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New to ASP.NET checking if image exists vb

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User394159258 posted

Completely new to ASP.net so bear with me...

Page Language="vb"

Microsoft .NET Framework Version:2.0.50727.3603; ASP.NET Version:2.0.50727.3082

I want to check on the server for the existance of an image, then if it does exist, display the image wrapped in other code.

eg

if "/images/name.jpg" exists then

<div><img src="/images/name.jpg"></div>

else

Do nothing.

Seems really simple to me but NOTHING I have tried has worked (compilation errors).

I've tried examples using system.io, DIM stuff with 'FileInfo', Set fs.

FileInfo examples produce 'not defined' errors, 'Set' says it's outdated and not used anymore and so on.

Other examples I've seen I couldn't attempt at trying since they were whole pages of code. Surely it can't be THAT difficult, can it?

TIA

Tuesday, January 19, 2010 12:15 PM

Answers

User-1772898816 posted

<%@ Page Language="VB" %>
<%@ Import Namespace="System.IO" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
        DoesFileExist("Images/logo.gif")
    End Sub
    
    Function DoesFileExist(ByVal strFileName As String) As Boolean
        If File.Exists(Server.MapPath(strFileName)) Then
            image1.ImageUrl = strFileName
        End If
    End Function
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <asp:Image ID="image1" runat="server" />
    </div>
    </form>
</body>
</html>

You can do something like what is above except use an array or a list of the image names and then pass them into the function and then test.

Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM

Wednesday, January 20, 2010 7:59 AM

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User1006193418 posted

Hi,

You may also be interested in IMG tag's onerror event. Please refer to these links for demoes and description:

http://docstore.mik.ua/orelly/web/jscript/refp_171.html

http://www.logiclabz.com/javascript/replacement-image-in-html-img-tag-using-onerror-property.aspx.

Best Regards,
Shengqing Yang
- Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
Friday, January 22, 2010 5:38 AM

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User-1772898816 posted

http://www.vb-helper.com/howto_net_file_exists.html

Tuesday, January 19, 2010 12:34 PM
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User-507673006 posted

You could try using an asp:Image control like the following:

<asp:Image ID="Image1" runat="server" />

Then use something along the lines of this in your code-behind:

Dim imageStr As String = "~/images/name.jpg" If System.IO.File.Exists(imageStr) Then Image1.ImageUrl = "~/images/name.jpg" End If

I havn't tested this but something along those lines should work...
Tuesday, January 19, 2010 12:39 PM
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User394159258 posted

http://www.vb-helper.com/howto_net_file_exists.html This produces the error: BC30289: Statement cannot appear within a method body. End of method assumed.

And

Dim imageStr As String = "~/images/name.jpg"
If System.IO.File.Exists(imageStr) Then
Image1.ImageUrl = "~/images/name.jpg"
End If

<asp:Image ID="Image1" runat="server" />

Runs ok but doesn't product anything at all on the page.

Wednesday, January 20, 2010 4:09 AM

User-68639941 posted

hi,

refer below code

	if (System.IO.File.Exists(Server.MapPath("~/FOLDER03.ICO")))
		{
			//set the image path , to access the html img control at server-side it should be marked with runat="server" attribute
		}

Wednesday, January 20, 2010 5:08 AM

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User394159258 posted

I've got the following working:

<%@ Import Namespace="System.IO" %>
<script language="VB" runat="server">
   Dim strFileThatExists As String = "/frontads/meindl.jpg"

   Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
       litFileThatExists.Text = DoesFileExist(strFileThatExists)
   End Sub

    Function DoesFileExist(strFileName As String) As Boolean
       Dim strFullPath As String
       If InStr(strFileName, ":") <> 0 Then
           strFullPath = strFileName
       Else
           strFullPath = Server.MapPath(strFileName)
       End If
       DoesFileExist = File.Exists(strFullPath)
   End Function
</script>

<%= File.Exists(Server.MapPath(strFileThatExists)) %>

BUT I want to add an, if File.Exists == True then

<div><img src="strFileThatExists1.jpg"/></div>

(building up to checking for multiple images in sequence, 1.jpg, 2.jpg etc)

Wednesday, January 20, 2010 5:21 AM