PrintDocument failed to print the second time - vb.net

Question

Here is the full code
Imports System.Data.OleDb
Public Class veterinarycgpa
Private Sub veterinarycgpa_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim matricno, sessionad As String
matricno = pretranscript.matric.Text
sessionad = pretranscript.session.Text
'semester = checkresult.semester.Text
Dim allunit, allwgp As Decimal
Try
Dim con As New System.Data.OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0; Data Source=cgpa.accdb")
Dim cmd As New System.Data.OleDb.OleDbCommand
If con.State = ConnectionState.Closed Then
con.Open()
End If
Dim dr As OleDbDataReader
cmd.CommandText = System.Data.CommandType.Text
Dim str As String
str = "SELECT [fullname],[matric], [maiden_name], [gender], [session_admitted], [mode_of_entry], [programme] FROM student WHERE [matric]='" & matricno & "' AND [session_admitted] = '" & sessionad & "' "
Dim cd As OleDbCommand = New OleDbCommand(str, con)
dr = cd.ExecuteReader
dr.Read()
If dr("matric") = pretranscript.matric.Text Then 'checkresult.matric.Text
fullname.Text = dr("fullname").ToString
matric.Text = dr("matric").ToString
mname.Text = dr("maiden_name").ToString
session.Text = dr("session_admitted").ToString
gender.Text = dr("gender").ToString
mode_of_entry.Text = dr("mode_of_entry").ToString
programme.Text = dr("programme").ToString
End If
'MsgBox("No Result found for the given matric no and session", MsgBoxStyle.Critical)
con.Close()
If con.State = ConnectionState.Closed Then
con.Open()
End If
str = " SELECT [matric], [session], [pvp711] ,[pvp713] ,[pvp719] ,[pvp703] ,[pvp715], [pvp717], [pvp701] FROM veterinaryone WHERE [matric]='" & matricno & "' AND [session] = '" & sessionad & "'"
Dim cd1 As OleDbCommand = New OleDbCommand(str, con)
dr = cd1.ExecuteReader
dr.Read()
If dr("matric") = pretranscript.matric.Text Then
score1.Text = dr("pvp711").ToString
score2.Text = dr("pvp713").ToString
score3.Text = dr("pvp719").ToString
score4.Text = dr("pvp703").ToString
score5.Text = dr("pvp715").ToString
score6.Text = dr("pvp717").ToString
score7.Text = dr("pvp701").ToString
End If
con.Close()
If con.State = ConnectionState.Closed Then
con.Open()
End If
str = " SELECT [matric], [session], [pvp710] ,[pvp712] ,[pvp714] ,[pvp716] ,[pvp702], [pvp704], [pvp718], [pvp722], [pau3101], [pau3104] FROM veterinarytwo WHERE [matric]='" & matricno & "' AND [session] = '" & sessionad & "'"
Dim cd2 As OleDbCommand = New OleDbCommand(str, con)
dr = cd2.ExecuteReader
dr.Read()
If dr("matric") = pretranscript.matric.Text Then
score8.Text = dr("pvp710").ToString
score9.Text = dr("pvp712").ToString
score10.Text = dr("pvp714").ToString
score11.Text = dr("pvp716").ToString
score12.Text = dr("pvp702").ToString
score13.Text = dr("pvp704").ToString
score14.Text = dr("pvp718").ToString
score15.Text = dr("pvp722").ToString
score16.Text = dr("pau3101").ToString
score17.Text = dr("pau3104").ToString
End If
con.Close()
If con.State = ConnectionState.Closed Then
con.Open()
End If
str = " SELECT [matric], [session], [pvp721] FROM veterinarythree WHERE [matric]='" & matricno & "' AND [session] = '" & sessionad & "'"
Dim cd3 As OleDbCommand = New OleDbCommand(str, con)
dr = cd3.ExecuteReader
dr.Read()
If dr("matric") = pretranscript.matric.Text Then
score18.Text = dr("pvp721").ToString
End If
con.Close()
If con.State = ConnectionState.Closed Then
con.Open()
End If
str = " SELECT [matric], [session], [pvp720], [pvp724] FROM veterinaryfour WHERE [matric]='" & matricno & "' AND [session] = '" & sessionad & "'"
Dim cd4 As OleDbCommand = New OleDbCommand(str, con)
dr = cd4.ExecuteReader
dr.Read()
If dr("matric") = pretranscript.matric.Text Then
