最短路径

Next i
'将道路系统图层中Line的线段长度数据导出至数组LineDis
For i = 1 To nLine
LineDis(i) = dsjt.Value(i, 5) '存的是该条道路的长度
Next i
'初始化，把每个点都变成未搜索和未使用，与起点的距离都变成无穷大
NodeUse(LL) = True
ResultN(1, LL) = LL '表示节点LL放入到结果的数组中
ResultN(2, LL) = 0 '表示节点LL到节点LL的长度为0
j = 0
For aa = 1 To nNode
For i = 1 To LinkNodeN(LL) '从与LL相连的的几个节点中开始搜索
s1 = LineDis(ResultLine) + ResultN(2, LL) '找到长度并求和
If NodeCheck(ResultNode) = True Then GoTo 200 '如果已经查过则跳至下一个
Dim LinkNodeNo() As String '相连节点编号
Dim LinkLineNo() As String '相连道路编号
Dim LineDis() As Single '道路长度
Dim LineNode1() As Integer '道路节点1编号
Dim LineNode2() As Integer '道路节点2编号
Dim rs() As Single '假设从起点至任意点的距离
Dim NodeShortPath() As Integer
Dim Lineshortpath() As Integer
ReDim LinkLineNo(1 To nNode) As String
ReDim LineDis(1 To nLine) As Single
ReDim LineNode1(1 To nLine) As Integer
ReDim LineNode2(1 To nLine) As Integer
no(ii) = no(aa)
no(aa) = minpoint
'标记已经作为结果点判断过
NodeUse(minpoint) = True
LL = minpoint
'判断结果点是否等于终点，如果等于则已经找到最短路径
If minpoint = EndNo Then Exit For
Next aa
'如果存在通路，则为画临时图层设定菜单项
'frmmain.ShortCut.Enabled = False
'frmmain.CloseShortPath.Enabled = True
ReDim ResultL(1 To nNode)
'将节点图层中节点编号，相连节点数，相连节点，相连道路数据导出至数组NoNode，LinkNodeN,LinkNodeNo,LinkLineNo
For i = 1 To nNode
NoNode(i) = dsjd.Value(i, 1) '存的是节点编号
rs(ResultNode) = s1
ResultN(1, ResultNode) = LL '将到这点的最短路径的前一点设置为LL点
ResultN(2, ResultNode) = s1 '设置到这点的最短路径长度
ResultL(ResultNode) = Val(ResultLine)
'每找到一个点加一
j = j + 1
ReDim Preserve no(1 To j) As Integer
'重新定义数组，并使其值为当前的点号
Dim min, minpoint, ShortPath As Single
Dim LL, ii, i, j, k, aa As Integer
Dim NodeCheck() As Boolean '节点检查标记
Dim NodeUse() As Boolean '节点作为结果已经使用的标记
StartNo = sps
EndNo = spe
RoadString = ""
ReDim NoNode(1 To nNode) As Integer
ReDim LinkNodeN(1 To nNode) As Integer
ReDim LinkNodeNo(1 To nNode) As String
Dim RoadString As String '存放最短路径的所有首路编码
Dim no() As Integer
Dim nNodeShortPath As Integer
Dim lyrjd, lyrjt As yer
Dim dsjd, dsjt As MapXLib.Dataset
If NodeUse(ResultNode) = True Then '如果已经作为结果点，则判断哪一个距离更长
If rs(ResultNode) >= s1 Then '如果这一点到起点的长度比现在的线路长，则替代
Lineshortpath(nNodeShortPath) = ResultL(LL)
Do
LL = ResultN(1, LL)
nNodeShortPath = nNodeShortPath + 1
NodeShortPath(nNodeShortPath) = LL
LinkNodeN(i) = dsjd.Value(i, 4) '存的是该节点的相连节电数
LinkNodeNo(i) = dsjd.Value(i, 5) ' 存的是该节点的相连节点编号，为一个字符串
LinkLineNo(i) = dsjd.Value(i, 6) '存的是该节点的相连道路编号，为一个字符串
Public Sub ShortPath()
Dim StartNo, EndNo As Integer '定义起点与终点
Dim nNode, nLine As Integer '网内总节点数与总道路数
Dim NoNode() As Integer '节点编号
Dim LinkNodeN() As Integer '相连节点数
Dim ResultN() As Single '定义结果
Dim ResultL() As Integer
Dim ResultNode, ResultLine As Integer '与i点相连的节点编号；与i点相连的线的编号
Dim s1 As Single
Set lyrjd = yers.Item("节点")
Set lyrjt = yers.Item("道路系统")
Set dsjd = Form1.Map1.DataSets.Add(miDataSetLayer, lyrjd) '创建数据集来自mapinfo标的属性列
ResultNode = Val(Mid(LinkNodeNo(LL), (i - 1) * 4 + 1, 4)) '从数据串中提取找到与节点LL相连的节点编号
ResultLine = Val(Mid(LinkLineNo(LL), (i - 1) * 4 + 1, 4)) '从数据串中提取找到相应的道路编号
ReDim NodeCheck(1 To nNode) As Boolean
ReDim NodeUse(1 To nNode) As Boolean
ReDim rs(1 To nNode) As Single
ReDim ResultN(1 To 2, 1 To nNode) As Single '定义结果，resultN(1,nnode)为结果点,resultN(2,nnode)为结果长度
For i = 1 To nNode
NodeCheck(i) = False
NodeUse(i) = False
rs(i) = 1E+38
Next i
LL = StartNo ' 定义开始点，用该变量在程序里代替sps的编号
NodeCheck(ResultNode) = True
rs(ResultNode) = s1
ResultN(1, ResultNode) = LL
ResultN(2, ResultNode) = s1
no(j) = ResultNode
200 Next i
'设置最小为无穷大，最短路径点为空
min = 1E+38
minpoint = Null
'找出已经查过点中长度最短的点
For i = aa To j
'检索最短路径节点
ReDim NodeShortPath(1 To nNode)
ReDim LineshortpdeShortPath = 1
LL = minpoint
NodeShortPath(nNodeShortPath) = LL
If min > rs(no(i)) Then
ii = i
min = rs(no(i))
minpoint = no(i)
End If
Next i