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Hi,
I am using Visual Studio 2005 to develop an MDI application in C++/CLI. The application contains both child windows and non-child tool windows.
The child window(s) has a menu that integrates with the main application menu. The problem is that when a non-child tool window is active then I must click the menu (in the main application window) twice to activate it; once to activate the application (parent) window and a second time to activate the menu. If a child window is active then the menu operates with just one click. In the old version of my progam, which was developed in managed C++ under Visual Studio 2003, only one click was required to activate the main menu when a tool window was active.
This behaviour of my application is annoying and unprofessional. I was wondering if anybody had any ideas on how to fix this or what is causing it? Thanks!
zenzero
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I guess that nobody has any ideas? Is this a bug in .net 2.0 or am I just being dumb?
May be I should try posting on the C# forum?
Any advice would be greatly appreciated.
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Hi,
I've written a managed class that makes use of stl vectors of a few unmanaged structs for data handling/manipulation, but I'm getting a few very strange errors. I get an "Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object" occasionally when adding a new element to a vector. By occasionally I mean that the exact same code works fine most of the time, throwing the error around 1% of the time. Based on sample data that I'm feeding the program, the errors occur on the exact same data every execution, but I don't see anything wrong with the offending data or the code. Can someone help? Even if you only have a vague idea of something I can look into, please let me know.
Here's the relevant code snippet:
// if a headline occurs after a normal paragraph, split the block there
for (int i = thisDoc->blocks.size() - 1; i >= 0; i--)
{
block* curBlock = &thisDoc->blocks[i];
if (curBlock->type == blockType::text)
{
// search through all the paragraphs (from end to start)
bool lastWasHeadline = false;
for (int j = curBlock->paragraphs.size() - 1; j >= 0; j--)
{
// is this paragraph a headline?
if (curBlock->paragraphs[j].type == paragraphType::headline)
lastWasHeadline = true;
else
{
// did we just leave a headline?
if (lastWasHeadline)
{
// split the remainder of the block into a new block
block newBlock;
newBlock.type = blockType::text;
for (int k = curBlock->paragraphs.size() - 1; k > j; k--)
{
newBlock.paragraphs.insert(newBlock.paragraphs.begin(), curBlock->paragraphs[k]);
curBlock->removeParagraph(k);
}
//!!!!!!!!!!!!!!!!!!ERROR!!!!!!!!!!!!!!!!!!
//Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object
thisDoc->addBlock(newBlock);
//!!!!!!!!!!!!!!!!!!ERROR!!!!!!!!!!!!!!!!!!
}
lastWasHeadline = false;
}
}
}
}
From the class header (to show you what my struct declarations look like):
__nogc struct block
{
rectangle bounds;
rectangle adjacent;
rectangle gutterDist;
int type;
vector<paragraph> paragraphs;
block()
{
bounds.left = bounds.right = bounds.top = bounds.bottom = 0;
adjacent.left = adjacent.right = adjacent.top = adjacent.bottom = -1;
gutterDist.left = gutterDist.right = gutterDist.top = gutterDist.bottom = 2147483647;
type = blockType::undecided;
paragraphs.clear();
}
~block() {paragraphs.clear();}
void addParagraph(paragraph newParagraph)
{
// if this is the first line to be added to the paragraph
if (paragraphs.size() == 0)
{
bounds.left = newParagraph.bounds.left;
bounds.right = newParagraph.bounds.right;
bounds.top = newParagraph.bounds.top;
bounds.bottom = newParagraph.bounds.bottom;
}
else
{
if (newParagraph.bounds.left < bounds.left)
bounds.left = newParagraph.bounds.left;
if (newParagraph.bounds.right > bounds.right)
bounds.right = newParagraph.bounds.right;
if (newParagraph.bounds.top < bounds.top)
bounds.top = newParagraph.bounds.top;
if (newParagraph.bounds.bottom > bounds.bottom)
bounds.bottom = newParagraph.bounds.bottom;
}
paragraphs.push_back(newParagraph);
}
void removeParagraph(int index)
{
paragraphs.erase(paragraphs.begin() + index);
}
};
__nogc struct page
{
int width, height, resolution;
vector<block> blocks;
double avgLineHeight; // calculated in reFormat(...)
