Managed C++/CLI

Re: Executing Code on App Exit

20-Apr-09 9:40

You know how to add a Button.Click handler? or a TextBox.TextChanged handler?
It is exactly the same for Form.FormClosed: in Visual Designer select the Control, right click for Properties, use Lightning icon to switch to events, double-click the event you want, that adds and opens the handler's method.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

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turkmeistr120-Apr-09 10:01

turkmeistr1

20-Apr-09 10:01

Awesome! That was very helpful! Thank you so much!

Re: Executing Code on App Exit

Luc Pattyn20-Apr-09 10:03

How to copy/convert System::Object^(unsigned char) to local variable

20-Apr-09 10:03

You're welcome.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

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marcusab18-Apr-09 10:27

Re: How to copy/convert System::Object^(unsigned char) to local variable

18-Apr-09 10:27

I would like to copy the data content of pDataByte to QByte using Microsoft Visual C++ 2008 .NET

Debug Info

Name         Value           Type
pDataByte    {System.Array}  System::Object^
 [0x0]       0x41 ‘A’        unsigned char
 [0x1]       0x42 ‘B’        unsigned char
 [0x2]       0x43 ‘C’        unsigned char
 [0x3]       0x44 ‘D’        unsigned char

QByte        {Length=0x4}    unsigned char[]
 [0x0]       0x00 ‘’         unsigned char
 [0x1]       0x00 ‘’         unsigned char
 [0x2]       0x00 ‘’         unsigned char
 [0x3]       0x00 ‘’         unsigned char

I have tried several approaches, for example:

<br />
//Declare variables<br />
System::Object ^pDataByte;<br />
unsigned char QByte[4];<br />
<br />
//External DLL Function<br />
ReadOutput(pDataByte);<br />
<br />
//Current variable status see "Debug Info"<br />
<br />
//Copy values to local variable<br />
QByte[0] = (unsigned char)System::Convert::ToChar(pDataByte); <br />

Error Code (at runtime at line: QByte[0] = (unsigned char)System...)
An unhandled exception of type 'System.InvalidCastException' occurred in mscorlib.dll
Additional information: Unable to cast object of type 'System.Byte[]' to type 'System.IConvertible'.

Please help, I have tried very hard to get this to work, I am used to plane C++ (not .NET Framework) Sniff | :^)

N a v a n e e t h18-Apr-09 16:42

Re: How to copy/convert System::Object^(unsigned char) to local variable

18-Apr-09 16:42

What is the type of the content in pDataByte? Is that a byte array?

Navaneeth

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marcusab18-Apr-09 23:30

Re: How to copy/convert System::Object^(unsigned char) to local variable

18-Apr-09 23:30

Yes, unsigned char (8-bit, byte) system array to be more specific, see "Debug Info".

Debug Info

Name         Value           Type
pDataByte    {System.Array}  System::Object^
 [0x0]       0x41 ‘A’        unsigned char
 [0x1]       0x42 ‘B’        unsigned char
 [0x2]       0x43 ‘C’        unsigned char
 [0x3]       0x44 ‘D’        unsigned char

QByte        {Length=0x4}    unsigned char[]
 [0x0]       0x00 ‘’         unsigned char
 [0x1]       0x00 ‘’         unsigned char
 [0x2]       0x00 ‘’         unsigned char
 [0x3]       0x00 ‘’         unsigned char

N a v a n e e t h19-Apr-09 6:41

Re: How to copy/convert System::Object^(unsigned char) to local variable [modified]

19-Apr-09 6:41

// Following line is wrong. pDataByte is an object with type as System.Array. 
// You can't cast it as unsigned char
QByte[0] = (unsigned char)System::Convert::ToChar(pDataByte);

First you need to get a unsigned char array from the object. Loop through each element and assign it to QByte. Sample code follows,

// Getting unsigned array from pDataByte
array<unsigned char>^ uChars = static_cast<array<unsigned char>^>(pDataByte);

// filling QByte
for(int i=0; i < uChars->Length; i++)
{
    QByte[i] = uChars[i];
}

Hope that helps Smile | :)

Navaneeth

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marcusab19-Apr-09 11:04

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 11:04

Thanks a lot, that´s not enough, thank you, thank you, thank you!

I used your solution together with the solution from Mark Salsbery

array<unsigned char>^ uChars = static_cast<array<unsigned char>^>(pDataByte);
System::Runtime::InteropServices::Marshal::Copy(uChars, 0, System::IntPtr(QByte), 4);

Thank you both extremely much

modified on Monday, April 20, 2009 5:44 AM

N a v a n e e t h19-Apr-09 15:34

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 15:34

Happy to see it worked Smile | :)

Navaneeth

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Luc Pattyn19-Apr-09 16:10

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 16:10

Of course it worked, three people working as a team should be sufficient to move 4 bytes OMG | :OMG:

Luc Pattyn [Forum Guidelines] [My Articles]

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N a v a n e e t h19-Apr-09 17:02

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 17:02

Luc Pattyn wrote:
three people working as a team should be sufficient to move 4 bytes

Great! Worth for a new sig.

