Array of structs

[charlesh3]

I'm an engineer with a C background that is trying to do my first c# project.

I created a struct:
public struct MyStruct {
public static UInt32 bUsed;
public static UInt32 nCFreqHz;
public static UInt32 nDemIdx;
public static UInt32 nDemBWIdx;
public static UInt32 nVBFBWHz;
public static int nVBFFcHz;
public static long aTime;
public static char version;
public static char[] extDC;
public static char [] rsvd;
public static char [] desc;
} }

and then an array of structs with:
MyStruct[] MemoryBank = new MyStruct[100];

My code then does:
MemoryBank[MemoryIndex].bUsed = (r.ReadUInt32());

but the compiler objects with:
'WindowsFormsApplication1.Form1.My Struct.bUsed' cannot be accessed with an instance reference; qualify it with a type name instead

I take this to mean my array of structs is being treated as a class, not an array of structs. I've tried to Google this with no real luck and also tried a few fixes. Could someone educate me?

Thanks -

Chuck

[tlhintoq]

No need for them to be static.

Might I suggest a "less C" and "more C#" way?

public class MyStruct 
{
public UInt32 bUsed; 
public UInt32 nCFreqHz; 
public UInt32 nDemIdx; 
public UInt32 nDemBWIdx; 
public UInt32 nVBFBWHz; 
public int nVBFFcHz; 
public long aTime; // This could probably be a DateTime instead of a long
public char version; 
public char[] extDC; 
public char [] rsvd; 
public char [] desc; 
}
}
 
List<MyStruct> MemoryBank = new List<MyStruct>();
 

By making it a class rather than a struct you gain the capability of including methods inside the class. A class can then have constructor methods with parameters so you can have a lot of your initialization work take place as soon as it is created.

By use a List<> you gain several built-in methods that don't exist in an array such as RemoveAt(int Index). You also don't *have* to declare a size for the list as it will dynamically grow as needed.

[charlesh3]

Thanks for the pointer. The compiler doesn't like your class definition - on the first element (which is bUsed) it tells me "A get or set accessor expected".

And yes, I'd happily convert the struct to a class to make it work. I used a struct only because my data is just a bunch of numbers and I really don't have a need for the elegance of a class. But I have no moral ojection to wasting capabilities in orderto get the show on the road.


Chuck

P.S.

Here's the entire class definition that the compiler objects to:

public Class CUserMem {
public UInt32 bUsed; // supposed to be a Boolean but occupies 4 bytes
public UInt32 nCFreqHz; // Center Frequency
public UInt32 nDemIdx; // demod index: 4 or 5
public UInt32 nDemBWIdx; // normally 3 for 6 kHz
public UInt32 nVBFBWHz; // user selected filter BW (3.63 is a normal choice)
public int nVBFFcHz; // frequency offset of filter
// time_t aTime;
public long aTime; // long (epoch time when memory was created)
public char version; // 0 currently
public char[] extDC; // 3 bytes of external downconverter info
public char [] rsvd; // 4 bytes reserved
public char [] desc; // memory tag
}

[Christian Binder]

@tlhintoq
As far as I know, also structs can have methods and Constructors (except the Standard-Constructor with no params)

The usage of structs could in some situations be quite useful, e.g. if passing the whole thing by value without having to fear, that your passed object would be changed as it could be when passing the object reference ...

But I agree with your opinion, that structs might not be used as often as classes.