Hi Lazarus List and Alvaro,

Below is the reply to this message from my friend Alvaro in Spain, who is a part-time Delphi programmer.

On Tue, Aug 31, 2010 at 6:03 AM, Peter E Williams

Hi Alvaro, forwarded below is another yet to be answered post to the

Lazarus

programmers list. I would appreciate your thoughts on it. The

techniques

dBase code

(in Delphi) to lazarus. I was advised that I should NOT use Dataset.RecNo but instead I should use bookmarks. Can someone

please

[...]

         // here I have the Hexx_Data_DBF file open and begin to loop

through it in a while loop.

                 // here I save the RecNo in a variable

with Hexx_Data_DBF.FieldDefs do Hexx_Data_DBF_RecNo := Dataset.RecNo;

                 // the close the database

close_db; if trace_moves then begin

                     // open a different TDbf file (Trace_File)

open_trace_file; With Trace_File_DBF do try

                       // go to the RecNo of the saved Trace_File's
variable

with Trace_File_DBF.FieldDefs do Dataset.RecNo := (TraceFile_DBF_RecNo);

                       // save the Hexx_Data_DBF's RecNo into the
Trace_File

FieldByName('record_no' ).AsInteger := Hexx_Data_DBF_RecNo;

                     // hmmm.... not sure whether I should be using
finally or except here.

                 // reopen the Hexx_Data_DBF file

open_db;

                 // and the go back to the RecNo saved in the variable

with Hexx_Data_DBF.FieldDefs do Dataset.RecNo := (Hexx_Data_DBF_RecNo); end;

             // then use the Next procedure to continue looping through
the DBF datafile

Hi,

I am working with

Lazarus IDE v0.9.28.2 Beta
MS Windows XP Prof DE sp3
FPC Version 2.2.4

I try do dynmaically load a dll during initialization phase. This can cause exceptions if the dll is not available or
the interface is not matching. Raising an exception at this point causes my application to terminate without any message.

Using "ShowMessage" is not possible. How can I inform the user about the problem before terminating ?

Thanks in advance
Maik

isn't there a way to check that the dll is available before attempting to load it?

i don't know what to possibly do or suggest about the interface not matching...

I've found a solution the works for windows.

//----------------------------------------------
// show a message and terminate the application
//----------------------------------------------
procedure InitError(amsg : AnsiString);
begin
   MessageBox(0,PChar(amsg),'sidex dll error',MB_ICONERROR);
   Halt(1); // terminate application
end;

This works for me now in windows. I need to develop it maybe while porting to Linux and MacOSx.
Only the direct windows API call works here, because the application is not initilized at this point.
A conditional compile to use a writeln for console application might be useful too.