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Inerop help

Greetings,

I apologize for re-posting this, but I'm running out of options on my
side.

I've got a DLL that's not COM compatible and I'm stuck using interop
for the first time. I got couple of simple DLL calls all right but
cannot get the most important one to work.

Here is documentation:

---

int LoadSymbol( char*sym, void *data , int max_rec , bool
IGNORE_HOLIDAYS = true , bool RAWDATA = true ,usr_master_def*MasterRec
= 0);

Returns: Number of days loaded. Negative number indicates an error.

Parameters:

sym - Points to the stock symbol to load.

data - Points to an array of type Stock_Record.

max_rec - An integer value...

IGNORE_HOLIDAYS - Boolean value...

RAWDATA - Boolean value...

---

Here is C++ example:

....
char symbol[12];
#define MAX_RECS 10000;
Stock_Record data[MAX_RECS];
....
num = LoadSymbol( symbol , &data[0] , MAX_RECS , FALSE , TRUE , 0 );
....

Here is a definition for Stock_Record struct:

typedef struct
{
char MM;
char DD;
short YY;
float open;
float hi;
float lo;
float cl;
long vol;
char RS;
float oi;

} *LPSTOCK_RECORD, Stock_Record;

I don't know if a definition for Master_Rec is necessary (the last
argument for LoadSymbol function) since they just passed 0 in the
example. Pardon my naivety if it's totally wrong assumption.

Anyway, when I call this function (LoadSymbol) I got a positive number
returned meaning that records have been read. The only problem - they
have no data.

Here is C#:

[DllImport("reader.dll")]
public static extern int LoadSymbol(string symbol, Stock_Record[]
records, int maxDays, bool ignoreHolidays, bool rawData, int
masterRecord);

(I might have screwed up with "int masterRecord" part...). The
following is C# brother of Stock_Record:

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]
public struct Stock_Record
{
public string MM;
public string DD;
public short YY;
public float open;
public float hi;
public float lo;
public float cl;
public long vol;
public string RS;
public float OI;

}

And some execution code:

....
Stock_Record[] records = new Stock_Record[100];
int daysLoaded = LoadSymbol("MSFT", records, 100, false, true, 0);
....

The situation here is that "records" array contains elements with
default values - Stock_Record doesn't get populated.

Any help would be greatly appreciated (I really mean it).

Thank you.

Feb 10 '06 #1
1 1103
ste
Are you sure your c# Stock_Record matches the sizeof() for the c struct
typedef struct // num bytes
{
char MM;
char DD;
short YY;
float open;
float hi;
float lo;
float cl;
long vol;
char RS;
float oi;

} *LPSTOCK_RECORD, Stock_Record;
C' chars are 1 byte and i dont think they map onto C# strings.. which are
probably sizeof( a pointer ) [ a guess ]
Try changing your strings in your mapped record to 'byte' .. eg and make
sure you map the C sizeof(long) to its .net counterpart

The C' short is 2bytes and you should probably use int16 on 32bit machine.


"yuriy_zubarev" <yu***********@yahoo.ca> wrote in message
news:11**********************@o13g2000cwo.googlegr oups.com... Greetings,

I apologize for re-posting this, but I'm running out of options on my
side.

I've got a DLL that's not COM compatible and I'm stuck using interop
for the first time. I got couple of simple DLL calls all right but
cannot get the most important one to work.

Here is documentation:

---

int LoadSymbol( char*sym, void *data , int max_rec , bool
IGNORE_HOLIDAYS = true , bool RAWDATA = true ,usr_master_def*MasterRec
= 0);

Returns: Number of days loaded. Negative number indicates an error.

Parameters:

sym - Points to the stock symbol to load.

data - Points to an array of type Stock_Record.

max_rec - An integer value...

IGNORE_HOLIDAYS - Boolean value...

RAWDATA - Boolean value...

---

Here is C++ example:

...
char symbol[12];
#define MAX_RECS 10000;
Stock_Record data[MAX_RECS];
...
num = LoadSymbol( symbol , &data[0] , MAX_RECS , FALSE , TRUE , 0 );
...

Here is a definition for Stock_Record struct:

typedef struct
{
char MM;
char DD;
short YY;
float open;
float hi;
float lo;
float cl;
long vol;
char RS;
float oi;

} *LPSTOCK_RECORD, Stock_Record;

I don't know if a definition for Master_Rec is necessary (the last
argument for LoadSymbol function) since they just passed 0 in the
example. Pardon my naivety if it's totally wrong assumption.

Anyway, when I call this function (LoadSymbol) I got a positive number
returned meaning that records have been read. The only problem - they
have no data.

Here is C#:

[DllImport("reader.dll")]
public static extern int LoadSymbol(string symbol, Stock_Record[]
records, int maxDays, bool ignoreHolidays, bool rawData, int
masterRecord);

(I might have screwed up with "int masterRecord" part...). The
following is C# brother of Stock_Record:

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]
public struct Stock_Record
{
public string MM;
public string DD;
public short YY;
public float open;
public float hi;
public float lo;
public float cl;
public long vol;
public string RS;
public float OI;

}

And some execution code:

...
Stock_Record[] records = new Stock_Record[100];
int daysLoaded = LoadSymbol("MSFT", records, 100, false, true, 0);
...

The situation here is that "records" array contains elements with
default values - Stock_Record doesn't get populated.

Any help would be greatly appreciated (I really mean it).

Thank you.

---
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Tested on: 10/02/2006 22:32:38
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---
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Virus Database (VPS): 0606-4, 10/02/2006
Tested on: 10/02/2006 22:42:27
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http://www.avast.com

Feb 10 '06 #2

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