Dim str As String
str = "天天天天你你你你天天天天"
Dim iSt As Integer, iEd As Integer
Dim iCount As Integer
iCount = 4
iSt = 0
iEd = iSt + iCount
While iEd < str.Length
Console.WriteLine(str.Substring(iSt, iCount))
iSt = iEd
iEd = iSt + iCount
End While
Console.WriteLine(str.Substring(iSt, iCount - (iEd - str.Length)))