How to ignorecase when using string.text.contains?

I'm not a vb.net programmer, but according to Microsoft, you can get the lowercase/uppercase value of the text using the string methods ToUpper() or ToLower(). You can then compare that with "my house is cold" or "MY HOUSE IS COLD".

Dim myhousestring As String = "MY HOUSE IS COLD"
If txt.Text.ToUpper.Contains(myhousestring) Then
    Messagebox.Show("Found it")
End If

According to Microsoft you can do case-insensitive searches in strings with IndexOf instead of Contains. So when the result of the IndexOf method returns a value greater than -1, it means the second string is a substring of the first one.

Dim myhousestring As String = "My house is cold"
If txt.Text.IndexOf(myhousestring, 0, StringComparison.CurrentCultureIgnoreCase) > -1 Then
    Messagebox.Show("Found it")
End If

You can also use other case-insensitive variants of StringComparison.