CODEWITHSUNDEEP
vb.netfilenames
Maz
Maz

Reputation: 59

VB Finding Pattern in filename

I have 2 variables:

    Dim filename as string = "Test2020.csv"
    Dim fileSearch as string = "Test*.csv"

Filename is the name of the file and file search is the pattern that was used to find it.

I am in a situation where I need to check if the filename matches the pattern.

The way I was going to do it is take every string before the *: "Test" and everything after the *: ".csv" and check if the filename starts and ends with these. Is there an easier and simpler way to find if one string pattern matches the other.

Please note, I am comparing 2 strings and not trying to locate a file in a directory.

Upvotes: 0

Views: 507

Answers (3)

Idle_Mind
Idle_Mind

Reputation: 39152

VB.Net does have the LEGACY Like Operator:

Compares a string against a pattern.

You can't use it in .NET Core or .NET Standard, though:

The Like operator is currently not supported in .NET Core and .NET Standard projects.

If that doesn't bother you, then here's an example:

Dim filename As String = "Test2020.csv"
Dim fileSearch As String = "Test*.csv"
If filename Like fileSearch Then
    Debug.Print("Passed the pattern test.")
Else
    Debug.Print("Did NOT pass the pattern test.")
End If

Upvotes: 0

Mary
Mary

Reputation: 15101

You can use String.StartWith() and String.EndsWith().

Private Function TestPatternMatch(FileName As String) As Boolean
    If FileName.StartsWith("Test") AndAlso FileName.EndsWith(".csv") Then
        Return True
    Else
        Return False
    End If
End Function

Usage:

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    Debug.Print(TestPatternMatch("Test2020.csv").ToString)
End Sub

Upvotes: 0

Jamie
Jamie

Reputation: 782

Try this:

This returns true:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim fileSearch As String = "Test1929.csv"
Dim FileNameMatch As Boolean = fileSearch Like "Test####[.]csv"
TextBox1.Text = FileNameMatch
End Sub

This returns false:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim fileSearch As String = "Testabcd.csv"
Dim FileNameMatch As Boolean = fileSearch Like "Test####[.]csv"
TextBox1.Text = FileNameMatch
End Sub

Upvotes: 1

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