vb 6 code converstion in C#

Question

1.00/5 (1 vote)

See more:

Hi i am converting your vb code into c# but having error kindly guide me if i am doing something wrong.

////////////vb code///////////////

VB

Public Declare Function IO_HasScanner Lib "scandll.dll" (ByVal IVS_600DS As String, ByVal hHandle As Long) As Long

Private Sub CmdConnect_Click()
Dim lRet As Long

lRet = IO_HasScanner("IDCapture", Me.hwnd)
If lRet = 0 Then
    Text1.Text = "Scanner connected."
    bLoaded = True
    CmdConnect.Enabled = False
    OptionManual.Value = True
    strGreyImageFile = "G01.bmp"
    strColorImageFile = "C01.bmp"
    strGreyImageFile_Head = "GH01.bmp"
    strColorImageFile_Head = "CH01.bmp"
Else
    Text1.Text = "Device not connected."
    bLoaded = False
    CmdConnect.Enabled = True
End If
End Sub

/////////c# 4.0 code////////

C#

[DllImport("ScanDll.dll")]
        public static extern long IO_HasScanner(string IVS_600DS, long hHandle);

        private void Form1_Load(object sender, EventArgs e)
        {
            long result;
            result = IO_HasScanner("IDCapture", this.Handle.ToInt32()); //// Get Error on this line.
            MessageBox.Show(result.ToString());
        }

Posted 14-Jun-14 4:06am

Farhan Qureshi

Updated 14-Jun-14 4:09am

DamithSL

v2

Add a Solution

Comments

CPallini 14-Jun-14 10:12am

What kind of error are you getting?

Farhan Qureshi 14-Jun-14 10:16am

A call to PInvoke function 'scanTest!scanTest.Form1::IO_HasScanner' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.

[no name] 14-Jun-14 10:13am

Well there are several things wrong here. You could not possibly be porting any VB6 code that I wrote to C#. You should not be porting VB6 code to .NET, you should be rewriting it. And we could not possibly know which error it is that you are seeing out of the hundreds of errors that it could be.

Farhan Qureshi 14-Jun-14 10:16am

A call to PInvoke function 'scanTest!scanTest.Form1::IO_HasScanner' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.

[no name] 14-Jun-14 10:24am

"Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature."

3 solutions

Solution 1

Well yes - you will.
A long is not the same as an Int32 - it's an Int64
Try:

C#

long result;
result = IO_HasScanner("IDCapture", this.Handle.ToInt64());

Posted 14-Jun-14 4:16am

OriginalGriff

Comments

Farhan Qureshi 14-Jun-14 10:19am

A call to PInvoke function 'scanTest!scanTest.Form1::IO_HasScanner' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.

CPallini 14-Jun-14 10:45am

Well, a VB6 Long is not exactly 64 bit wide. :-)

Dave Kreskowiak 14-Jun-14 11:09am

You might want to be a bit more specific.

A Long in VB6 is an Int32 in C#.

Farhan Qureshi 14-Jun-14 11:34am

http://fileflyer.com/view/Foa2FAW

Dave Kreskowiak 14-Jun-14 14:17pm

...and what is this link for?

No, I'm not clicking on it.
No, I'm downloading your project if that is what this is.

Farhan Qureshi 14-Jun-14 11:16am

scandll.dll is written in C++
and code of vb6.0 is working fine i want to write same code in C# but having this silly error.

Farhan Qureshi 14-Jun-14 11:35am

http://fileflyer.com/view/Foa2FAW
i have uploaded the project see if you can help me

Solution 2

Maybe you can try this now - long changed to Int32

C#

[DllImport("ScanDll.dll")]
public static extern Int32 IO_HasScanner([MarshalAs(UnmanagedType.VBByRefStr)] ref string IVS_600DS, Int32 hHandle);

private void Form1_Load(object sender, EventArgs e)
{
   Int32 result;
   result = IO_HasScanner("IDCapture", this.Handle.ToInt32()); 
   MessageBox.Show(result.ToString());
}

Posted 14-Jun-14 4:28am

TheUnknownCoder

Updated 14-Jun-14 4:49am

v3

Comments

Farhan Qureshi 14-Jun-14 10:31am

still same error

[DllImport("ScanDll.dll")]
public static extern long IO_HasScanner([MarshalAs(UnmanagedType.VBByRefStr)] ref string IVS_600DS, long hHandle);

private void Form1_Load(object sender, EventArgs e)
{
long result;
string txt = "IDCapture";
result = IO_HasScanner(ref txt, this.Handle.ToInt64());
MessageBox.Show(result.ToString());
}

TheUnknownCoder 14-Jun-14 10:49am

see new solution

Farhan Qureshi 14-Jun-14 10:51am

still same
:(

Farhan Qureshi 14-Jun-14 10:52am

[DllImport(@"ScanDll.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern long IO_HasScanner([MarshalAs(UnmanagedType.VBByRefStr)] ref string IVS_600DS, Int32 hHandle);

private void Form1_Load(object sender, EventArgs e)
{
long result;
string txt = "IDCapture";
result = IO_HasScanner(ref txt, this.Handle.ToInt32());
MessageBox.Show(result.ToString());
}

TheUnknownCoder 14-Jun-14 10:53am

sorry, can´t try it, no scanner .... and no scandll.dll

Farhan Qureshi 14-Jun-14 11:34am

http://fileflyer.com/view/Foa2FAW

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Farhan Qureshi · Accepted Answer · 2014-06-15T20:54:00

just data type mismatch

i was using long instead of int32.

C#

[DllImport(@"ScanDll.dll")]
public static extern Int32 IO_HasScanner(string IVS_600DS, int hHandle);

private void Form1_Load(object sender, EventArgs e)
{
    long result;
    result = IO_HasScanner("IDCapture", this.Handle.ToInt32());
    MessageBox.Show(result.ToString());
}

vb 6 code converstion in C#

3 solutions

Solution 1

Solution 2

Solution 3

Add your solution here

Preview 0

Existing Members

...or Join us