Dim instance As StdFunc = New StdFunc()
Dim filePathName As String	'ファイルのフルパス
Dim returnValue As String	'成功:文字列  失敗:Nothing

returnValue = instance.FileRead(filePathName)	'エンコードを指定しない場合はUTF-8として読み込み

Dim instance As StdFunc = New StdFunc()
Dim filePathName As String	'ファイルのフルパス
Dim encodeStr As String		'エンコードを表す文字列　"utf8" "shift_jis" "iso-2022-jp" "euc-jp"
Dim returnValue As String	'成功:文字列  失敗:Nothing

returnValue = instance.FileRead(filePathName, encodeStr)

Dim instance As StdFunc = New StdFunc()
Dim filePathName As String	'ファイルのフルパス
Dim encode As System.Text.Encoding	'エンコード
Dim returnValue As String	'成功:文字列  失敗:Nothing

returnValue = instance.FileRead(filePathName, encode)

'StdFuncクラス FileReadメソッド

Imports System
Imports System.Windows.Forms
Imports Microsoft.VisualBasic

Public Class AddIn

	Private stdf As StdFunc

	Public Sub New()
		stdf = New StdFunc()
	End Sub

	Public Sub AddIn_Start()
		Dim fname As String = "D:\tmp\input.txt"
		Dim result As String = stdf.FileRead(fname)
		If result Is Nothing Then
			MessageBox.Show("読み込みに失敗しました")
		Else
			MessageBox.Show("読み込んだ文字列：" & ControlChars.CrLf & result)
		End If
	End Sub

End Class

'StdFuncクラス FileReadメソッド

Imports System
Imports System.Windows.Forms
Imports Microsoft.VisualBasic

Public Class AddIn

	Private stdf As StdFunc

	Public Sub New()
		stdf = New StdFunc()
	End Sub

	Public Sub AddIn_Start()
		Dim fname As String = "D:\tmp\input.txt"
		Dim result As String = stdf.FileRead(fname, "euc-jp")
		If result Is Nothing Then
			MessageBox.Show("読み込みに失敗しました")
		Else
			MessageBox.Show("読み込んだ文字列：" & ControlChars.CrLf & result)
		End If
	End Sub

End Class

'StdFuncクラス FileReadメソッド

Imports System
Imports System.Windows.Forms
Imports Microsoft.VisualBasic

Public Class AddIn

	Private stdf As StdFunc

	Public Sub New()
		stdf = New StdFunc()
	End Sub

	Public Sub AddIn_Start()
		Dim fname As String = "D:\tmp\input.txt"
		Dim result As String = stdf.FileRead(fname, System.Text.Encoding.GetEncoding(932))
		If result Is Nothing Then
			MessageBox.Show("読み込みに失敗しました")
		Else
			MessageBox.Show("読み込んだ文字列：" & ControlChars.CrLf & result)
		End If
	End Sub

End Class