Table of Contents

User defined functions (VB.Net / netframework)

Note

This demo is available in your FlexCel installation at <FlexCel Install Folder>\samples\vb\VS2022\netframework\20.Reports\95.User Defined Functions and also at https:​//​github.​com/​tmssoftware/​TMS-​FlexCel.​NET-​demos/​tree/​master/​vb/​VS2022/​netframework/​Modules/​20.​Reports/​95.​User Defined Functions

Overview

Here we will see how to define a user function to calculate the number of orders by employee and shipper. This example is similar to the Pivot Tables example, but using only static normal cells.

Concepts

  • How to define user functions for non-standard needs. By the way: Try to define only as little user functions as you really need. User functions are on code, and a change on them means that you have to recompile the code.

  • We defined two ranges here, one horizontal and one vertical. The user defined function here will return a value for a couple of those values, allowing us to create a "static" pivot table.

Files

AssemblyInfo.vb

Imports System.Reflection
Imports System.Runtime.CompilerServices

'
' General Information about an assembly is controlled through the following 
' set of attributes. Change these attribute values to modify the information
' associated with an assembly.
'
<Assembly: AssemblyTitle("")>
<Assembly: AssemblyDescription("")>
<Assembly: AssemblyConfiguration("")>
<Assembly: AssemblyCompany("")>
<Assembly: AssemblyProduct("")>
<Assembly: AssemblyCopyright("(c) 2002 - 2014 TMS Software")>
<Assembly: AssemblyTrademark("")>
<Assembly: AssemblyCulture("")>

'
' Version information for an assembly consists of the following four values:
'
'      Major Version
'      Minor Version 
'      Build Number
'      Revision
'
' You can specify all the values or you can default the Revision and Build Numbers 
' by using the '*' as shown below:

<Assembly: AssemblyVersion("6.2.1.0")>

'
' In order to sign your assembly you must specify a key to use. Refer to the 
' Microsoft .NET Framework documentation for more information on assembly signing.
'
' Use the attributes below to control which key is used for signing. 
'
' Notes: 
'   (*) If no key is specified, the assembly is not signed.
'   (*) KeyName refers to a key that has been installed in the Crypto Service
'       Provider (CSP) on your machine. KeyFile refers to a file which contains
'       a key.
'   (*) If the KeyFile and the KeyName values are both specified, the 
'       following processing occurs:
'       (1) If the KeyName can be found in the CSP, that key is used.
'       (2) If the KeyName does not exist and the KeyFile does exist, the key 
'           in the KeyFile is installed into the CSP and used.
'   (*) In order to create a KeyFile, you can use the sn.exe (Strong Name) utility.
'       When specifying the KeyFile, the location of the KeyFile should be
'       relative to the project output directory which is
'       %Project Directory%\obj\<configuration>. For example, if your KeyFile is
'       located in the project directory, you would specify the AssemblyKeyFile 
'       attribute as [assembly: AssemblyKeyFile("..\\..\\mykey.snk")]
'   (*) Delay Signing is an advanced option - see the Microsoft .NET Framework
'       documentation for more information on this.
'
<Assembly: AssemblyDelaySign(False)>
<Assembly: AssemblyKeyFile("")>
<Assembly: AssemblyKeyName("")>

Form1.Designer.vb

Imports System.Collections
Imports System.ComponentModel
Imports System.IO
Imports System.Reflection
Imports FlexCel.Core
Imports FlexCel.XlsAdapter
Imports FlexCel.Report
Imports FlexCel.Demo.SharedData
Namespace UserDefinedFunctions
	Partial Public Class mainForm
		Inherits System.Windows.Forms.Form

		''' <summary>
		''' Required designer variable.
		''' </summary>
		Private components As System.ComponentModel.Container = Nothing

		''' <summary>
		''' Clean up any resources being used.
		''' </summary>
		Protected Overrides Sub Dispose(ByVal disposing As Boolean)
			If disposing Then
				If components IsNot Nothing Then
					components.Dispose()
				End If
			End If
			MyBase.Dispose(disposing)
		End Sub

