對象引用未設置爲對象的實例 - vb.net

Question

首先有一點背景信息：此應用程序的目的是捕獲圖像並將它們自動保存到網絡目錄中，該網絡目錄將被創建或使用文本框。此代碼可以在我的電腦上工作（Windows 7 Home 64位）。我一直在使用它的Microsoft Visual Basic快遞2010年

但是.....試圖在Windows運行應用程序10平板電腦時創建的，我得到了如下錯誤：

在形式負載：

An error occurred while capturing the image. The video capture will now be terminated. 

Object reference not set to an instance of an object. 

在button2_Click事件：

Object reference not set to an instance of an object. 

下面是代碼的全部。

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 

正如你所朝的末見Form2.vb，我一直在嘗試包裹imgCapture.Image.Save(SaveDir & OrderNumber.Text & "\" & CStr(imgIndex) & ".jpg")因爲我懷疑這是pictureBox對象的某種問題， try catch塊確實捕捉到異常，但我仍然不知道問題是什麼，爲什麼它發生在平板電腦上而不是PC上，或者如何解決它。

我發現了類似的問題，但都沒有提供我可以使用的解決方案。

Answer 1

由於您使用的圖書館EasyWebCam過時且與Win10不兼容，因此我建議您切換圖書館。其他的選擇了：

DirectX.Capture
Windows.Media.Capture