How to count instances of string found within files - excel

Question

I am using this code to search within all relevant files in a folder.
How can I add the amount of times the string is found in each file so I can return that number? If it matters, I do know that the string I am searching will only be found once on each line of text.
I have tried a bunch of random things but I get only "1" returned, which I know is false.
Sub StringExistsInFile()
Dim theString As Variant
Dim path As String
Dim StrFile As String
Dim fso As New FileSystemObject
Dim file As TextStream
Dim line As String
theString = Userform1.TextBox1.Text
path = "P:\prg\"
StrFile = Dir(path & "*.dp")
Do While StrFile <> ""
Set file = fso.OpenTextFile(path & StrFile)
Do While Not file.AtEndOfLine
line = file.ReadLine
If InStr(1, line, theString, vbTextCompare) > 0 Then
Userform1.ListBox1.AddItem (StrFile)
Exit Do
End If
Loop
file.Close
Set file = Nothing
Set fso = Nothing
StrFile = Dir()
Loop
End Sub

Answer 1

Your code stopped at the first empty line within each file as you looped until AtEndOfLine.
Please try this:
Sub StringExistsInFile()
Dim theString As Variant
Dim path As String
Dim StrFile As String
Dim fso As New FileSystemObject
Dim file As TextStream
Dim line As String
Dim amount As Long
Dim theResult as String
theString = Userform1.TextBox1.Text
path = "P:\prg\"
StrFile = Dir(path & "*.dp")
Do While StrFile <> ""
Set file = fso.OpenTextFile(path & StrFile)
amount = 0
Do While Not file.AtEndOfStream
line = file.ReadLine
If InStr(1, line, theString, vbTextCompare) > 0 Then
amount = amount + 1
End If
Loop
If amount > 0 Then
Userform1.ListBox1.AddItem (StrFile & ": " & theString & " = " & amount)
End If
file.Close
Set file = Nothing
Set fso = Nothing
StrFile = Dir()
Loop
End Sub