page()
{
width = height = resolution = 0;
blocks.clear();
}
~page() {blocks.clear();}
void addBlock(block newBlock) {blocks.push_back(newBlock);}
void removeBlock(int index)
{
blocks.erase(blocks.begin() + index);
}
};
// all necessary internal variables
page __nogc* thisDoc;
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Hi,
I am trying to access some methods from user defined class it doesnt allow me to do, it says SetValue() is not a member of Class1
Here is the code
Class1 *obj = new Class1 () ;
obj->SetValue ();
Do I need to set any properties specifically to access this method.
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Are you using pure native C++ ? If yes, your question is in the wrong forum (this forum is for managed C++).
For your problem, did you check if this method was in the class and if you didn't misspelled it ?
Post the header of the class, it can be usefull.
Cédric Moonen
Software developer
Charting control
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Hi,
when using Clipboard.SetDataObject()in my source code, I got the error 'Clipboard': undeclared identifier.
If I add the lines below,
using namespace System::Reflection;
Clipboard = new Clipboard();
Clipboard.SetDataObject(...);
I got 'System is not a class or namespace name' and other errors.
Any advise???
Thank you in advance
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You need to reference System.Windows.Forms.dll and "using namespace System::Windows::Forms". Also, make sure you have a "using namespace System" in your code.
-- modified at 15:35 Tuesday 23rd May, 2006
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Hi Jackson,
Thank you for your answer.
Actually I was compiling my src code using .Net 2003. When I added the lines-
using namespace System::Windows::Forms;
using namespace System;
I got other compiling errors C2653, which says 'System is not a class or namespace name.
To reference System.Windows.Forms.dll, I just need to specify its path correctly, right?
Robert
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Unless your GAC is messed up, you can have the following place before any actual code:
#using <mscorlib.dll>
#using <System.Windows.Forms.dll>
using namespace System;
using namespace System::Windows::Forms;
Geo
-- modified at 9:15 Wednesday 24th May, 2006
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I am writing a game using Visual C++ (Windows Forms Applications). But I find some difficulty in playing music while the game is started.
Could anybody answer me which function should I use and how to ?? 
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Whats wrong with the following, actually my VC++.Net application is not calling MFC ActiveX method it says "Object Reference Error", i can able to compile successfully.
System::Byte abData[] = new System::Byte[nLength];
brFileContent->Read (abData,0,2); //brFileContent is Binary Reader
Byte *pbManagedData = &(abData[0]); // Get starting point of Array (I can able to see Data and address here
axSimpleAdditionAtx1 ->FinalBy (pbManagedData); // Calling Activex
+++++++++++++++++++++++
Method signature in ActiveX which is not getting called..
void VRMControl::FinalBy (BYTE* ByteValue, LONG Length) // Prototype
{
}
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Hi,
I am using following code to read the file and put it in memory in VC++.
brFileContent->Read (abData,0,length); // Reading Bytes
Byte __pin *pbManagedData = &(abData[0]); // Get starting point of Array
axSimpleAdditionAtx1 ->SendBy(pbManagedData,3); // Send it to MFC AX
I need to read this memory pointer in MFC ActiveX how can do it; I am using following method to receive the pointer and length from Application
void VRMControl::SendBy(BYTE* ByteValue, LONG Length)
{
AFX_MANAGE_STATE(AfxGetStaticModuleState());
// TODO: Add your dispatch handler code here
}
From the ByteValue variable i want to read my data; please help me out.
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I am trying to create something along the lines this type of C++ code:
Point* myPoints = new Point[200];
I have C++ code which contains a series of points and I would like to convert them to System::Drawing::Point. I can get a single point to work:
System::Drawing::Point* thePoints = __nogc new System::Drawing::Point(1,2);
but am unable to compile when using an array of points. I have tried several different iterations using the following line of code. I've tried various versions of __gc and __nogc. I've tried System::Drawing::Point[] instead of '*'.