score19.Text = dr("pvp720").ToString
score20.Text = dr("pvp724").ToString
End If
con.Close()
Catch ex As Exception
MsgBox(ex.Message, MsgBoxStyle.Information, "ALERT")
End Try
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Button1.Visible = False
Button2.Visible = False
PrintPreviewDialog1.Document = PrintDocument1
'PrintPreviewDialog1.PrintPreviewControl.Zoom = 1
PrintPreviewDialog1.ShowDialog()
'PrintDocument1.DefaultPageSettings.Landscape = True
PrintDocument1.Print()
Button1.Visible = True
Button2.Visible = True
End Sub
Private Sub PrintDocument1_PrintPage(sender As Object, e As Printing.PrintPageEventArgs) Handles PrintDocument1.PrintPage
Dim groupbox As New Bitmap(Me.Width, Me.Height)
Me.DrawToBitmap(groupbox, New Rectangle(0, 0, Me.Width, Me.Height))
e.Graphics.DrawImage(groupbox, 0, 0)
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Me.Close()
End Sub
End Class
I have other forms containing code like this as well, so if I print from this, it print to PDF automatically successfully, but if I close the form and open it again or any other form to print the second time then it breaks and brings about this error.
First-chance exception at 0x5adf7ecf (dui70.dll) in Pau_CGPA.exe: 0xC0000005: Access violation reading location 0x0000001c.
Unhandled exception at 0x5adf7ecf (dui70.dll) in Pau_CGPA.exe: 0xC000041D: 0xC000041D: An unhandled exception was encountered during a user callback.
So I don't know what is wrong.

Answer 1

Here's some points to consider:
Use the same objects as long as that is possible. No need to create new OleDbCommand cd1, cd2, ..etc. Just create one and reuse it by changing its CommandText and update its Parameters.
Always use parameterized queries and avoid string concatenating the SQL statements like WHERE [matric]='" & matricno.
When you create a new OleDbConnection the connection remains closed until you call the Open method explicitly. So checking the connection State just right after creating the object doesn't make any sense.
Keep the connection opened as long as you need to use the same connection again and again. So no need to close and reopen it.
The Read method and the HasRows property both return True if the OleDbDataReader has something to read.
You should dispose the disposable objects, always create them in Using blocks.
Now, applying that on the Load event block would produce:
Imports System.Data.OleDb
Imports System.Drawing.Printing
'...
Private Sub veterinarycgpa_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim matricno = pretranscript.matric.Text
Dim sessionad = pretranscript.session.Text
Try
Using con As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0; Data Source=cgpa.accdb"),
cmd As New OleDbCommand("SELECT [fullname], [matric], [maiden_name], [gender], [session_admitted], [mode_of_entry], [programme] FROM [student] WHERE [matric] = ? AND [session_admitted] = ?", con)
'Better to use the Add(..) method instead and define the right OleDbType and size...
cmd.Parameters.AddWithValue("matric", matricno)
cmd.Parameters.AddWithValue("session_admitted", sessionad)
con.Open()
Using dr = cmd.ExecuteReader
If dr.Read() Then
fullname.Text = dr("fullname").ToString
matric.Text = dr("matric").ToString
mname.Text = dr("maiden_name").ToString
session.Text = dr("session_admitted").ToString
gender.Text = dr("gender").ToString
mode_of_entry.Text = dr("mode_of_entry").ToString
programme.Text = dr("programme").ToString
End If
End Using
cmd.Parameters.Clear()
cmd.CommandText = "SELECT [matric], [session], [pvp711], [pvp713], [pvp719], [pvp703], [pvp715], [pvp717], [pvp701] FROM [veterinaryone] WHERE [matric] = ? AND [session] = ?"
