Re: [amibroker] Passing string via AmiVar

["Tomasz Janeczko" <groups@xxxxxxxxxxxxx>]

Hello,

AmiVar is an UNION, you must assign only ONE field.
If you are assigning value to string you MUST NOT assign value to .val member
of an union.

AmiVar var;
var.type = VAR_STRING;
var.string = (char*)resultsym[11];
var.val = EMPTY_VAL;  /// WRONG !!! REMOVE THIS !

http://msdn.microsoft.com/en-us/library/y9zewe0d(VS.80).aspx

Also you must NOT return char arrays created on stack because they will
disappear when function goes out of scope. You must use gSite.Alloc() to allocate
memory dynamically and use this memory to write the string to.


Best regards,
Tomasz Janeczko
amibroker.com
----- Original Message ----- 
From: "markedme9" <markedme9@xxxxxxxxx>
To: <amibroker@xxxxxxxxxxxxxxx>
Sent: Sunday, August 30, 2009 10:51 PM
Subject: [amibroker] Passing string via AmiVar


> Hi, 
> 
> I am having trouble with passing strings. 
> I get access violation error. 
> 
> AmiVar AlterSymbol( int NumArgs, AmiVar *ArgsTable )
>  {
> AmiVar var;
> var.type = VAR_STRING;
> var.string = (char*)resultsym[11];
> var.val =  EMPTY_VAL;
> return var;
>  }
> 
> "AlterSymbol", { AlterSymbol, 0, 0, 0, 0, NULL } 
> 
> In AFL fomula it is called as
> AlterSymbol ();
> 
> 
> I dont get access violation error when I pass a string directly 
> var.string = "some text";
> 
> 
> Is this the right way to do it?
> 
> 
> Thanks
> 
> 
> 
> ------------------------------------
> 
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> 
> 


------------------------------------

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