Managed C++/CLI

James T. Johnson8-Jun-02 10:38

James T. Johnson

8-Jun-02 10:38

Create a property called Item which takes a common parameter in both its set/get functions. ie

__property System::String* get_Item(int index)
{ 
  ....
}
 
__property void set_Item(int index, System::String* value)
{
  ....
}

I don't see anything that lets you create a C# indexer were the class instance can be treated as an array; I assume if you use the Item property name it allows C# to use it as if it were one.

HTH,

James

Michael Mac8-Jun-02 11:14

8-Jun-02 11:14

I don't work.

C++ function disassembly is

.method public specialname instance string 
        get_Item(int32 index) cil managed

and C# is

.method public hidebysig specialname instance string 
        get_Item(int32 index) cil managed

Mayby it's possible to write this function in CLR?

James T. Johnson8-Jun-02 15:14

James T. Johnson

8-Jun-02 15:14

It appears Indexers created in MC++ only work in MC++ AND you can't create an indexer that operates on a class instance.

I'll look into it more after the hockey game Smile | :)

James

Michael Mac8-Jun-02 21:03

A problem with serializtion

8-Jun-02 21:03

I'll appreciate it. Smile | :)

Thanks

Michael Mac8-Jun-02 1:33

8-Jun-02 1:33

I want to serialize using xml a class which contains a IPEndPoint field. I can't get it to work. Does anybody know what to do? But I don't want to use other formatter. Help!!! Please. Cry | :((

public class __gc Message
{
public:
   __property Byte get_ByteMessage ( )[] { return m_byteMessage; }
   __property void set_ByteMessage ( Byte byteMessage[] ) { m_byteMessage = byteMessage; }
   __property IPEndPoint* get_Sender ( ) { return m_ipeEndPoint; }
private:
   Byte m_byteMessage[];   
   IPEndPoint* m_ipeEndPoint;
}

Nish Nishant8-Jun-02 1:51

8-Jun-02 1:51

Is IPEndPoint a serializable class? If not it won;t get serialized. Not automatically. Not sure of this, but if you can derive another class from IPEndPoint, and then add the serialization stuff, it just might work. Not very sure about it though, as I already said Smile | :)

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Buy it, read it and admire me Smile | :)

Michael Mac8-Jun-02 2:12

8-Jun-02 2:12

IPEndPoint is a serializable class. In addition, I can't even serialize IPEndPoint itself using xml of course.

m_xmlsSerializer = new XmlSerializer( __typeof ( IPEndPoint) );
// an error with message "There was an error reflecting 'System.Net.IPEndPoint'.

Any other ideas?
Cry | :((

Rama Krishna Vavilala13-Jun-02 12:58

Rama Krishna Vavilala

13-Jun-02 12:58

Michael Mac wrote:
I can't even serialize IPEndPoint itself using xml of course.

Does it have a public constructor? The exception normally gives the detail reason of what is missing from the class

Michael Mac13-Jun-02 22:04

13-Jun-02 22:04

The code shown below

XmlSerializer* xml = new XmlSerializer ( __typeof( IPEndPoint ) );

returns an exception with the message: "There was an error reflecting 'System.Net.IPEndPoint'".
So I think it's impossible to serialize IPEndPoint class using XML. The alternatives are BinaryFormatter and SoapFormatter.

43 68 65 65 72 73 2c
4d 69 63 68 61 65 6c

Mixing managed and unmanaged code

James T. Johnson13-Jun-02 22:13

James T. Johnson

13-Jun-02 22:13

Correct; unfortunately MS didn't document this topic very well. The XmlSerializer doesn't use any of the other serialization stuff, no Serializable attribute nor ISerializable; I think its a shame myself.

The XmlSerializer works by using the reflection.emit classes to construct a class that will place all the public fields/property's in an XML document; when it deserializes it tries to access the nodes in the document as the field/property name to place the value back in. When it does this it creates an instance of the object using the default constructor.

It DOES let you control some functionality by using Attributes and the OverrideAttributes class; but I don't like that solution very well.

James

Alexandru Savescu6-Jun-02 0:58

6-Jun-02 0:58

Suppose I have an old application with unmanaged code and I adding some .NET classes that are of course managed.
The question is: Will my unmanaged code be compiled as native code and the managed code will be CLR metadata? I am asking this, because I want my old, unmanaged part of application to be very fast, not a MSIL that is at first run (?) compiled into native code.

Best regards,
Alexandru Savescu

Nish Nishant6-Jun-02 1:38

6-Jun-02 1:38

Use #pragma unmanaged to specify that the following code is to be compiled to native code and #pragma managed when you end the native stuff

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Buy it, read it and admire me Smile | :)

Alexandru Savescu7-Jun-02 10:00

7-Jun-02 10:00

Thanks Nish!

However what if I want to declare a managed type inside of an existing class? Will then my whole class be managed? (This is something that I would not like Smile | :)

)

Best regards,
Alexandru Savescu

Nish Nishant7-Jun-02 14:07

7-Jun-02 14:07

Alexpro wrote:
Will then my whole class be managed? (This is something that I would not like )

No. If you want to use a managed type inside say your CDialog class, then you'll have to only add #pragma managed for the function in the class, where you use the managed type. That was how it was in Beta 2. I didn't chk to see if it allows you to have a managed line of code inside an unmanaged marked function. I should think not!

