I need help - I can help - Getting Started with the dll in VB.Net

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Getting Started with the dll in VB.Net

Printed From: Debenu Quick PDF Library - PDF SDK Community Forum
Category: For Users of the Library
Forum Name: I need help - I can help
Forum Description: Problems and solutions while programming with the Debenu Quick PDF Library and Debenu PDF Viewer SDK
URL: http://www.quickpdf.org/forum/forum_posts.asp?TID=2028
Printed Date: 27 Apr 25 at 2:48PM
Software Version: Web Wiz Forums 11.01 - http://www.webwizforums.com

Topic: Getting Started with the dll in VB.Net

Posted By: Dan
Subject: Getting Started with the dll in VB.Net
Date Posted: 03 Nov 11 at 3:16PM

Hi,

I'm having trouble getting the dll version 8.12 working in VB.Net. The Getting Started was a little help..

I understand access to the library is done via the file C:\Program Files (x86)\Quick PDF Library\DLL\Import\VB.NET\QuickPDFDLL0812.vb, which I copied into my project App_Code directory.

The guide doesn't say what to do with the dll. I can't reference it through VS's Add Reference dialog. I get this error:
A reference to 'C:\Program Files (x86)\Quick PDF Library\DLL\QuickPDF64DLL0812.dll' could not be added. No type libraries were found in the component.

Also,
Visual Studio can't find the method QuickPDFDLL0812.QuickPDFCreateLibrary() as shown in the example in the Getting Started guide.

The only thing it can find is: QuickPDFDLL0812.PDFLibrary

So I downloaded the VB.Net code sample project here: http://www.quickpdflibrary.com/samples/index.php

First thing I notice is it uses version 7.21. Is there a current example?

Anyways, I unzipped and loaded the project into Visual Studio 2010, letting VS update the project to be used with 2010. Then I updated Form1.vb by updating the LicenseKey and changed the path to the .dll to:
QP = New PDFLibrary("QuickPDFDLL0721.dll")

I also tried leaving it:
QP = New PDFLibrary("../../QuickPDFDLL0721.dll")

Regardless, when I run or debug the project I get an error after clicking the "HelloWorld" button on the form on line 29 of QuickPDFDLL0721.vb:

QuickPDFAddArcToPath = DirectCast(Marshal.GetDelegateForFunctionPointer(GetProcAddress(dllHandle, "QuickPDFAddArcToPath"), GetType(DelegateIIDDD)), DelegateIIDDD)

The error is:
System.ArgumentNullException was unhandled
Message=Value cannot be null.
Parameter name: ptr
ParamName=ptr
Source=mscorlib
StackTrace:
       at System.Runtime.InteropServices.Marshal.GetDelegateForFunctionPointer(IntPtr ptr, Type t)
       at visual_basic_dll_sample.QuickPDFDLL0721.DLL..ctor(String dllFileName) in D:\Projects\Examples\visual-basic_dll_sample\QuickPDFDLL0721.vb:line 29
       at visual_basic_dll_sample.QuickPDFDLL0721.PDFLibrary..ctor(String dllFileName) in D:\Projects\Examples\visual-basic_dll_sample\QuickPDFDLL0721.vb:line 1303
       at visual_basic_dll_sample.Form1.btnHelloWorld_Click(Object sender, EventArgs e) in D:\Projects\Examples\visual-basic_dll_sample\Form1.vb:line 13
       at System.Windows.Forms.Control.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ButtonBase.WndProc(Message& m)
       at System.Windows.Forms.Button.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
       at visual_basic_dll_sample.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
InnerException:

Replies:

Posted By: Dan
Date Posted: 03 Nov 11 at 3:22PM

I got a little further using the code sample project as a guide and this post: http://www.quickpdf.org/forum/using-c-and-the-dll-edition-of-quick-pdf-library_topic1110.html - http://www.quickpdf.org/forum/using-c-and-the-dll-edition-of-quick-pdf-library_topic1110.html

I tried copying the dll into the root of my own test project (and into the Bin folder but not at the same time) and I can't get the library loaded. Here is my code:

Dim QP As PDFLibrary = New PDFLibrary("/Bin/QuickPDF64DLL0812.dll")
Dim Loaded As Boolean = QP.LibraryLoaded()
If Not Loaded Then
     Throw New Exception("Not Loaded")
End If
Dim Result As Int32 = QP.UnlockKey(QuickPDFKey8)
If Result = 1 Then
     QP.SetOrigin(1)
     QP.DrawText(100, 100, "XOIJSDFOJSDIOFJSODJFOISDJ")

     QP.CompressContent()

     Dim bytes As Byte() = QP.SaveToString()

     Response.Clear()
     Response.ContentType = "application/pdf"
     Response.AddHeader("Content-Disposition", "attachment; filename=test.pdf")
     Response.OutputStream.Write(bytes, 0, bytes.Length)
     Response.OutputStream.Flush()
     Response.OutputStream.Close()
     Response.End()
Else
     Throw New Exception("Not Unlocked.")
End If

Where do I put this dll and how do I reference it?

