I found a solution to extract the contents of a zip file by creating a DLL using Ole. I put my own touch on this function, but for some reason, the compiler complains that the function's result is never used...
library unzipper;
{
title : UnZip for InnoSetup
version : 1.0
author : Daniel P. Stasinski
email : daniel#genericinbox.com
begin : Fri Nov 22 17:31:33 MST 2013
license : None
}
uses
Windows,
SysUtils,
ComObj;
const
SHCONTCH_NOPROGRESSBOX = 4;
SHCONTCH_AUTORENAME = 8;
SHCONTCH_RESPONDYESTOALL = 16;
SHCONTF_INCLUDEHIDDEN = 128;
SHCONTF_FOLDERS = 32;
SHCONTF_NONFOLDERS = 64;
UNZIP_SUCCESS = 0;
UNZIP_FAIL = -1;
function UnzipFile(ZipFile, TargetFolder: WideString): Integer; stdcall;
var
shellobj: variant;
ZipFileV, SrcFile: variant;
TargetFolderV, DestFolder: variant;
shellfldritems: variant;
begin
Result:= UNZIP_FAIL;
try
shellobj := CreateOleObject('Shell.Application');
ZipFileV := string(ZipFile);
TargetFolderV := string(TargetFolder);
SrcFile := shellobj.NameSpace(ZipFileV);
DestFolder := shellobj.NameSpace(TargetFolderV);
shellfldritems := SrcFile.Items;
DestFolder.CopyHere(shellfldritems, SHCONTCH_NOPROGRESSBOX or SHCONTCH_RESPONDYESTOALL);
Result:= UNZIP_SUCCESS;
except
on e: exception do begin
Result:= GetLastError;
end;
end;
end;
exports
UnzipFile;
begin
end.
It gives me the message...
[DCC Hint] Unzipper.dpr(35): H2077 Value assigned to 'UnzipFile' never used
This is coming from the first line of code in the function, which I'm initializing to a constant of -1 - which is my own error code if the entire function fails. I don't believe the compiler should be complaining about this, but I could be wrong. I always exterminate all compiler hints and warnings, but in this case, the compiler is more of a complainer.
Is this a fluke in the compiler, or is something wrong in the code?
The compiler is correct, and there's something wrong in the code. :-)
The function will either return UNZIP_SUCCESS if it works, or the result of GetLastError if an exception is raised. Therefore, the first assignment to Result is unnecessary - there is no path of execution that would cause UNZIP_FAIL to be returned.
If you remove the first line result assignment, there is no execution path that leaves result unassigned. Therefore, UNZIP_FAIL value will never be returned.
Related
I am taking over a project with code from another person. I have a PLC that currently has inputs in from pressure sensors and thermocouples. It then scales that data to PSI and temperature in fahrenheit. The way the data is set up from each of those sensors is to be formatted into an array. So, once the data is scaled it is in an array that is also in the Network Variable List of the program. I am trying to take each of these values from the array, record the value every certain amount of time (say 1 recording per second for sake of clarity), and then export each piece of data to a CSV file for every second. Not sure where to even go with this. This is the code I was left with, but I feel as if it it unnecessarily complicated?
//This is the support class for File_Handler
FUNCTION_BLOCK fileWrite
VAR_INPUT
xWrite : BOOL;
sData : STRING(200);
uiLineLength : INT := 200;
sDirectory : STRING := 'C:\ProgramData\CODESYS\CODESYSHMIWinV3\D5050FE1\PlcLogic\data';
//sDirectory : STRING := '/home/cds-apps/PlcLogic/data/';
sFilename : STRING;
END_VAR
VAR_OUTPUT
BytesWritten : __XWORD;
BytesWrittenTotal: DWORD;
xDone: BOOL;
END_VAR
VAR
hFile_: sysfile.RTS_IEC_HANDLE := sysfile.RTS_INVALID_HANDLE;
FileWriteResult: sysfile.RTS_IEC_RESULT;
FileOpenResult: sysfile.RTS_IEC_RESULT;
state: INT;
sys_Us_start: SYSTIME;
sys_Us_end: SYSTIME;
WriteTimeMS: ULINT;
END_VAR
sFilename := CONCAT(sDirectory, sFilename);
hFile_ := SysFileOpen(szFile:= sFilename, am:= ACCESS_MODE.AM_APPEND_PLUS, pResult:= ADR(FileOpenResult));
SysTimeGetUs(pUsTime:=sys_Us_start );
BytesWritten := SysFileWrite(hFile:= hfile_, pbyBuffer:= ADR(sData), ulSize:= uiLineLength, pResult:= ADR(FileWriteResult));
BytesWrittenTotal := BytesWrittenTotal + BytesWritten;
SysTimeGetUs(pUsTime:=sys_Us_end );
WriteTimeMS := (sys_Us_end - sys_Us_start)/1000;
SysFileClose(hFile:= hFile_);
I am not sure where to go with this code. It does create a CSV file, but I was looking to be able to create a CSV file for a piece of data every second? If anyone has any thoughts or resources I could check out that would be great.
