First a little background information: The purpose of this application is to capture images and save them automatically to a network directory that will be either created or appended using the input of the text box. This code DOES work on my computer (windows 7 home 64 bit). I've created it using microsoft visual basic express 2010.
However..... when attempting to run the application on a windows 10 tablet, I get the follow errors:
On form load:
An error occurred while capturing the image. The video capture will now be terminated.
Object reference not set to an instance of an object.
On button2_Click Event:
Object reference not set to an instance of an object.
Below is the entirety of the code.
Form2.vb
Public Class Form2
Public scanIsSet As Boolean
Private webcam As WebCam
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
webcam = New WebCam()
webcam.InitializeWebCam(imgVideo)
webcam.Start()
scanIsSet = False
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim CFGfile As String
Dim SaveDir As String
Dim imgIndex As Integer
Dim existingImages() As String
SaveDir = "C:\somepath\"
'save image to directory with index number
Try
imgCapture.Image.Save(SaveDir & OrderNumber.Text & "\" & CStr(imgIndex) & ".jpg")
Catch ex As Exception
MsgBox("error while accessing object imgCapture" & ex.Message)
End Try
imgIndex = imgIndex + 1
Else
Beep()
MsgBox("Please scan or type in order number first")
End If
End Sub
End Class
WebCam.vb
Imports System
Imports System.IO
Imports System.Linq
Imports System.Text
Imports WebCam_Capture
Imports System.Collections.Generic
Imports ZXing
Imports ZXing.OneD
'Design by Pongsakorn Poosankam
Class WebCam
Public scanz As Boolean
Public Sub setScan(ByVal x As Boolean)
scanz = x
End Sub
Private webcam As WebCamCapture
Private _FrameImage As System.Windows.Forms.PictureBox
Private FrameNumber As Integer = 30
Public Sub InitializeWebCam(ByRef ImageControl As System.Windows.Forms.PictureBox)
webcam = New WebCamCapture()
webcam.FrameNumber = CULng((0))
webcam.TimeToCapture_milliseconds = FrameNumber
AddHandler webcam.ImageCaptured, AddressOf webcam_ImageCaptured
_FrameImage = ImageControl
End Sub
Private Sub webcam_ImageCaptured(ByVal source As Object, ByVal e As WebcamEventArgs)
_FrameImage.Image = e.WebCamImage
If scanz = True Then
Dim BCreader As New ZXing.BarcodeReader
'BCreader.Options.TryHarder = True
Try
Dim resu As Result = BCreader.Decode(e.WebCamImage)
Form2.OrderNumber.Text = resu.Text
setScan(False)
Form2.Label2.Text = ""
Beep()
Catch ex As Exception
'do nothing
End Try
End If
End Sub
Public Sub Start()
webcam.TimeToCapture_milliseconds = FrameNumber
webcam.Start(0)
End Sub
Public Sub [Stop]()
webcam.[Stop]()
End Sub
Public Sub [Continue]()
' change the capture time frame
webcam.TimeToCapture_milliseconds = FrameNumber
' resume the video capture from the stop
webcam.Start(Me.webcam.FrameNumber)
End Sub
Public Sub ResolutionSetting()
webcam.Config()
End Sub
Public Sub AdvanceSetting()
webcam.Config2()
End Sub
End Class
As you can see toward the end of Form2.vb, I've wrapped imgCapture.Image.Save(SaveDir & OrderNumber.Text & "\" & CStr(imgIndex) & ".jpg") in a Try-Catch block because I suspect it's some sort of problems with the pictureBox objects. The try catch block does indeed catch the exception, but I still have no idea what the problem is, why it happens on the tablet and not the PC, or how to fix it.
I've found similar questions, but none with a solution I can make use of.
