谢谢老师指导。老师好，我有4条线的坐标（每条线都是有几个线段组成），我要计算这4条线的长度，并累加在一起计算总长度。您看如何写代码。我写了下面的代码结果不通，您看怎么改动。
Dim x1,y1 As Single
Dim drs As List(Of DataRow)
Dim coordinate As DataTable = DataTables("Preplot")'
Dim linenames,Str2HSE As List(Of String)
linenames= coordinate.GetValues("LineName")
For Each nm As String In linenames
Output.Show(nm)
Next
Dim iH As Integer
messagebox.show("ok")
For iH=0 To linenames.count-1
messagebox.show("linenames.count=" & linenames.count)
drs=DataTables("Preplot").Select("LineName= '& linenames & '")
For Each dr As DataRow In drs
x1= dr("X")
y1= dr("Y")
messagebox.show("x1= "& x1 & "y1= "& y1)
Next
Return
Next
name x y
301
7359.6
79080.5
301
7270.0
79081.9
301
6257.1
79088.9
301
6147.7
79089.9
301
6082.1
79089.4
302
6754.3
78667.3
302
6315.5
78650.8
302
6215.9
78646.1
302
6123.0
78643.3
109
7077.6
79354.3
109
7367.4
79697.4
109
7435.5
79780.9
109
751650
79882.8
303
6763.1
78588.7
303
6074.7
78576.6
303
5976.5
78575.5
303
5828.1
78572.1
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Post By：2015/4/21 23:05:00 [显示全部帖子]
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