对文件的简单加密解密（任意文件）

一，方法一，代码运行一次是加密，再次运行是解密，代码如下：

Sub 文件的加密解密()
   Dim stm As New ADODB.Stream
   Dim str As String, i As Long
   Dim arr() As Byte
   str = ThisWorkbook.Path & "\文件"
   With stm
      .Type = adTypeBinary
      .Open
      .LoadFromFile str
      arr = .Read
      .Close
      For i = 0 To UBound(arr)
         arr(i) = 255 - arr(i)
      Next i
      .Open
      .Write arr
      .SaveToFile str, adSaveCreateOverWrite
      .Close
   End With
   Set stm = Nothing
End Sub

二，方法二，于方法一大同小异，运行一次是加密，再次运行是解密，代码如下：

Sub 文件的加密解密()
   Dim stm As New ADODB.Stream
   Dim str As String, i As Long
   Dim arr() As Byte
   str = ThisWorkbook.Path & "\file"
   With stm
      .Type = adTypeBinary
      .Open
      .LoadFromFile str
      arr = .Read
      .Close
      For i = 0 To UBound(arr)
         arr(i) = arr(i) Xor 100
      Next i
      .Open
      .Write arr
      .SaveToFile str, adSaveCreateOverWrite
      .Close
   End With
   Set stm = Nothing
End Sub