vb.net - NullReferenceException がキャッチされました

Question

vb.net 2008 と Sql 2008 を使用しており、画像をデータベースに保存する必要があります。最初にコードを実行したときは保存されていましたが、後で NullReferenceException がキャッチされたことに気付きました。オブジェクト参照がオブジェクト インスタンスに設定されていません。私はちょうど混乱している ！

以下のコード

Imports System.Data.SqlClient
Imports System.IO


Private Sub btnImage1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnImage1.Click
        'Code to load picture
        Dim OpenFileDialog1 As New OpenFileDialog
        OpenFileDialog1.Filter = "JPG|*.jpg|BITMAP|*.bmp|GIF|*.gif"
        OpenFileDialog1.ShowDialog()
        If OpenFileDialog1.FileName <> "" AndAlso IO.File.Exists(OpenFileDialog1.FileName) Then
            Dim Extention As String = New IO.FileInfo(OpenFileDialog1.FileName).Extension
            Select Case Extention.ToLower
                Case Is = ".jpg", Is = ".bmp", Is = ".gif"
                Case Else
                    MsgBox("Only JPG, BMP and GIF files are allowed. Thank you")
                    Exit Sub
            End Select
            Me.Pic1.Image = Image.FromFile(OpenFileDialog1.FileName)
        End If
    End Sub


'Code to save picture (I stepped into the code and the frmAllottee.Pic1 is there)
Public Sub Save_Picture()
        Dim sql_command As SqlCommand
        Dim mStream As MemoryStream = New MemoryStream()
        'Dim mstream As New MemoryStream()
        frmAllottee.Pic1.BackgroundImage.Save(mstream, frmAllottee.Pic1.BackgroundImage.RawFormat) - This line gives the error
        Dim arrImage() As Byte = mstream.GetBuffer()
        mstream.Close()

        Dim Sql As String = "Insert into Alloc(Pic) VALUES(@Pic)"
        sql_command = New SqlClient.SqlCommand(Sql, Con)
        sql_command.Connection.Open()
        sql_command.Parameters.AddWithValue("@Pic1", arrImage)
        sql_command.ExecuteNonQuery()
        sql_command.Connection.Close()
    End Sub