Before didn't use safe array,
This is a VB docking do Com interface, memory block has been taken to//now traverse each element of the structure, but not how to read, they still hope everybody to give directions, never had this experience


PosLogInfo=the packed record
ReadMark: Byte;
CardNo: Double;
SFType: Smallint;
SFMealTypeID: Smallint;
SFAmount: Double;
CardBalance: Double;
SFDate: TDateTime;
CardUseTimes: Integer;
SFOpterNo: Smallint;
OrderDate: TDateTime;
ProductID: array [0.. 9] of Integer;
ProductNum: array [0.. 9] of Integer;
end;

function SafeArrayToText (p: PSafeArray) : string;
Var

RBound: TVarArrayBound;
I, UCount: Integer;
Xfinfo: PosLogInfo;//record consumption structure

The begin

VarResultCheck ((SafeArrayGetLBound (p, 1, RBound LowBound)));
VarResultCheck (SafeArrayGetUBound (p, 1, UCount));
RBound. ElementCount:=UCount - RBound. LowBound;

//the number of elements, not wrong, in line with the interface prompt 22.

//now traverse each element of the structure, but not how to read, they still hope everybody to give directions, never had this experience
For I:=RBound. LowBound to RBound. ElementCount do
The begin
FillChar (xfinfo, SizeOf (xfinfo), 0).
//that don't know how to write, arguably is right, but I don't know what's going on, read the value is always wrong, and each is the same actually
VarResultCheck (SafeArrayGetElement (p, I, xfinfo));

Memo1. Lines. The Add (" CardNo: "+ FloatToStr (xfinfo. CardNo));
Memo1. Lines. The Add (' SFType: + FloatToStr (xfinfo. SFType));
Memo1. Lines. The Add (' SFAmount: + FloatToStr (xfinfo. SFAmount));
Memo1. Lines. The Add (' CardBalance: + FloatToStr (xfinfo. CardBalance));
Memo1. Lines. The Add (+ formatdatetime 'SFDate:' (' ', xfinfo. SFDate));

end;
end;

//FillChar has clear 0 structure, traverse value is the same, all specifications should already have the assignment, but also not

CardNo: 0
SFType: 5120
3.79442416006077 e-321 SFAmount:
6.21476085095821 e-317 CardBalance:
SFDate: 1899-12-30

CardNo: 0
SFType: 5120
3.79442416006077 e-321 SFAmount:
6.21476085095821 e-317 CardBalance:
SFDate: 1899-12-30

CardNo: 0
SFType: 5120
3.79442416006077 e-321 SFAmount:
6.21476085095821 e-317 CardBalance:
SFDate: 1899-12-30

CardNo: 0
SFType: 5120
3.79442416006077 e-321 SFAmount:
6.21476085095821 e-317 CardBalance:
SFDate: 1899-12-30

CodePudding user response:

SafeArrayGetElement (p, I, xfinfo); What's p
SafeArrayGetElement (target array, the array indexing number, read the count of group)

CodePudding user response:

reference 1st floor sololie response:

SafeArrayGetElement (p, I, xfinfo); What's p
SafeArrayGetElement (target array, the array indexing number, read the count of group)

P: PSafeArray, is a safe array


Hello, my friend also say so, the return value should be a array, how should I keep this array into my record of consumption structure?
SafeArrayGetElement (target array, the array indexing number, read the count of group)

CodePudding user response:

Try

 
Var 
RBound: TVarArrayBound; 
I, UCount: Integer; 
XfinfoArr: an array of PosLogInfo; 
The begin 
VarResultCheck ((SafeArrayGetLBound (p, 1, RBound LowBound))); 
VarResultCheck (SafeArrayGetUBound (p, 1, UCount)); 
RBound. ElementCount:=UCount - RBound. LowBound; 

SetLength (xfinfoArr, SizeOf (PosLogInfo) * 22); 
For I:=RBound. LowBound to RBound. ElementCount do 
The begin 
//FillChar (xfinfo, SizeOf (xfinfo), 0). 
VarResultCheck (SafeArrayGetElement (p, I, xfinfoArr)); 

Memo1. Lines. The Add (" CardNo: "+ FloatToStr (xfinfoArr [I]. CardNo)); 
Memo1. Lines. The Add (' SFType: + FloatToStr (xfinfoArr [I] SFType)); 
Memo1. Lines. The Add (' SFAmount: + FloatToStr (xfinfoArr [I] SFAmount)); 
Memo1. Lines. The Add (' CardBalance: + FloatToStr (xfinfoArr [I] CardBalance)); 
Memo1. Lines. The Add (+ formatdatetime 'SFDate:' (' ', xfinfoArr [I] SFDate)); 
end; 
end; 

CodePudding user response:

Don't know how your safearray is stored, this is an example, the deposit is two hexadecimal array data, put it out of the code:
The class procedure Convert. SafeArrayToBytes (const AData: OleVariant;
Var ABytes: TBytes);
Var
Sa: PSafeArray;
L, u: Integer;
P: Pointer;
The begin
SetLength (ABytes, 0);
If (TVarData (AData.) VType=VT_ARRAY or VT_UI1) then
The begin
Sa:=TVarData (AData). VAny;

If S_OK & lt;> SafeArrayGetLBound (sa, 1, l) then the Exit;
If S_OK & lt;> SafeArrayGetUBound (sa, 1, u) then the Exit;
If (u=0) then
The Exit;
Then the if S_OK=SafeArrayAccessData (sa, p)
Try
SetLength (ABytes, u - l + 1);
CopyMemory (@ ABytes [0], p, u - l + 1);
The finally
SafeArrayUnaccessData (sa);
end;
end;
end;