System::Drawing::Point* thePoints = new System::Drawing::Point[200];
Any help will be greatly appreciated. Other parts of my code work. I am able to display my C# Form from C++ just fine.
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Try this:
Point* myPoints[] = new Point*[200];
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Thanks for the idea. I got the following compiler error:
error C3159: 'Point' : array of pointers to value type cannot be declared
But your advice led me to the right answer. This worked:
System::Drawing::Point thePoints[] = new System::Drawing::Point[200];
As a result, I am now able to create my set of points in C++ and then have my C# Form aware of these as shown below. The method LookAtThePoints is simply a way I can quickly look at the point data and be sure what I created was successful in the C# Form.
<br />
System::Drawing::Point thePoints[] = new System::Drawing::Point[200];<br />
for (int i = 0; i < 200; i++)<br />
{<br />
thePoints[i] = System::Drawing::Point(i, i);<br />
}<br />
SimplePanel::Form1* theForm = new SimplePanel::Form1();<br />
theForm->rawPoints = thePoints;<br />
theForm->LookAtThePoints();<br />
I am doing this because we currently have an MFC application which converts laser data to 2D/GDI points. I want to start using C# Forms, so I am looking at ways I can begin creating new Views/Windows with C# and maintain our MFC app.
Thanks again for the help. It got me on the right path.
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I need to override 'virtual void Dispose(bool disposing)' in a class packed in library that I can't recompile, just to prevent it from clearing some resources, however I can't seem to find a way to do it in C++/CLI. I get the 'error C2605: 'Dispose' : this method is reserved within a managed class'.
I'm currently using C# wrapper .dll just to solve this - 'virtual override void Dispose(bool disposing) {}' - and consume it from my C++/CLI project, but there must be a better way?
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In C++/CLI, the dispose pattern is:
ref class Base
{
public:
Base(void)
{
}
~Base(void)
{
// Release managed resources
this->!Base();
}
protected:
!Base(void)
{
// Release unmanaged resources
}
};
So, the methods Dispose() and Dispose(bool disposing) aren't available at compile-time. Also, I believe you cannot override a virtual dtor!
-- modified at 21:45 Saturday 20th May, 2006
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If you're doing somthing like the following in C#:
public class test
{
protected override void Dispose(bool disposing)
{
if (disposing)
{
// do A
}
// do B
}
}
Then the C++/CLI equivalent is this:
public ref class test
{
public:
~test()
{
DisposeObject(true);
}
private protected:
!test()
{
DisposeObject(false);
}
private:
void DisposeObject(bool disposing)
{
if (disposing)
{
// do A
}
// do B
}
};
Our Instant C++ C# to C++ converter maintains the original 'Dispose' method, but renames it and makes it private - called only from the new CLI destructor and finalizer. This is to make conversion easier to understand, but you could dispense with the Dispose altogether and code that logic within the destructor and finalizer directly.
David Anton
www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
Instant C++: C# to C++ converter and VB to C++ converter
Instant J#: VB to J# converter
Clear VB: Cleans up VB.NET code
Clear C#: Cleans up C# code
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Thanks for the answers, but it doesn't exactly solve my problem:
If you take the 'test' class you specified and compile it as a C# lib .dll, and then inherit it in the C++/CLI project, how do you override the original 'test::Dispose(bool disposing)'?
It looks like there's no way to do it from C++/CLI? From the C#, you just override it.
I guess that in pure C++ something like that would not be possible at all - overriding the virtual method called from parent's destructor will still cause call to the original parent's method (or maybe compile-time error or something like that, depending on the complier)?
But I guessed that since it's possible in C#, it should be possible in C++/CLI, am I wrong somewhere? 
For example, if you want to force BinaryWriter/Reader not to close the underlying stream when it's disposed, how would you do it from C++/CLI?
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Filip Strugar wrote: But I guessed that since it's possible in C#, it should be possible in C++/CLI, am I wrong somewhere?
