Run an app from a ListBox

I have an app in vb.net that pulls a list of files from a directory and displays them in a ListBox. These files could be .pdf, .mov, .exe or .docx files. When I select a file from the list, I want it to either display the contents of the .pdf and .docx files or run the .exe and .mov files.

The code builds the ListBox properly, but when I select a file, I get the following error message:

{"An error occurred trying to start process 'F:\WoodWorking\Adirondack_chair _woodrequirements.docx' with working directory 'F:\Woodworking\WWDISPLAY\WoodWorkingFiles\bin\Debug\net6.0-windows'. The specified executable is not a valid application for this OS platform."}

I get the same error message regardless of file type.

Attached is the code in its entirety any working assistance would be greatly appreciated.


Imports System.IO

Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

End Sub

Private Sub WoodWorking_SelectedIndexChanged(sender As Object, e As
EventArgs) Handles WoodWorking.SelectedIndexChanged
End Sub

Private Sub BtnStart_Click(sender As Object, e As EventArgs) Handles
BtnStart.Click
Dim finfo As New IO.DirectoryInfo("F:\WoodWorking" )
WoodWorking.Items.Clear()
For Each fi In finfo.GetFiles("*.*" )
WoodWorking.Items.Add(Path.GetFileName(fi.FullName))
Next
End Sub

Private Sub WoodWorking_DoubleClick(sender As Object, e As EventArgs) Handles
WoodWorking.DoubleClick
Dim fullPath = Path.Combine("F:\WoodWorking" ,
WoodWorking.SelectedItem.ToString())
System.Diagnostics.Process.Start(fullPath)
End Sub

End Class

You'll need to check the file extension of the selected file and then run the appropriate code to either display the file or launch an EXE.

Do you want to display the contents of the Word or PDF file in a control on your Winform? Similarly, display the video on your form or are you looking to launch Word to display the Document, a PDF viewer for the PDF and a video player for the .mov file?

Possibly useful links:

https://www.vbforums.com/showthread....efault-program

https://stackoverflow.com/questions/...file-in-vb-201

I have used this same basic concept on another project, the only difference is that I included a Textbox to enter a filename to lookup. The app worked as expected, I didn't need to set up for any of the file extensions. When you selected a file, regardless of the extension, it ran it. I went back to the older project, refitted it for the new directory and it runs perfectly. So I'll just copy the code from the older app and rewrite it to fitt the new criteria.

I'm not sure why it wouldn't run as originally written but someday I'll work it out.

Thanks for the reply.

The links provided in post #3 probably address this but the issue is almost certainly due to different default behaviour between .NET Framework and .NET Core (.NET 5 and later are based on .NET Core). In order to open a data file in its default application using Process.Start, you need to set UseShellExecute to True. That is the default in .NET Framework but not in .NET Core. You will need to use an overload of Process.Start that takes a ProcessStartInfo as an argument and set UseShellExecute to True on that object.

Quote:

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Originally Posted by Darby

I have used this same basic concept on another project, the only difference is that I included a Textbox to enter a filename to lookup. The app worked as expected, I didn't need to set up for any of the file extensions. When you selected a file, regardless of the extension, it ran it. I went back to the older project, refitted it for the new directory and it runs perfectly. So I'll just copy the code from the older app and rewrite it to fitt the new criteria.

I'm not sure why it wouldn't run as originally written but someday I'll work it out.

Thanks for the reply.

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Ok, this

Quote:

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I select a file from the list, I want it to either display the contents of the .pdf and .docx files or run the .exe and .mov files.

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was a bit confusing as to whether you wanted to display it embedded on your form or launch the default app for the file type. That is why I asked the question.

jmcilhinney's answer will get you where you want to go.

I want to launch the default app. I rewrote the original code to fit the new app and it works perfectly. the only change I made was changing the directory in finfo. I also agree with jmcilhinney's answer. Thanks to all who responded.