cmd.Parameters.AddWithValue("matric", matricno)
cmd.Parameters.AddWithValue("session", sessionad)
Using dr = cmd.ExecuteReader
If dr.Read() Then
score1.Text = dr("pvp711").ToString
score2.Text = dr("pvp713").ToString
score3.Text = dr("pvp719").ToString
score4.Text = dr("pvp703").ToString
score5.Text = dr("pvp715").ToString
score6.Text = dr("pvp717").ToString
score7.Text = dr("pvp701").ToString
End If
End Using
cmd.Parameters.Clear()
cmd.CommandText = "SELECT [matric], [session], [pvp710], [pvp712], [pvp714], [pvp716], [pvp702], [pvp704], [pvp718], [pvp722], [pau3101], [pau3104] FROM [veterinarytwo] WHERE [matric] = ? AND [session] = ?"
cmd.Parameters.AddWithValue("matric", matricno)
cmd.Parameters.AddWithValue("session", sessionad)
Using dr = cmd.ExecuteReader
If dr.Read() Then
score8.Text = dr("pvp710").ToString
score9.Text = dr("pvp712").ToString
score10.Text = dr("pvp714").ToString
score11.Text = dr("pvp716").ToString
score12.Text = dr("pvp702").ToString
score13.Text = dr("pvp704").ToString
score14.Text = dr("pvp718").ToString
score15.Text = dr("pvp722").ToString
score16.Text = dr("pau3101").ToString
score17.Text = dr("pau3104").ToString
End If
End Using
cmd.Parameters.Clear()
cmd.CommandText = "SELECT [matric], [session], [pvp721] FROM [veterinarythree] WHERE [matric] = ? AND [session] = ?"
cmd.Parameters.AddWithValue("matric", matricno)
cmd.Parameters.AddWithValue("session", sessionad)
Using dr = cmd.ExecuteReader
If dr.Read() Then
score18.Text = dr("pvp721").ToString
End If
End Using
cmd.Parameters.Clear()
cmd.CommandText = "SELECT [matric], [session], [pvp720], [pvp724] FROM [veterinaryfour] WHERE [matric]= ? AND [session] = ?"
cmd.Parameters.AddWithValue("matric", matricno)
cmd.Parameters.AddWithValue("session", sessionad)
Using dr = cmd.ExecuteReader
If dr.Read() Then
score19.Text = dr("pvp720").ToString
score20.Text = dr("pvp724").ToString
End If
End Using
End Using
Catch ex As Exception
MsgBox(ex.Message, MsgBoxStyle.Information, "ALERT")
End Try
End Sub
As for the printing part:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
PrintDialog1.Document = PrintDocument1
If PrintDialog1.ShowDialog = DialogResult.OK Then
PrintDialog1.Document.Print()
End If
End Sub
Private Sub PrintDocument1_BeginPrint(sender As Object, e As PrintEventArgs) Handles PrintDocument1.BeginPrint
Button1.Visible = False
Button2.Visible = False
End Sub
Private Sub PrintDocument1_PrintPage(sender As Object, e As PrintPageEventArgs) Handles PrintDocument1.PrintPage
Using bmp As New Bitmap(Width, Height)
DrawToBitmap(bmp, New Rectangle(0, 0, Width, Height))
e.Graphics.DrawImage(bmp, 0, 0)
'You might want to try:
'e.Graphics.DrawImage(bmp, ea.PageBounds.X, ea.PageBounds.Y, ea.PageBounds.Width, ea.PageBounds.Height)
'e.Graphics.DrawImage(bmp, ea.MarginBounds.X, ea.MarginBounds.Y, ea.MarginBounds.Width, ea.MarginBounds.Height)
End Using
End Sub
Private Sub PrintDocument1_EndPrint(sender As Object, e As PrintEventArgs) Handles PrintDocument1.EndPrint
Button1.Visible = True
Button2.Visible = True
End Sub
Accordingly, you can delete both the PrintPreviewDialog1 and PrintDocument1. And don't forget to delete the PrintDocument1_PrintPage handler.