今天來看看如何在Spread ASP.NET中顯示數據庫的數據關系，如下所示：

為了設置層級數據顯示，首先需要創建一個數據集，用來表示數據關系，然后就是定義數據數據之間的關系，最后設置控件顯示出你想要的數據效果，在下面的例子中就會詳細的講到：

在這個例子中，將這個控件綁定到了一個數據集上面，這個數據集中包含了來自數據庫的多個表格，然后設置控件層級的顯示數據。

所用的代碼如下：

Imports System.Data.OleDb
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
      If IsPostBack Then Return 
      ' Call subroutines to set up data and format the Spread component 
      InitData()
      FormatSpread()
End Sub
  
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
      ' Call subroutines to set up data and format the Spread component 
      InitData()
      FormatSpread()
End Sub
  
Private Sub InitData()
        Dim con As New OleDbConnection() 
        Dim cmd As New OleDbCommand() 
        Dim da As New OleDbDataAdapter() 
        Dim ds As New DataSet() 
        Dim dt As DataTable 
  
con.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\Program Files\GrapeCity\Spread.WebForms\Samples\Files\databind.mdb" 
con.Open()
  
With cmd
.Connection = con
.CommandType = CommandType.TableDirect
.CommandText = "Categories"
End With
  
da.SelectCommand = cmd
da.Fill(ds, "Categories")
  
cmd.CommandText = "Products"
da.SelectCommand = cmd
da.Fill(ds, "Products")
  
cmd.CommandText = "Inventory Transactions"
da.SelectCommand = cmd
da.Fill(ds, "Inventory Transactions")
  
ds.Relations.Add("Root", ds.Tables("Categories").Columns("CategoryID"), ds.Tables("Products").Columns("CategoryID"))

ds.Relations.Add("Secondary", ds.Tables("Products").Columns("ProductID"), ds.Tables("Inventory Transactions").Columns("TransactionID")) 
  
FpSpread1.DataSource = ds
End Sub
  
Private Sub FormatSpread()
With FpSpread1.Sheets(0)
.ColumnHeader.Rows(0).Height = 30
.Columns(0).Visible = False
            .Columns(0).Width = 200 
End With
End Sub
  
Private Sub FpSpread1_ChildViewCreated(ByVal sender As Object, ByVal e As FarPoint.Web.Spread.ChildViewCreatedEventArgs) Handles FpSpread1.ChildViewCreated 
Dim dateType As New FarPoint.Web.Spread.DateTimeCellType()
  
If e.SheetView.RelationName = "Root" Then
With e.SheetView
.DataAutoCellTypes = False
.ColumnHeader.Rows(0).Height = 30
.Columns(0).Visible = False
.Columns(3).Visible = False
.Columns(4).Visible = False
.Columns(1).Width = 200
.Columns(2).Width = 185
.Columns(6).Width = 85
.Columns(7).Width = 80
.Columns(8).Width = 80
.Columns(5).CellType = New FarPoint.Web.Spread.CurrencyCellType()
.Columns(7.CellType) = New FarPoint.Web.Spread.CheckBoxCellType()
End With
Else
With e.SheetView
.DataAutoCellTypes = False
.DataAutoSizeColumns = False
.ColumnHeader.Rows(0).Height = 30
.Columns(0).Visible = False
.Columns(2).Visible = False
.Columns(3).Visible = False
.Columns(4).Visible = False
.Columns(7).Visible = False
.Columns(8).Visible = False
.Columns(9).Visible = False
.Columns(1).Width = 100
.Columns(6).Width = 80
.Columns(5).CellType = New FarPoint.Web.Spread.CurrencyCellType()
.Columns(1).CellType = dateType
'Add a total column
.ColumnCount = .ColumnCount + 1
.ColumnHeader.Cells(0, .ColumnCount - 1).Value = "Total" 
.Columns(.ColumnCount - 1).CellType = New FarPoint.Web.Spread.CellType.CurrencyCellType()
.Columns(.ColumnCount - 1).Formula = "F1*G1"
End With
End If