Table of Contents

Using Linq as datasource (VB.Net / netframework)

Note

This demo is available in your FlexCel installation at <FlexCel Install Folder>\samples\vb\VS2022\netframework\20.Reports\22.Linq and also at https:​//​github.​com/​tmssoftware/​TMS-​FlexCel.​NET-​demos/​tree/​master/​vb/​VS2022/​netframework/​Modules/​20.​Reports/​22.​Linq

Overview

THIS DEMO NEEDS .NET 3.5 OR NEWER.

Most of the demos here use datasets as datasources. This is just for convenience, because Linq is not supported in .NET 2.0 and so if we used Linq those demos wouldn't work for everybody, and also because the focus is in the Excel templates, not so much in the data layer. But you can use any IQueryable<T> collection as a datasource in a FlexCel report, and this is what we will show here.

Concepts

  • How to run a report from a List<> of objects.

  • When using IQueryable<T> as datasource, you can use any public property of T in the report. So if type T has a public property "LastName", you can access it with <#dt.LastName>.

  • Master detail with implicit relationships. When a public property of a collection of objects is other collection of objects, the property is considered as a detail of the main collection. In this example "Elements" is a property of "Categories", and so there is an implicit relationship between them.

  • Master detail with explicit relationships. While when using LINQ you will normally use implicit relationships, you can also relate any two collections of objects with a relationship, as you could with datasets. In this example, "ElementName" is explicitly related to "Elements" with a call to FlexCelReport.AddRelationship.

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

		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
		''' <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"
			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(272, 24)
			Me.label1.TabIndex = 2
			Me.label1.Text = "Press ""GO"" to create a report from a List<> of objects."
			' 
			' 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 = "Linq Reports"
			Me.ResumeLayout(False)

		End Sub
		#End Region
	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


Namespace Linq
	''' <summary>
	''' Summary description for Form1.
	''' </summary>
	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 report As New FlexCelReport(True)
				LoadTables(report)

				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
					report.Run(DataPath & "Linq.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 LoadTables(ByVal report As FlexCelReport)
			Dim Categories As New List(Of Categories)()
			Dim Animals As New Categories("Animals")
			Animals.Elements.Add(New Elements(1, "Penguin"))
			Animals.Elements.Add(New Elements(2, "Cat"))
			Animals.Elements.Add(New Elements(3, "Unicorn"))
			Categories.Add(Animals)

			Dim Flowers As New Categories("Flowers")
			Flowers.Elements.Add(New Elements(4, "Daisy"))
			Flowers.Elements.Add(New Elements(5, "Rose"))
			Flowers.Elements.Add(New Elements(6, "Orchid"))
			Categories.Add(Flowers)

			report.AddTable("Categories", Categories)
			'We don't need to call AddTable for elements since it is already added when we add Categories.


			Dim ElementNames As New List(Of ElementName)()
			ElementNames.Add(New ElementName(1, "Linus"))
			ElementNames.Add(New ElementName(1, "Gerard"))
			ElementNames.Add(New ElementName(2, "Rover"))
			ElementNames.Add(New ElementName(3, "Mike"))
			ElementNames.Add(New ElementName(5, "Rosalyn"))
			ElementNames.Add(New ElementName(5, "Monica"))
			ElementNames.Add(New ElementName(6, "Lisa"))

			report.AddTable("ElementName", ElementNames)
			'ElementName doesn't have an intrinsic relationship with categories, so we will have to manually add a relationship.
			'Non intrinsic relationships should be rare, but we do it here to show how it can be done.
			report.AddRelationship("Elements", "ElementName", "ElementID", "ElementID")
		End Sub

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

	Public Class Categories
		'Public properties can be used in reports.
		Private privateName As String
		Public Property Name() As String
			Get
				Return privateName
			End Get
			Private Set(ByVal value As String)
				privateName = value
			End Set
		End Property

		'Elements is in master-detail relationship with this element, even when we don't explicitly add a relationship. 
		'Relationship is inferred because Elements is a property of this object
		Private privateElements As List(Of Elements)
		Public Property Elements() As List(Of Elements)
			Get
				Return privateElements
			End Get
			Private Set(ByVal value As List(Of Elements))
				privateElements = value
			End Set
		End Property

		Public Sub New(ByVal name As String)
			Me.Name = name
			Elements = New List(Of Elements)()
		End Sub

	End Class

	Public Class Elements
		'We will relate this property with the table of colors by adding a relationship.
		Private privateElementID As Integer
		Public Property ElementID() As Integer
			Get
				Return privateElementID
			End Get
			Private Set(ByVal value As Integer)
				privateElementID = value
			End Set
		End Property

		Private privateName As String
		Public Property Name() As String
			Get
				Return privateName
			End Get
			Private Set(ByVal value As String)
				privateName = value
			End Set
		End Property


		Public Sub New(ByVal elementID As Integer, ByVal name As String)
			Me.Name = name
			Me.ElementID = elementID
		End Sub

	End Class

	Public Class ElementName
		Private privateElementID As Integer
		Public Property ElementID() As Integer
			Get
				Return privateElementID
			End Get
			Private Set(ByVal value As Integer)
				privateElementID = value
			End Set
		End Property
		Private privateName As String
		Public Property Name() As String
			Get
				Return privateName
			End Get
			Private Set(ByVal value As String)
				privateName = value
			End Set
		End Property

		Public Sub New(ByVal elementID As Integer, ByVal name As String)
			Me.ElementID = elementID
			Me.Name = name
		End Sub
	End Class

End Namespace

Program.vb

Namespace Linq
	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