compare 2 string to get result different - asp.net

Question

i am doing a method that able to return me what is the different between data before and data after
Dim dataBefore As String = "Name:Alice,Age:30,Sex:Male"
Dim dataAfter As String = "Name:Alice,Age:20,Sex:Female"
mtdCompare2String(dataBefore,dataAfter)
Public Shared Function mtdCompare2String(ByVal sBefore As String, ByVal sAfter As String) As String
//what i try to do before, supposing my loop should start over here but i failed,
//so i just removed the loop, i need someone to correct me =(
Dim intBefore As Integer = sBefore.IndexOf(",")
Dim intAfter As Integer = sAfter.IndexOf(",")
Dim sBefore As String = sBefore.SubString(0,intBefore)
Dim sAfter As String = sAfter.SubString(sAfter.IndexOf(":"),intAfter)
Dim sb As StringBuilder
sb.append(sBefore,sAfter)
return sb.toString
End Function
Expected Result
Age:30>20,Sex:Male>Female

Answer 1

Something like this should work:
Public Shared Function mtdCompare2String(ByVal sBefore As String, ByVal sAfter As String) As String
'what i try to do before, supposing my loop should start over here but i failed,
'so i just removed the loop, i need someone to correct me =(
Dim Before() As String = sBefore.Split(",")
Dim After() As String = sAfter.Split(",")
Dim ReturnString As String = ""
For I = 0 To Before.Length - 1
Dim TempBefore As String = Before(I).Split(":")(1)
Dim TempAfter As String = After(I).Split(":")(1)
If TempBefore <> TempAfter Then
ReturnString += Before(I).Split(":")(0) + ":" + TempBefore + ">" + TempAfter + ","
End If
Next
Return ReturnString.Substring(0, ReturnString.Length - 1)
End Function