Exit macro when no file is selected for open

I need to exit the macro when if the user is not selecting any file and clicks "Cancel" in the file picker dialog box. Below is my exisintg code

Sub OpenFile()

With Application.FileDialog(msoFileDialogFilePicker)
    .InitialFileName = ThisWorkbook.Path
    
    If .Show <> -1 Then Exit Sub
    strFile = .SelectedItems(1)
    Sheets("Sheet1").Cells.ClearContents
    Open strFile For Input As #1
    i = 1
    Do While Not EOF(1) ' Loop until end of file.
        Line Input #1, Text
        Sheets("Sheet1").Range("A" & i) = Text
        i = i + 1
    Loop
    Close #1
End With

End Sub

Sub Opertion()

OpenFile

End Sub()