Dim myEncoder As New System.Text.UTF8Encoding
Dim Key() As Byte = myEncoder.GetBytes("testappSecret") '
Dim XML() As Byte = myEncoder.GetBytes("1546084445901")
Dim myHMACSHA256 As New System.Security.Cryptography.HMACSHA256(Key)
Dim HashCode As Byte() = myHMACSHA256.ComputeHash(XML)
Dim result = Convert.ToBase64String(HashCode)
result的值和你红色的一样