Re: AccessViolationException when using the qapuiek.dll - C# Discussion Boards

Re: AccessViolationException when using the qapuiek.dll

20-May-09 4:56

1. change the C# prototype, from "myFunc(..., string rs4, ...)" to "myFunc(...,StringBuilder rs4,...)".

2.
Make sure to create the SB beforehand and give it ample capacity, something like:

StringBuilder sb=new StringBuilder(1000);
myFunc(..., sb, ...);
string rs4=sb.ToString();

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TheFoZ20-May-09 5:04

TheFoZ

20-May-09 5:04

Thanks again Luc

One of the things I missed from the VB code is that rsBuffer should be 9 characters in length. Once I changed the to the string builder with a length of 9 I got the correct value returned.

1 function down, 9 to go.

Cheers Smile | :)

The FoZ

Re: AccessViolationException when using the qapuiek.dll

Luc Pattyn20-May-09 5:43

Re: AccessViolationException when using the qapuiek.dll

20-May-09 5:43

you're welcome.

Smile | :)

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Dave Kreskowiak20-May-09 5:53

Dave Kreskowiak

20-May-09 5:53

TheFoZ wrote:
//Declarations
//Declare Sub QAInitialise Lib "QAPUIEK.DLL" (ByVal vi1 As Long)
[DllImport("qapuiek.dll")]
public static extern int QAInitialise(long vi1);

Change the long parameter declaration to an int.

In VBA and VB6 code, the type Long is a 32-bti signed integer. In C# and VB.NET, that's an int, Integer, or System.Int32.

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Visual Developer - Visual Basic
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Re: AccessViolationException when using the qapuiek.dll

Luc Pattyn20-May-09 6:05

Re: AccessViolationException when using the qapuiek.dll

20-May-09 6:05

Right. I missed that one.
However, it did survive the long/int mistake, showing the one advantage of little-endianness.

Smile | :)

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Dave Kreskowiak20-May-09 6:28

Dave Kreskowiak

20-May-09 6:28

Lucky, lucky, lucky...

OT: Am I the only one who thinks of this[^] when I see "little-endianness"??

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Dave Kreskowiak
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Visual Developer - Visual Basic
2006, 2007, 2008

Re: AccessViolationException when using the qapuiek.dll

Luc Pattyn20-May-09 6:42

Removing AutoIncrement from Access database column

20-May-09 6:42

Dave Kreskowiak wrote:
Am I the only one who thinks...

AFAIK yes you are.

Smile | :)

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Windows service apps

saeidfarahi20-May-09 3:11

saeidfarahi

20-May-09 3:11

I have made a solution in VS2008 using c# and it's functionality is reading from COM port and monitor the results in some forms and save some of the data in an sql or access database,as well.Now I want make my app as a service to be run before anyone has logged in windows.I have read something about a software but I wanna know how can I do this using .net.

Re: Windows service apps

PIEBALDconsult20-May-09 3:25

PIEBALDconsult

20-May-09 3:25

WindowsService with .NET[^]

Eduard Keilholz20-May-09 2:51

Eduard Keilholz

20-May-09 2:51

Hey!

I'm trying to remove the AutoIncrement from an MS Access database. I'm using ADOX. The table has two foreign relations, these relations are removed (which works fine), however when I try to remove the Autoincrement property from the column, i receive the following exception :

Multiple-step OLE DB operation generated errors. Check each OLE DB status value, if available. No work was done.

m_catDatabase.let_ActiveConnection(m_strConnectionString);
 foreach (Key keyRelation in m_catDatabase.Tables["Kengetallen"].Keys)
 {
     if ((keyRelation.Type == KeyTypeEnum.adKeyForeign) && (keyRelation.RelatedTable == "ProductGroep"))
     {
         m_catDatabase.Tables["Kengetallen"].Keys.Delete(keyRelation.Name);
         break;
     }
 }
 foreach (Key keyRelation in m_catDatabase.Tables["Product"].Keys)
 {
     if ((keyRelation.Type == KeyTypeEnum.adKeyForeign) && (keyRelation.RelatedTable == "ProductGroep"))
     {
         m_catDatabase.Tables["Product"].Keys.Delete(keyRelation.Name);
         break;
     }
 }

 Column clmnProdGroepID = m_catDatabase.Tables["ProductGroep"].Columns["ProductGroep_ID"];
 clmnProdGroepID.Properties["Autoincrement"].Value = false;

The last line of code throws the exception.

