Write applications that take arguments

C# has a nice feature that VB.NET lacks: the ability to define a Main procedure that takes an array of strings, each one containig one of the arguments passed on the command line. It’s easy to mimick this feature in VB, though.

In fact, while the Command function is still supported in VB.NET, you can retrieve command-line arguments more easily with the GetCommandLineArgs static method of the System.Environment class. This method parses the command-line text and returns individual arguments in an array of strings. Therefore you can have the “real” Sub Main procedure pass this array to a second Main procedure, which is where the real processing occurs. For example, the following code shows how you can build a console application that takes exactly two arguments:

Module Module1    ' the "official" entry point     Sub Main()        ' call the Main with arguments        Main(Environment.GetCommandLineArgs())    End Sub    ' the "real" Main procedure    Private Sub Main(ByVal args() As String)        ' suppose that we expect two arguments, but there is always an        ' extra argument that contains the EXE filename        If args Is Nothing OrElse args.Length <> 3 Then            Console.WriteLine("Syntax error.")        Else            ' use the arguments args(1) and args(2)            ' ...        End If    End SubEnd Module

Keep in mind that the first command-line argument is always the complete filename of the running executable, therefore the first argument is args(1).

If you still need the entire command-line, without it being split in arguments, you can use the Environment.CommandLine static method.UPDATE: Richard Deeming and Burton Rodman wrote us to point at an alternative, and much cleaner way, to have your VB app take arguments. You just need to define a Sub Main that takes an array of strings:

Sub Main(ByVal args() As String)     ' Display arguments passed to the application    Dim s As String     For Each s In args        Console.WriteLine(s)    NextEnd FunctionThe args array will be filled with the command-line arguments, _    excluding the name of the executable.

Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

microsoft careers

Top Careers at Microsoft

Microsoft has gained its position as one of the top companies in the world, and Microsoft careers are flourishing. This multinational company is efficiently developing popular software and computers with other consumer electronics. It is a dream come true for so many people to acquire a high paid, high-prestige job

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a

chrome os developer mode

How to Turn on Chrome OS Developer Mode

Google’s Chrome OS is a popular operating system that is widely used on Chromebooks and other devices. While it is designed to be simple and user-friendly, there are times when users may want to access additional features and functionality. One way to do this is by turning on Chrome OS