IMAQdx Snap Example in VB.NET

[Larry.C]

Overview

Ever wanted to use the IMAQdx drivers with VB .NET and perform a snap image acquisition? Well you have come to the right place! It has been a long time waiting for an update to the legacy ActiveX method so I created my own. Enjoy!

Description

This VB .NET code implements a snap on a USB camera using the IMAQdx drivers. The code was written for Visual Studio 2010 with additional Measurement Studio plugin. Any USB camera can run this code and perform a snap in Visual Studio.

Steps to Implement or Execute Code

1. Open the Visual Studio 2010 project located in the zip file attached.
2. Ignore the warning asking to use a newer version of .NET drivers and press cancel:
   • 
3. While open you can simply run the code by pressing the run arrow in your toolbar.
4. The code should compile and search for available cameras.
5. Select the camera entry you want to use and press start
6. An image should be acquired by the camera and displayed in the central image viewer.
7. Pressing quit exits the application

Requirements

Software

Visual Studio 2010

Measurement Studio 2010

IMAQdx 4.0

Hardware

USB Camera

VB Snippet

Imports System.Collections.Generic Imports System.ComponentModel Imports System.Data Imports System.Drawing Imports System.Text Imports System.Windows.Forms Imports NationalInstruments.Vision Imports NationalInstruments.Vision.Acquisition.Imaqdx Namespace Snap     Partial Public Class Form1         Inherits Form         Private _session As ImaqdxSession         Public Sub New()             InitializeComponent()             startButton.Enabled = True             ' Enumerate cameras and populate control             Dim cameraList As ImaqdxCameraInformation() = ImaqdxSystem.GetCameraInformation(True)             If cameraList.Length > 0 Then                 cameraComboBox.Items.Clear()                 For Each camInfo As ImaqdxCameraInformation In cameraList                     cameraComboBox.Items.Add(camInfo.Name)                 Next                 cameraComboBox.SelectedIndex = 0             End If             ' Create image and attach to image viewer             Dim image As New NationalInstruments.Vision.VisionImage()             Me.ImageViewer.Attach(image)         End Sub         Private Sub startButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles startButton.Click             ' Open camera             _session = New ImaqdxSession(cameraComboBox.Text)             ' Snap an image             _session.Snap(Me.ImageViewer.Image)             ' Close the camera             _session.Close()         End Sub         Private Sub quitButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles quitButton.Click             Me.Close()             Application.[Exit]()         End Sub         Private Sub InitializeComponent()             Me.cameraComboBox = New System.Windows.Forms.ComboBox()             Me.startButton = New System.Windows.Forms.Button()             Me.quitButton = New System.Windows.Forms.Button()             Me.ImageViewer = New NationalInstruments.Vision.WindowsForms.ImageViewer()             Me.SuspendLayout()             '             'cameraComboBox             '             Me.cameraComboBox.FormattingEnabled = True             Me.cameraComboBox.Location = New System.Drawing.Point(21, 457)             Me.cameraComboBox.Name = "cameraComboBox"             Me.cameraComboBox.Size = New System.Drawing.Size(115, 21)             Me.cameraComboBox.TabIndex = 6             Me.cameraComboBox.Text = "cam0"             '             'startButton             '             Me.startButton.Location = New System.Drawing.Point(206, 454)             Me.startButton.Name = "startButton"             Me.startButton.Size = New System.Drawing.Size(85, 25)             Me.startButton.TabIndex = 7             Me.startButton.Text = "Start"             Me.startButton.UseVisualStyleBackColor = True             '             'quitButton             '             Me.quitButton.Location = New System.Drawing.Point(559, 454)             Me.quitButton.Name = "quitButton"             Me.quitButton.Size = New System.Drawing.Size(82, 25)             Me.quitButton.TabIndex = 8             Me.quitButton.Text = "Quit"             Me.quitButton.UseVisualStyleBackColor = True             '             'ImageViewer             '             Me.ImageViewer.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle             Me.ImageViewer.Location = New System.Drawing.Point(28, 20)             Me.ImageViewer.Name = "ImageViewer"             Me.ImageViewer.Size = New System.Drawing.Size(612, 402)             Me.ImageViewer.TabIndex = 9             '             'Form1             '             Me.ClientSize = New System.Drawing.Size(667, 490)             Me.Controls.Add(Me.ImageViewer)             Me.Controls.Add(Me.quitButton)             Me.Controls.Add(Me.startButton)             Me.Controls.Add(Me.cameraComboBox)             Me.Name = "Form1"             Me.Text = "Test"             Me.ResumeLayout(False)         End Sub         Private WithEvents cameraComboBox As System.Windows.Forms.ComboBox         Private WithEvents startButton As System.Windows.Forms.Button         Private WithEvents quitButton As System.Windows.Forms.Button         Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load         End Sub         Friend WithEvents ImageViewer As NationalInstruments.Vision.WindowsForms.ImageViewer         Private Sub ImageViewer_RoiChanged_1(ByVal sender As System.Object, ByVal e As NationalInstruments.Vision.WindowsForms.ContoursChangedEventArgs) Handles ImageViewer.RoiChanged         End Sub     End Class End Namespace

[Larry.C]

BTW, I am no VB expert and have probably made a number of mistakes. Please feel free to let me know if there are any improvements I can make!

[CertifiNATEtion]

Hi Larry,

I tried to run this program in Visual Studio 2010 and 2012 on two systems but ran into the following error. I have VDM 2013 installed, any thoughts on what could be causing this? Also this might need some more testing on other systems.

Error

12

Reference required to assembly 'NationalInstruments.Common, Version=8.7.35.131, Culture=neutral, PublicKeyToken=18cbae0f9955702a' containing the implemented interface 'NationalInstruments.ISupportSynchronizationContext'. Add one to your project.

C:\Users\nletchfo\Downloads\imaqdx.net\IMAQdx VB.NET\Form1.vb

14

29

IMAQdx VB.NET

The error occurs at _Session = New ImaqdxSession(cameraComboBox.Text)

[Larry.C]

Hi Nathanael,

I remember seeing that error. Have you checked your visual studio compiler is using ".NET 4" and not ".NET 4 Client Profile"?

I seem to think this fixed the problem for me.

Let me know how you get on!

Kind Regards,

Larry

[Larry.C]

Also, wanted to make sure you have also ignored the error message when you initially open the project as shown in the description above. Visual studio tries to force you to use a newer library instead of the .NET 3.5 and asks you to update. Make sure to cancel this message.

[eMoss]

I have an issue with the load of of the image when running the snap example. When the start button is clicked, there is a good 6-8 second delay for the image to appear. I've repeated this on two machines and both were slow. Any suggestions?

I am using visual studio 2010 and have NI Vision Development 2014 (this also installs NI-IMAQdx)