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Actually, it's simple: The things you only want to see in debug mode should use Debug, the others Trace. If you use a library like log4net[^] then you can also differentiate between Debug, Info, Warning, Error and different output formats like file, e-mail, syslog etc., which is more suited for real production message logging.
regards
modified 12-Sep-18 21:01pm.
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Hi all, i didn't know which forum to post this on, so i hope this is the right one
(i know i wrote a lot of stuff here, if you should be to lazy to read all of this, i understand  , but please read the last codeblock)
I am making a program in c# which detects usb devices and does stuff with the info i collect. I don't have a lot of experience with the usb stuff, so i have googled a lot of info together. Most of my code i wrote i translated from a c++ program. But my knowledge of c++ is minimum.
The problem is that i'm not able to translate a certain line of code to c#
in c++ i have something like this (i just copied a small piece but i think you get the idea)
typedef struct DEV_BROADCAST_DEVICEINTERFACE {
DWORD dbcc_size;
DWORD dbcc_devicetype;
DWORD dbcc_reserved;
GUID dbcc_classguid;
char dbcc_name[1];
}
struct DEV_BROADCAST_HDR {
DWORD dbch_size;
DWORD dbch_devicetype;
DWORD dbch_reserved;
};
PDEV_BROADCAST_HDR pHdr = (PDEV_BROADCAST_HDR)lParam;
PDEV_BROADCAST_DEVICEINTERFACE pDevInf;
pDevInf = (PDEV_BROADCAST_DEVICEINTERFACE)pHdr;
and in c# i have the following pieces of code
[StructLayout(LayoutKind.Sequential)]
public struct DEV_BROADCAST_HDR
{
public int dbcc_size;
public int dbcc_devicetype;
public int dbcc_reserved;
}
[StructLayout(LayoutKind.Sequential)]
public struct
DEV_BROADCAST_DEVICEINTERFACE
{
public int dbcc_size;
public int dbcc_devicetype;
public int dbcc_reserved;
public Guid dbcc_classguid;
public short dbcc_name;
}
DEV_BROADCAST_HDR pHDR = (DEV_BROADCAST_HDR)Marshal.PtrToStructure(msg.LParam, typeof(DEV_BROADCAST_HDR));
DEV_BROADCAST_DEVICEINTERFACE pDevInf;
now basicly i just want to translate THIS LINE from c++ to c#
pDevInf = (PDEV_BROADCAST_DEVICEINTERFACE)pHdr;
note: i have no idea what i'm doing, but i will be very happy if someone can give me a clue on how to translate this single line of code to c#
thanks in advance
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I think this should work:
pDevInf = (PDEV_BROADCAST_DEVICEINTERFACE)Marshal.PtrToStructure(msg.LParam, typeof(PDEV_BROADCAST_DEVICEINTERFACE)); It seems to me that the second struct is merely part of the first one. It's probably just a way of "viewing" the data in memory.
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thanks for the quick reply
this does indeed work, but when comparing the results from the c++ program with my c# program, a few parameters (like the dbcc size) have different values.. (maybe i just screwed up the rest of my code  )
But to my knowledge i don't need these parameters, and i have the information i need from my usb devices, so i think my problems are solved (for now  )
thanks again
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Glad it worked.
I just noticed that you're defining dbcc_name in C# to be short, even though it's char in C++. This probably means that you may access memory that you shouldn't, and might cause you an access violation. I think the most accurate representation in C# would be sbyte.
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Depends on whether you have to move the class/object around as an argument. If so, use a class.
Otherwise, it doesn't really matter technically, the two DateTimes will live equally happy on the heap or on the stack. But normally, structs are expected to be read-only data containers without behaviour (i.e. they should have no methods except c'tors, the 3 object-inherited methods, and operator-like methods like e.g. Compare). What you have in mind sounds more like a service, so I think a class would be the better choice.
Regards
Thomas
www.thomas-weller.de
Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.
Programmer - an organism that turns coffee into software.
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if you consider using anything else but value types , then use a class. If not, you're free to use a struct
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Jan Sommer wrote: if you consider using anything else but value types
Why should this make any difference? Can you explain that?
The struct/class may live on the stack/heap. In any case, it will contain its fields, so they will consequently live on the stack/heap as well. It is therefore absolutely irrelevant if they were values or refs.
Regards
Thomas
www.thomas-weller.de
Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.
Programmer - an organism that turns coffee into software.
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Boxing occurs if you use reference types in structs.. also, if he only plans to use value types it doesn't allocate as much memory then classes... see http://msdn.microsoft.com/en-us/library/ah19swz4(VS.71).aspx for details
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Jan Sommer wrote: Boxing occurs if you use reference types in structs..