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froms in MDI

sachees12320-May-09 2:42

sachees123

20-May-09 2:42

Frnds,

IN MDI application whn one form is open and than want to open another form. How to close/hide the previous form?

Re: froms in MDI

musefan20-May-09 2:48

Re: froms in MDI [modified]

20-May-09 2:48

To Close a form...

this.Close();

To Hide a form... Can you guess what it is yet?...

this.Hide();

If this is not enough of an answer then you need to try explaining your situation better

Life goes very fast. Tomorrow, today is already yesterday.

Re: froms in MDI

sachees12320-May-09 3:17

sachees123

20-May-09 3:17

OK, this i Know. Lemme explain :

when i run my application my default form opens which is going to contain the child form. Now on that form i have my menustrip which contains multiple forms links.

When i select any of them than that form opens on the default form(without closing the default form) and when i again open the next form than the previous is still in open state. So at this point all three forms are open one over other.

This where i need to close the previous form.

musefan20-May-09 3:24

Why Printing events not fired

20-May-09 3:24

OK so you are basically saying that you only want one child form open at a time?

Well when you open a child form, you need to keep a reference to it somewhere, like in you main form you have a global variable like...

Form openForm;

... then when you open a new child form (by clicking one of the links) then you test to see if one is open already, close it if so, then open the new child form like so...

void ButtonClick(object sender, EventArgs e)
{
  if(!(openForm == null || openForm.IsDisposed))
  {
     openForm.Close();
  }
  openForm = newChildForm();
  openForm.Show();
}

Life goes very fast. Tomorrow, today is already yesterday.

modified on Thursday, May 21, 2009 5:54 AM

Re: froms in MDI

sachees12320-May-09 23:45

sachees123

20-May-09 23:45

Thanks, it works

svt gdwl20-May-09 2:32

svt gdwl

20-May-09 2:32

when we give the print from internet explorer,
any of the Printing events are not fired?
Why? This was the code I'm trying with

System.Drawing.Printing.PrintDocument Pd = webBrowser.Document as System.Drawing.Printing.PrintDocument;
            Pd.Print();
            Pd.BeginPrint += new System.Drawing.Printing.PrintEventHandler(Pd_BeginPrint);
            Pd.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(Pd_PrintPage);
            Pd.EndPrint += new System.Drawing.Printing.PrintEventHandler(Pd_EndPrint);

Here webBrowser gives the Internet Explorer reference?
How can I get these events get fired?

Manas Bhardwaj20-May-09 2:38

Manas Bhardwaj

20-May-09 2:38

Printing is always done at client side and not at the server.

Have a look here[^].

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musefan20-May-09 2:52

20-May-09 2:52

those events have been attached to a specific instance of a PrintDocument and will only fire when that PrintDocument calls for those functions.

your code is calling the Print(); function of the PrintDocument but your events are not attached until afterwards.... Thou I suspect you wont be able to get it working if you did call Print(); after you attached the events, but we shall see about that Laugh | :laugh:

Life goes very fast. Tomorrow, today is already yesterday.

svt gdwl20-May-09 3:04

svt gdwl

20-May-09 3:04

when I consider the browser document as PrintDocument,
when we give the page for Print through File->Print-> select the required printer ->OK

but also, none of the above events gets fired?
what may be the reason?

System.Drawing.Printing.PrintDocument Pd = new System.Drawing.Printing.PrintDocument();
         //  System.Drawing.Printing.PrintDocument Pd = webBrowser.Document as System.Drawing.Printing.PrintDocument;
         //  Pd.Print();
           Pd.BeginPrint +=new System.Drawing.Printing.PrintEventHandler(Pd_BeginPrint);
           Pd.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(Pd_PrintPage);
           Pd.EndPrint += new System.Drawing.Printing.PrintEventHandler(Pd_EndPrint);

This also doesn't make any event get fired?

harold aptroot20-May-09 3:09

harold aptroot

20-May-09 3:09

You forgot to print?

musefan20-May-09 3:12