Thanks,
Dan

Posted By: darkv
Date Posted: 04 Nov 11 at 6:59AM

Dan,

The dll could be anywhere, with any name, as soon as you referenced it correctly

Personnaly what i used is :

lpPdfLib = c:\mypath\zlib.dll
myPdf = New PDFLibrary(lpPdfLib)

and it works perfectly..

to test, copy dll in release and debug directories in your project, in your code just call it by its name only w/o path and should work

Good luck

Eric

Posted By: AndrewC
Date Posted: 04 Nov 11 at 7:35AM

Here is my code sample for VB.NET

The DLL needs to be somewhere where the EXE file can find it. This can be

1. The same directory as the EXE file

2. You can specify where the DLL is Dim QP As PDFLibrary = New PDFLibrary("C:/Bin/QuickPDF64DLL0813.dll") // can use absolute or relative path.

2. In C:\Windows\System32 for 32 bit verisions of Windows (32bit DLL or 64bit DLL)

3. In C:\Windows\SysWOW64 for 64 bit verisions of Windows (32bit DLL)

Looking at the above code, you are using the 64 bit DLL with VB.NET but your project was probably targetted to compile a 32b bit EXE. So you may need to go into the Build Menu then Configuration Manager to make sure you are targeting a 64 bit app. If it is 32bits then you need to use 'QuickPDFDLL0813.DLL' - ie the 32 bit version.

I have successfully tested this with both 32 and 64 bit DLL's.

' ------------------------------------------------------------------------------------------------------------------

Imports QPL_VB_NET.QuickPDFDLL0813 // Replace QPL_VB_NET with the name of your APP.

Public Class Form1

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

Dim QP As PDFLibrary

Dim LicenseKey

Dim Result

' Update path to DLL if necessary

' Check the Project, Configuration Manager

QP = New PDFLibrary("QuickPDF64DLL0813.dll") ' use "QuickPDFDLL0813.dll" for 32 bits

' Insert your trial or commercial license key here

LicenseKey = "<put your license key here>"

Result = QP.UnlockKey(LicenseKey)

If Result = 1 Then

' This function sets the origin

' for the co-ordinates used by

' the drawing functions.

QP.SetOrigin(1)

' The DrawText function lets you

' draw text onto a page.

QP.DrawText(100, 100, "Hello Visual Basic! This text has been drawn using the DrawText function.")

QP.DrawHTMLText(100, 125, 400, "<b>Quick PDF Library Version:</b> " + QP.LibraryVersion())

QP.DrawHTMLText(100, 140, 400, "<b>License Information:</b> " + QP.LicenseInfo())

' The DrawBox function lets you

' draw rectangular shapes.

QP.DrawBox(50, 50, 500, 150, 0)

' Save the new file to disk.

If QP.SaveToFile("Hello_World.pdf") = 1 Then

lblStatus.Text = "Success! Look in the Test Files folder."

Else

lblStatus.Text = "Oh no, the file was not saved correctly."

End If

Else

MsgBox("- Invalid license key -")

End If

QP = Nothing

End Sub

End Class

Posted By: AndrewC
Date Posted: 04 Nov 11 at 7:37AM

We made some fixes to the VB.NET import file in 8.13 so you may also have better success with 8.13 beta which can be downloaded from

http://www.quickpdflibrary.com/blog/2011/11/quick-pdf-library-8-13-beta-1-released/ - http://www.quickpdflibrary.com/blog/2011/11/quick-pdf-library-8-13-beta-1-released/

Andrew.

Posted By: Dan
Date Posted: 04 Nov 11 at 1:56PM

Thanks Eric and Andrew!

I don't think I have an .exe because this is a web page. I got it working with an absolute path to the 32bit version:
Dim QP As PDFLibrary = New PDFLibrary("C:/Bin/QuickPDFDLL0812.dll")

"you may also have better success with 8.13 beta"
I tend to shy away from beta releases because they haven't gone through a complete QA process.

But what exactly was wrong with the VB.Net import file? I may have to make an exception..

Thanks,
Dan