Ummm, what? No! This would mean that whole graphs of classes would be copied from the heap to the stack eventuallly when referenced by a struct  .
See here: http://en.csharp-online.net/Classes,_Structs,_and_Objects—When_Boxing_Occurs[^]
Jan Sommer wrote: also, if he only plans to use value types it doesn't allocate as much memory then classes
This is also wrong as soon as there is more than one reference to the class/struct.
Regards
Thomas
www.thomas-weller.de
Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.
Programmer - an organism that turns coffee into software.
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Another minor difference: A struct is accessed by a pointer to its start in memory, but a class is accessed by a pointer to a pointer to its start. So if you're repeatedly accessing this object and you want the maximum efficiency, a struct will save one memory read per access.
As was pointed out earlier, a struct is less efficient to pass as a parameter because the whole object is pushed onto the stack. A class only has its reference (an address) put on the stack, so is faster to pass.
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Alan Balkany wrote: As was pointed out earlier, a struct is less efficient to pass as a parameter because the whole object is pushed onto the stack. A class only has its reference (an address) put on the stack, so is faster to pass.
If the struct is small enough, it can be copied with a single instruction, making it just as efficient as copying a reference. It's recommended that a struct should not be larger than 16 bytes, so that it can be copied with a few instructions, without using a loop.
Despite everything, the person most likely to be fooling you next is yourself.
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Unless you have a special reason to make a struct, make it a class.
Classes are easy to implement, just put a few properties in it and it works without problems. A struct needs more work and more knowledge to be implemented properly, or you may end up with a struct that does unexpected things.
Despite everything, the person most likely to be fooling you next is yourself.
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If you think of it as a value, make it a struct.
If having operators for it makes sense, you're likely thinking of it as a value.
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I have a form with 3 tab pages. On the first tab I have text and drop down boxes. Some boxes you insert data, some are bound to database tables that you pick items and customers from. I want to save all this info to a separate table in the same database as a new entry. My problem is I don't know how. If I was to use a datagrid and just change the info and save it back to the same table that I can do. But to move it all to a different table thats the tickler. Any help would be great.
Thanks Don
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1) Make a stored procedure in the database to insert the row(s)
2) Make a SqlCommand object in code with CommandText set to the name of the stored procedure
3) Fill the command object's Parameters collection with the values from the form for the stored procedure
4) Call the command object's ExecuteNonQuery() function
Viola!
Keep It Simple Stupid! (KISS)
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Hello everyone,
I have some phone to each user and I want to store all photos into memory with key-value pair. Key is the user name and value is the binary photo stream. Any ideas how to store binary photo content into memory? Which data structure is suitable to be used?
thanks in advance,
George
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You can store images in byte[] or MemoRyStream.
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Cool, Giorgi!
1.
And if total image size is large than physical memory size, Dictonary will automatically use Windows vistual memory? There is no size limitation for Dictionary data structure itself?
2.
How to read the full content of a binary file into byte[] or MemoRyStream? Confused. ??
regards,
George
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You can use Binary Serialization to write an instance of Image class to memorystream. You can call ToArray() method of memoryclass to copy memorystream data to byte[]. You can also use BinaryReader to read file content in byte[].
Not sure about first question.
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Thanks Giorgi,
1.
I am interested in "Binary Serialization to write an instance of Image class to memorystream". Could you show me some pseudo code or recommend me some samples please?
2.
If I read image into memorystream, then the whole image will be in memory? My confusion is for object stored in memorystream as you suggested solution, will all content be hold in memory or just a handle hold in memory which points to the physical image file? 
regards,
George
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George_George wrote: And if total image size is large than physical memory size
Then you shouldn't be storing it in memory.
George_George wrote: How to read the full content of a binary file into byte[] or MemoRyStream
As always, and as you've been told an obscene number of times, you read the bloody docs[^] and/or search for relevant examples[^]!
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Thanks J4amieC,
1.
Could Dictionary use virtual memory?
2.
I read a couple of samples, but either for VB or for ASP.Net, which is not my needs. My purpose is simple, just write a console application is fine. And I do not care about the content of image, so I do not care whether use Image class or not. (the samples all use image class)
I read MSDN sample but seems not describing the same problem for me.
Are there an easy to use sample which just convert image file into memory stream or byte[]?
regards,
George
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As far as I know, when you exceed physical memory, the OS will automatically start to use virtual memory. Your program won't know the difference; it will just start to slow down when you're accessing "memory" pages that have been written to disk.
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