.
I want to make a check if the image exists. How do I do this check?
thankyou
Anat
0
Comment
Question by:ANAT2403
7 Comments
 
LVL 10

Expert Comment

by:Oliver Amaya
ID: 20335088
Hi, this is one way of doing it:
// for relative URL
bool imgFound = System.IO.File.Exists(Server.MapPath(img.ImageUrl));
 
// for absolute URL
bool imgFound = System.IO.File.Exists(img.ImageUrl);

Open in new window

0
 
LVL 11

Expert Comment

by:cmhunty
ID: 20335119
If the URL is not local, you can use something like this (sorry, it's in VB.NET but may give you an idea):

    Private Function ImageExists(ByVal strURL As String) As Boolean
        Dim blExists As Boolean = True
        Try
            Dim req As HttpWebRequest = WebRequest.Create(strURL)
            Dim res As HttpWebResponse = req.GetResponse
        Catch ex As Exception
            blExists = False
        End Try
        Return blExists
    End Function
0
 

Author Comment

by:ANAT2403
ID: 20335211
Hi joex911
this is my imgurl:
http://192.168.1.101/appsrv/vg_paint?s=main&w=110&bg=bg1&h=80&q=100&f=models/79942.jpg
this return an image
and this does not return anything:
http://192.168.1.101/appsrv/vg_paint?s=main&w=110&bg=bg1&h=80&q=100&f=models/5.jpg
your first suggestion for relative URL returned an error on both cases and you second returned false for both cases. Do you have another suggestion?
Hi cmhunty
I could not define HttpWebRequest . What using do I need for this?
Thankyou
Anat

0
Master Your Team's Linux and Cloud Stack

Come see why top tech companies like Mailchimp and Media Temple use Linux Academy to build their employee training programs.

 
LVL 11

Expert Comment

by:cmhunty
ID: 20335389
Use System.Net. With my limited knowledge of C#, I tried to recreate but struggled. Maybe someone else could convert?
0
 
LVL 10

Accepted Solution

by:
Oliver Amaya earned 250 total points
ID: 20335466
With the method's I put up the image has to be local on the server. I can convert cmhunty code to c# though
private bool ImageExists(string strURL)
{
  bool blExists = true
  try
  {
    System.Net.HttpWebRequest req = System.Net.WebRequest.Create(strURL);
    System.Net.HttpWebResponse res = req.GetResponse();
  }
  Catch(Exception ex)
  {
    blExists = false;
  }
  return blExists;
}

Open in new window

0
 
LVL 11

Assisted Solution

by:cmhunty
cmhunty earned 250 total points
ID: 20335512
Managed to convert to C# - seems you can't convert HttpWebRequest to WebRequest in C# but can in VB.NET

private bool ImageExists(string strURL)
{
  bool blExists = true;
  try
  {
      WebRequest req = WebRequest.Create(strURL);
      WebResponse res = req.GetResponse();

  }
  catch(Exception ex)
  {
    blExists = false;
  }
  return blExists;
}
0
 
LVL 29

Expert Comment

by:Göran Andersson
ID: 20335663
VB.NET allows an implicit conversion, but only if you don't use Option Strict.

In C# you always have to do an explicit cast if the compiler can't tell that the cast is safe:

HttpWebRequest req = (HttpWebRequest)WebRequest.Create(strURL);
0

Featured Post

Master Your Team's Linux and Cloud Stack!

The average business loses $13.5M per year to ineffective training (per 1,000 employees). Keep ahead of the competition and combine in-person quality with online cost and flexibility by training with Linux Academy.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction This article shows how to use the open source plupload control to upload multiple images. The images are resized on the client side before uploading and the upload is done in chunks. Background I had to provide a way for user…
A long time ago (May 2011), I have written an article showing you how to create a DLL using Visual Studio 2005 to be hosted in SQL Server 2005. That was valid at that time and it is still valid if you are still using these versions. You can still re…
Two types of users will appreciate AOMEI Backupper Pro: 1 - Those with PCIe drives (and haven't found cloning software that works on them). 2 - Those who want a fast clone of their boot drive (no re-boots needed) and it can clone your drive wh…

830 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question