API Programming

I was creating an application in Visual Basic the other day and I couldn’t remember how to check to see if a file exists, so I thought I would do a quick example to see if a file exitsts. If the file exists, the program will continue on, however, if the file doesn’t exist you will get a message box saying that the file does not exist, and the application will exit.

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If System.IO.File.Exists("C:\MyDocs\MyFile.txt") = False Then
   MsgBox("Field does not exist!", MsgBoxStyle.Critical, "File Not Found")
   Application.Exit()
End If

If you have an Imports System.IO call in your program, then you can shorten the method call by deleting the System.IO class name, which would give you.

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If File.Exists("C:\MyDocs\MyFile.txt") = False Then
   MsgBox("Field does not exist!", MsgBoxStyle.Critical, "File Not Found")
   Application.Exit()
End If

This method call is supported in .NET Framework version 3.5, 3.0, 2.0, 1.1, and 1.0.