How can I assign a value to a Olevariant variable which comes from a TStream?

Question

I need to read from a Stream and put the buffer that was read in a OleVariant (VarArray) variable.

var
MemoryStream : TMemoryStream;
Data : OleVariant;
begin
            MemoryStream:=TMemoryStream.Create;
            try
                FuncFill(MemoryStream); //Filling the stream
                MemoryStream.Seek(0,0);
                MemoryStream.Read(Data, MemoryStream.Size);//this line lock the app, I need allocate the memory for the OleVariant variable?
            finally
             MemoryStream.Free;
            end;

end;

How I can assign the read value from the TMemoryStream to a olevariant variable?

I'm using delphi 5.

Answer 1

You can use the VarArrayLock function to get a pointer to the OleVariant data and then read to this pointer.

check this code wich use a VarArray of varByte elements.

var
 MemoryStream : TMemoryStream;
 Data : OleVariant;
 DataPtr : Pointer;
begin
   MemoryStream:=TMemoryStream.Create;
     try
      FuncFill(MemoryStream); //Filling the stream
      MemoryStream.Seek(0,0);
          Data    :=VarArrayCreate([0, MemoryStream.Size - 1], varByte);
      DataPtr     :=VarArrayLock(Data);
       try
         MemoryStream.ReadBuffer(DataPtr^,MemoryStream.Size); //Get the pointer to the variant variable.
       finally
         VarArrayUnlock(Data); //when you are done , you must call to VarArrayUnlock
       end;
    finally
      MemoryStream.Free;
    end;    
end;