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Buy it, read it and admire me Smile | :)

Alexandru Savescu7-Jun-02 21:48

7-Jun-02 21:48

Nish - Native CPian wrote:
if it allows you to have a managed line of code inside an unmanaged marked function. I should think not!

It doesn't!

Best regards,
Alexandru Savescu

Nish Nishant7-Jun-02 21:45

7-Jun-02 21:45

Alexpro wrote:
It doesn't!

Well, at least, they granularised at the function level instead of at the class level which would have been horrible.

Nish Smile | :)

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Buy it, read it and admire me Smile | :)

Fatest Way Around

Sidney5-Jun-02 15:33

5-Jun-02 15:33

Hi everyone,

I need advice regardin my problem, here's my problem:

I have a Text File(serves as my database) with 3 colums fixed length, example

Name Address Age
AAA 123 Anywhere 12
BBB .... ...
Joseph 345 Somewhere 15
Rosie 098 Cool DC 20

I need to search this Text File, in the real world this Text File migh contain 1 Million records as soon as we populate our database.

My question is... what is the fastest way to search for a particular string in this text file. Note: I only search for the name, If I find the name... I need to get the enrite line and process it.

I will really appreciate any help that you can give me.

Thanks/Regards
Sidney

Alexandru Savescu5-Jun-02 18:01

5-Jun-02 18:01

I will give you a fast, but memeory consuming solution.
Use a std::map to store the name as keys and you make a struct to store the address. Read the whole file and fill the map. Then, when you search the name you will use std::map::find that will do a binary search.
At the end of the program you iterate through the map and write it to the file.

If you have multiple entries with the same name you may consider multimap. Since you post it to the Manage C++ you may also consider hash_map.

Best regards,
Alexandru Savescu

Sidney5-Jun-02 18:22

5-Jun-02 18:22

Thanks Alexandru! I'll see if I can do this, do you have sample code that used STL Map? if you have would you be so kind to share it with me? And by the way just for info... the fields are of Fixed length, example

Field Name Position Length
Fld1 1 10
Fld2 11 21
etc...

Thanks/Regards
Sidney

Alexandru Savescu5-Jun-02 18:22

5-Jun-02 18:22

You can look at the article on CP about STL here. Also you can read MSDN (the one that comes with .NET is nicer than the VC6.0's one), or the SGI documentation.

Best regards,
Alexandru Savescu

Sidney6-Jun-02 9:06

6-Jun-02 9:06

Hi Alexandru,

I get an error in my code when I try to use the multimap, the error is "Cannot open include file: 'multimap' C++" can you help me?

here's my code:

#include <string>
#include <iostream>
#include <multimap>
using namespace std;

struct ltstr
{
bool operator()(const char* s1, const char* s2) const
{
return strcmp(s1, s2) < 0;
}
};

int main()
{
multimap<const char*,="" int,="" ltstr=""> m;

m.insert(pair<const char*="" const,="" int="">("a", 1));
m.insert(pair<const char*="" const,="" int="">("c", 2));
m.insert(pair<const char*="" const,="" int="">("b", 3));
m.insert(pair<const char*="" const,="" int="">("b", 4));
m.insert(pair<const char*="" const,="" int="">("a", 5));
m.insert(pair<const char*="" const,="" int="">("b", 6));

cout << "Number of elements with key a: " << m.count("a") << endl;
cout << "Number of elements with key b: " << m.count("b") << endl;
cout << "Number of elements with key c: " << m.count("c") << endl;

cout << "Elements in m: " << endl;
for (multimap<const char*,="" int,="" ltstr="">::iterator it = m.begin();
it != m.end();
++it)
cout << " [" << (*it).first << ", " << (*it).second << "]" << endl;
}

Thanks/Regards
Sidney

Alexandru Savescu6-Jun-02 9:35

6-Jun-02 9:35

Hello sidney

The < and > tags were stripped by the html parser. Please send the code between <pre> and </pre> so I can see what you include and what include not. However this code sould work

#include <multimap>
using namespace std;
....

Best regards,
Alexandru Savescu

Sidney6-Jun-02 11:04

6-Jun-02 11:04

Here's the code:

#include <string>
#include <iostream>
#include <multimap>
using namespace std;

struct ltstr
{
bool operator()(const char* s1, const char* s2) const
{
return strcmp(s1, s2) < 0;
}
};

int main()
{
multimap<const char*, int, ltstr> m;

m.insert(pair<const char* const, int>("a", 1));
m.insert(pair<const char* const, int>("c", 2));
m.insert(pair<const char* const, int>("b", 3));
m.insert(pair<const char* const, int>("b", 4));
m.insert(pair<const char* const, int>("a", 5));
m.insert(pair<const char* const, int>("b", 6));

cout << "Number of elements with key a: " << m.count("a") << endl;
cout << "Number of elements with key b: " << m.count("b") << endl;
cout << "Number of elements with key c: " << m.count("c") << endl;

cout << "Elements in m: " << endl;
for (multimap<const char*, int, ltstr>::iterator it = m.begin();
it != m.end();
++it)
cout << " [" << (*it).first << ", " << (*it).second << "]" << endl;
}

Thanks/Regards
Sidney

Alexandru Savescu6-Jun-02 19:50