Dim dt As New DataTable
If userZip <> "" And userRadius <> "" Then
userzipLat = getLatitude(userZip)
userzipLong = getLongitude(userZip)
dt = SQL2DataTable(DistLatLon_sql)
'the following code is highlighted because it demonstrates how to define a new column for a 'DataTable with a defined data type. When a column is added and not defined ...it is assumed as 'a string which cannot be sorted properly if your data is not really strings.
Dim colDecimalDistance As DataColumn = New DataColumn("distance")
colDecimalDistance.DataType = System.Type.GetType("System.Decimal")
dt.Columns.Add(colDecimalDistance)
If dt.Rows.Count > 0 Then
For Each rw As DataRow In dt.Rows
distLat = rw.Item("Latitude")
distLong = rw.Item("Longitude")
rw.Item("distance") = Math.Round(getDistance(userzipLat, userzipLong, distLat, distLong), 1)
Next
End If
End If
'We can sort a DataTable by adding it to a view and then using the view class's Sort 'method. The 'ToTable method of the DataView class let's us easily return the view to a DataTable.
'Note* This is not the only way to sort columns in DataTables...but simple
Dim view As New DataView(dt)
view.Sort = "distance ASC"
'now reset dt to the distance ordered datatable
dt = view.ToTable()
Tags: Sorting
