标题：表的转换
Dim dtb As New DataTableBuilder("Excel转置")
dtb.AddDef("型号", Gettype(String),15)
dtb.AddDef("规格", Gettype(String),15)
dtb.AddDef("材料", Gettype(String))
dtb.AddDef("用量", Gettype(Double))
dtb.Build()
MainTable= Tables("Excel转置")
For i As Integer = 0 To Tables("EXCEL表").count -1
If Tables("EXCEL表").rows(i)("型号") > "" '用IsNull好些
For ii As Integer = 2 To Tables("EXCEL表").cols.count -1
Dim lm As String = Tables("EXCEL表").cols(ii).name
If Tables("EXCEL表").rows(i).IsNull(lm) = False
Tables("EXCEL转置").addnew
Dim r As Row = Tables("EXCEL转置").current
r("型号") = Tables("EXCEL表").rows(i)("型号")
r("规格") = Tables("EXCEL表").rows(i)("规格")
r("材料") = lm
r("用量") = Tables("EXCEL表").rows(i)(lm)
End If
Next
End If
Next
谢谢mr725，代码可用。现在想改进一下，因为数据量大，每次转换时只转换新加入的数据，已有的数据不变。
如果每次转换的数据量大，将窗口按钮代码改成这样好一点。
Dim drs As List(Of DataRow) = DataTables("EXCEL表").Select("[型号] Is Not Null And [sys_标记] = False")
If drs.Count = 0 Then
MessageBox.Show("没有新数据!")
Return
Else
Tables("窗口1_Table1").StopRedraw
For Each dr As DataRow In drs
For Each dc As DataCol In DataTables("EXCEL表").DataCols
Select Case dc.Name
Case "型号","规格","sys_标记"
Case Else
If dr.IsNull(dc.Name) = False Then
Dim r As Row = Tables("表B").Addnew
r("型号") = dr("型号")
r("规格") = dr("规格")
r("材料") = dc.Name
r("用量") = dr(dc.Name)
End If
End Select
Next
dr("sys_标记") = True
Next
Tables("窗口1_Table1").ResumeRedraw
End If