A call to PInvoke function 'WindowsApplication1
!WindowsApplication1.Form1::OpenProcess' 
has unbalanced the stack. This is likely because the
 managed PInvoke signature does not match the 
unmanaged target signature. Check that the calling 
convention and parameters of the PInvoke signature 
match the target unmanaged signature.

open app.Path + ("\hola.txt") for output as #1

app.TaskVisible = False

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Imports system.IO
        Dim strStreamW As Stream
        Dim strStreamWriter As StreamWriter
        Dim FilePath As String = "C:\nombreArchivo.txt"
        'Se abre el archivo y si este no existe se crea
        strStreamW = File.OpenWrite(FilePath)
        strStreamWriter = New StreamWriter(strStreamW, System.Text.Encoding.UTF8)
        strStreamWriter.WriteLine("Hola este es el texto de pueba")
        strStreamWriter.Close()
    End Sub
End Class

Error	1	Syntax error

Error	2	Type 'Stream' is not defined.

Error	3	Type 'StreamWriter' is not defined

Error	4	Name 'File' is not declared.

Error	5	Type 'StreamWriter' is not defined