		#Region "Windows Form Designer generated code"
		''' <summary>
		''' Required method for Designer support - do not modify
		''' the contents of this method with the code editor.
		''' </summary>
		Private Sub InitializeComponent()
			Me.button1 = New System.Windows.Forms.Button()
			Me.saveFileDialog1 = New System.Windows.Forms.SaveFileDialog()
			Me.label1 = New System.Windows.Forms.Label()
			Me.btnCancel = New System.Windows.Forms.Button()
			Me.SuspendLayout()
			' 
			' button1
			' 
			Me.button1.Anchor = (CType((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles))
			Me.button1.BackColor = System.Drawing.Color.Green
			Me.button1.ForeColor = System.Drawing.Color.White
			Me.button1.Location = New System.Drawing.Point(152, 88)
			Me.button1.Name = "button1"
			Me.button1.Size = New System.Drawing.Size(112, 23)
			Me.button1.TabIndex = 0
			Me.button1.Text = "GO!"
			Me.button1.UseVisualStyleBackColor = False
'			Me.button1.Click += New System.EventHandler(Me.button1_Click)
			' 
			' saveFileDialog1
			' 
			Me.saveFileDialog1.Filter = "Excel Files|*.xls;*.xlsx;*.xlsm|Excel 97/2003|*.xls|Excel 2007|*.xlsx;*.xlsm|All files|*.*"
			Me.saveFileDialog1.RestoreDirectory = True
			' 
			' label1
			' 
			Me.label1.Location = New System.Drawing.Point(24, 24)
			Me.label1.Name = "label1"
			Me.label1.Size = New System.Drawing.Size(288, 24)
			Me.label1.TabIndex = 2
			Me.label1.Text = "A Crosstab report using an user defined function."
			' 
			' btnCancel
			' 
			Me.btnCancel.Anchor = (CType((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles))
			Me.btnCancel.BackColor = System.Drawing.Color.FromArgb((CInt((CByte(192)))), (CInt((CByte(0)))), (CInt((CByte(0)))))
			Me.btnCancel.DialogResult = System.Windows.Forms.DialogResult.Cancel
			Me.btnCancel.ForeColor = System.Drawing.Color.White
			Me.btnCancel.Location = New System.Drawing.Point(272, 88)
			Me.btnCancel.Name = "btnCancel"
			Me.btnCancel.Size = New System.Drawing.Size(112, 23)
			Me.btnCancel.TabIndex = 3
			Me.btnCancel.Text = "Cancel"
			Me.btnCancel.UseVisualStyleBackColor = False
'			Me.btnCancel.Click += New System.EventHandler(Me.btnCancel_Click)
			' 
			' mainForm
			' 
			Me.AutoScaleDimensions = New System.Drawing.SizeF(6F, 13F)
			Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
			Me.ClientSize = New System.Drawing.Size(416, 133)
			Me.Controls.Add(Me.btnCancel)
			Me.Controls.Add(Me.label1)
			Me.Controls.Add(Me.button1)
			Me.Name = "mainForm"
			Me.Text = "User defined functions"
			Me.ResumeLayout(False)

		End Sub
		#End Region

		Private WithEvents button1 As System.Windows.Forms.Button
		Private saveFileDialog1 As System.Windows.Forms.SaveFileDialog
		Private label1 As System.Windows.Forms.Label
		Private WithEvents btnCancel As System.Windows.Forms.Button
	End Class
End Namespace

Form1.vb

Imports System.Collections
Imports System.ComponentModel
Imports System.IO
Imports System.Reflection
Imports FlexCel.Core
Imports FlexCel.XlsAdapter
Imports FlexCel.Report
Imports FlexCel.Demo.SharedData


Namespace UserDefinedFunctions
	Partial Public Class mainForm
		Inherits System.Windows.Forms.Form

		Public Sub New()
			InitializeComponent()
		End Sub

		Private Sub button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles button1.Click
			AutoRun()
		End Sub

		Public Sub AutoRun()
			Using ordersReport As FlexCelReport = SharedData.CreateReport()
				ordersReport.SetValue("Date", Date.Now)
				ordersReport.SetUserFunction("Orders", New OrdersImp(SharedData.GetOrders()))

				Dim DataPath As String = Path.Combine(Path.Combine(Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location), ".."), "..") & Path.DirectorySeparatorChar

				If saveFileDialog1.ShowDialog() = System.Windows.Forms.DialogResult.OK Then
					ordersReport.Run(DataPath & "User Defined Functions.template.xls", saveFileDialog1.FileName)

					If MessageBox.Show("Do you want to open the generated file?", "Confirm", MessageBoxButtons.YesNo) = System.Windows.Forms.DialogResult.Yes Then
						Process.Start(saveFileDialog1.FileName)
					End If
				End If
			End Using
		End Sub


		Private Sub btnCancel_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnCancel.Click
			Close()
		End Sub

	End Class

	#Region "Orders Implementation"
	Friend Class OrdersImp
		Inherits TFlexCelUserFunction

		Private OrdersDv As DataView

		Public Sub New(ByVal OrdersTable As DataTable)
			OrdersDv = New DataView(OrdersTable, String.Empty, "EmployeeID,ShipVia", DataViewRowState.CurrentRows)
		End Sub
		Public Overrides Function Evaluate(ByVal parameters() As Object) As Object
			If parameters Is Nothing OrElse parameters.Length <> 2 Then
				Throw New ArgumentException("Bad parameter count in call to Orders() user-defined function")
			End If

			Dim Count As Integer = OrdersDv.FindRows(parameters).Length
			If Count > 0 Then
				Return Count
			Else
				Return Nothing
			End If
		End Function
	End Class
	#End Region

End Namespace

Program.vb

Namespace UserDefinedFunctions
	Friend NotInheritable Class Program

		Private Sub New()
		End Sub

		''' <summary>
		''' The main entry point for the application.
		''' </summary>
		<STAThread> _
		Shared Sub Main()
			Application.EnableVisualStyles()
			Application.SetCompatibleTextRenderingDefault(False)
			Application.Run(New mainForm())
		End Sub
	End Class
End Namespace