Smile | :)

Navaneeth

How to use google | Ask smart questions

Mark Salsbery20-Apr-09 8:31

Re: How to copy/convert System::Object^(unsigned char) to local variable

20-Apr-09 8:31

Obviously, four people would have been the most efficient team size for this project - one person per byte Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Luc Pattyn20-Apr-09 8:40

Re: How to copy/convert System::Object^(unsigned char) to local variable

20-Apr-09 8:40

If they all spend their time reading The Mythical Man-Month four people may not even be enough...

PS: have been reading some Joel-on-Software lately, so I couldn't join in, sorry.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Avoiding unwanted divs (as in "articles needing approval") with the help of this FireFox add-in

Mark Salsbery19-Apr-09 6:40

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 6:40

marcusab wrote:
I would like to copy the data content of pDataByte to QByte

Here's two ways:

array<Byte> ^pDataByte = gcnew array<Byte>(4);
pDataByte[0] = 0x41;
pDataByte[1] = 0x42;
pDataByte[2] = 0x43;
pDataByte[3] = 0x44;

unsigned char QByte[4];

// Use a pinning pointer
pin_ptr<Byte> p = &pDataByte[0];
memcpy(QByte, p, 4);

// Use Marsal.Copy()
Marshal::Copy(pDataByte, 0, IntPtr(QByte), 4);

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

marcusab19-Apr-09 10:55

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 10:55

Thank you very very very much , you got me going in the right direction, see my answer to Navaneeth for more info.

Almost, pDataByte is a System::Object^ {System.Array}, not an array<unsigned char=""> {Length = 0x4} as with QByte. See debug info:

Name         Value           Type
pDataByte    {System.Array}  System::Object^
 [0x0]       0x41 ‘A’        unsigned char
 [0x1]       0x42 ‘B’        unsigned char
 [0x2]       0x43 ‘C’        unsigned char
 [0x3]       0x44 ‘D’        unsigned char
QByte        {Length=0x4}    unsigned char[]
 [0x0]       0x00 ‘’         unsigned char
 [0x1]       0x00 ‘’         unsigned char
 [0x2]       0x00 ‘’         unsigned char
 [0x3]       0x00 ‘’         unsigned char

So I get compilation error:

<br />
error C2665: 'System::Runtime::InteropServices::Marshal::Copy' : none of the 16 overloads could convert all the argument types<br />

Mark Salsbery19-Apr-09 11:12

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 11:12

marcusab wrote:
pDataByte is a System::Object^ {System.Array}, not an array

An array IS a System.Array, but I missed your declaration - sorry about that!

You need the cast Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

marcusab19-Apr-09 11:32

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 11:32

By the way, how do I create the variable pDataByte (now I recevie it from an external DLL).

I would like to do someting like this:

System::Object ^pDataByte = gcnew System::Object(System::Array<<System::Byte>>(4));

To get this:

Name         Value           Type
pDataByte    {System.Array}  System::Object^
 [0x0]       0x00 ‘’         unsigned char
 [0x1]       0x00 ‘’         unsigned char
 [0x2]       0x00 '’         unsigned char
 [0x3]       0x00 ‘’         unsigned char

marcusab19-Apr-09 11:44

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 11:44

Never mind ... D'Oh! | :doh:

System::Object ^pDataByte = gcnew array<System::Byte>(4);

Again, thank you very much Smile | :)

Mark Salsbery19-Apr-09 11:44

Re: How to copy/convert System::Object^(unsigned char) to local variable

19-Apr-09 11:44

Why not use the strong type instead of a System::Object^ ?

array<Byte> ^pDataByte = gcnew array<Byte>(4);

If you must use System::Object^...

System::Object ^pDataByte = gcnew array<Byte>(4);

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

marcusab19-Apr-09 11:57

19-Apr-09 11:57

Thanks again, you are the man Smile | :)

DialogBox in C++/CLI

J_E_D_I9-Apr-09 11:29

J_E_D_I

9-Apr-09 11:29

Hi, I can't find any decent example on how to create a DialogBox using C++/CLI and on how to deal with the different responses triggered by the diffent buttons being pressed.

I've created graphically the DialogBox (form2) which has 2 buttons "A" and "B" but I can't understand how I can pass different values to the main form (form1) when each button is selected. Is it possible to do it without creating a new class. How?

Any example code would be highly appreciated.

Re: DialogBox in C++/CLI

Mark Salsbery9-Apr-09 12:26