C# and C++/CLI are distinct languages. You can write whole ASP.NET applications with C# but not with C++/CLI. You can embedded unmanaged code in C++/CLI but not with C#.
I don't think you can override the dispose pattern in C++/CLI due to the employment of deterministic finalization in managed code.
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Yes - after doing some research on this, it appears that it's not even possible to override the original Dispose(bool) method for a base class, due to 'Dispose' being reserved.
It's strange that this is not allowed. Even a C# class derived from a C++/CLI base class will allow overriding the implicit Dispose(bool) method generated internally by the C++/CLI class having a destructor (since a C++/CLI class will implicitly implement the IDisposable interface when containing a destructor).
If anyone knows of a way to do this (or a reason it cannot be allowed), I'd be very interested.
David Anton
www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
Instant C++: C# to C++ converter and VB to C++ converter
Instant J#: VB to J# converter
Clear VB: Cleans up VB.NET code
Clear C#: Cleans up C# code
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I have several static libraries in native c++. I am working on a new project that will use these libraries. Since this is a new project I was thinking of using C++/CLI for creating GUI using WinForms and use functionality from native static libraries. So I created a new Windows Form Application and declared an instance of a class defined [from one of the library] in the Form1.h file. It builds fine but gives a runtime exception. Then I compiled that library with /clr switch and now application runs fine.
So my question is if I want to use native static libraries from c++/cli, should I recompile all libraries with /clr switch? Or am I missing something very obvious.
thanks
-Saurabh
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What is the runtime exception? Who is throwing it?
You should not need to rebuild all your static libraries with /clr. You only need the /clr switch for the interop files - those the bridge the native and the managed world.
gmileka
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While I'm posting possible problems I've found...
When a struct (or class for that matter) with an Int32 ^ is deserialized an exception is thrown.
Again: Is this a "feature" that I just haven't seen documented anywhere, or an actual issue?
----CODE----
using namespace System;
using namespace System::IO;
using namespace System::Runtime::Serialization::Formatters::Binary;
[Serializable]
public ref struct TestStruct {
Int32^ i;
};
[Serializable]
public ref struct TestStruct2 {
int i;
};
int main(array<System::String ^> ^args)
{
//MemoryStream to do use for serializing
MemoryStream^ ms = gcnew MemoryStream();
//Binary Format
BinaryFormatter^ bf = gcnew BinaryFormatter();
//Create the structure
TestStruct ^t = gcnew TestStruct();
//Initialize the data
t->i = 42;
//Serialize the string
bf->Serialize(ms,t);
//GO back to the beginning of the stream to deserialize
ms->Seek(0,SeekOrigin::Begin);
try {
Object^ o = bf->Deserialize(ms);
System::Console::WriteLine("o is {0}",o);
} catch(System::Runtime::Serialization::SerializationException^ e) {
System::Console::WriteLine("Caught an exception while trying to deserialize TestStruct!");
System::Console::WriteLine(e->Message);
}
/* Generates Exception:
Type: System.Runtime.Serialization.SerializationException
Additional information: Binary stream '42' does not contain a valid
BinaryHeader. Possible causes are invalid stream or object version
change between serialization and deserialization.
Note the 42. If t->i is set to a different value, this changes.
*/
//Reset for second test
ms = gcnew MemoryStream();
bf = gcnew BinaryFormatter();
TestStruct2 ^t2 = gcnew TestStruct2();
t2->i = 42;
bf->Serialize(ms,t2);
ms->Seek(0,SeekOrigin::Begin);
try {
Object^ o = bf->Deserialize(ms);
System::Console::WriteLine("o is {0}",o);
} catch(System::Runtime::Serialization::SerializationException^ e) {
System::Console::WriteLine("Caught an exception while trying to deserialize TestStruct2!");
System::Console::WriteLine(e->Message);
}
/* No Exception Generated */
return 0;
}
----CODE END----
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I think you need to change the defintion of TestStruct i from
Int32^ i;
to
Int32 i;
for this to work.
gmileka
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