A basic example of how to call this routine every second could be the following:
1)
You create a FuncBlock that takes care of calling your logger block.
Let's say you call it LoggerTask.
FUNCTION_BLOCK LoggerTask
VAR_INPUT
sData : STRING(200);
sFilename : STRING;
xExecute : BOOL;
END_VAR
VAR
fbRepeatTask : TON;
fbFileWrite : FileWrite;
uiStep : UINT;
END_VAR
2)
After that create a simple step chain:
(You can obviously extend and customize it as you like, you should add error handling in the case when FileWrite fails to write to file or writes less than expected for example.)
Implementation part:
fbRepeatTask(PT:=T#1S);
fbFileWrite(sData := sData, sFileName := sFileName);
IF xExecute
AND uiStep = 0
THEN
uiStep := 10;
ELSIF NOT xExecute
THEN
uiStep := 0;
fbFileWrite.xWrite := FALSE;
fbRepeatTask.IN := FALSE;
END_IF
CASE uiStep OF
10:
fbFileWrite.xWrite := TRUE;
IF fbFileWrite.xDone
THEN
fbFileWrite.xWrite := FALSE;
uiStep := 20;
END_IF
20:
fbRepeatTask.IN := TRUE;
IF fbRepeatTask.Q
THEN
fbRepeatTask.IN := FALSE;
uiStep := 10;
END_IF
END_CASE
3)
As you can see this block gets executed as soon as xExecute is set to true.
In order to reset the step chain set xExecute to false.
Just run this block cyclically for example like this fbLoggerTask(xExecute := TRUE);
I don't think you posted all the code of your FileWrite block because xDone is not set and xWrite is not checked anywhere.
So make sure that xDone is set to true for one cycle after the String is written to the file (if it's not already been implemented).
I am trying to use the DSiGetHtmlFormatFromClipboard function from the well known DSiWin32 library.
Edit: There is a much newer version of DSIWin32.pas 1.94 from 2016-10-19 which is contained in the current version of OmniThreadLibrary_3.07.1. The one I've linked to in the first line of my question is much older: 1.66 from 2012-04-20. However, also in this newer version of DSIWin32.pas the function DSiGetHtmlFormatFromClipboard does not work although I've made sure that no other clipboard programs are running.
So I put some text on the clipboard which includes the HTML format e.g. by copying some text from Chrome web-browser.
And then I use this code to get the HTML format from the clipboard:
if DSiWin32.DSiIsHtmlFormatOnClipboard then
begin
CodeSite.Send('HTML-Format string:', DSiWin32.DSiGetHtmlFormatFromClipboard);
end;
While the DSiIsHtmlFormatOnClipboard function does work (it gives back True if there is HTML Format on the clipboard and gives back False if there is no HTML Format on the clipboard), the DSiGetHtmlFormatFromClipboard function always gives back an empty string although there is HTML Format in the clipboard:
So I debugged function DSiGetHtmlFormatFromClipboard: string; in DSiWin32.pas:
On this line:
hClipData := GetClipboardData(GCF_HTML);
hClipData is always 0, so the following code is not executed.
GetClipboardData is a function from Winapi.Windows and according to MSDN documentation:
Retrieves data from the clipboard in a specified format. The clipboard
must have been opened previously.
Which is the case in the DSiWin32 code.
So why does the DSiGetHtmlFormatFromClipboard always give back an empty string?
OS: Windows 7 x64
GetLastError retrieved immediately after the line hClipData := GetClipboardData(GCF_HTML);:
ERROR_CLIPBOARD_NOT_OPEN 1418 (0x58A) Thread does not have a
clipboard open.
This is strange because the preceding line is: Win32Check(OpenClipboard(0)); and it does not fail.
Here is the relevant parts of the MCVE:
var
GCF_HTML: UINT;
function DSiIsHtmlFormatOnClipboard: boolean;
begin
Result := IsClipboardFormatAvailable(GCF_HTML);
end; { DSiIsHtmlFormatOnClipboard }
function DSiGetHtmlFormatFromClipboard: string;
var
hClipData : THandle;
idxEndFragment : integer;
idxStartFragment: integer;
pClipData : PChar;
begin
Result := '';
if DSiIsHtmlFormatOnClipboard then
begin
Win32Check(OpenClipboard(0));
try
hClipData := GetClipboardData(GCF_HTML);
if hClipData = 0 then
RaiseLastOSError;
pClipData := GlobalLock(hClipData);
Win32Check(assigned(pClipData));
try
idxStartFragment := Pos('<!--StartFragment-->', pClipData); // len = 20
idxEndFragment := Pos('<!--EndFragment-->', pClipData);
if (idxStartFragment >= 0) and (idxEndFragment >= idxStartFragment) then
Result := Copy(pClipData, idxStartFragment + 20, idxEndFragment - idxStartFragment - 20);
finally GlobalUnlock(hClipData); end;
finally Win32Check(CloseClipboard); end;
end;
end; { DSiGetHtmlFormatFromClipboard }
procedure TForm1.Button1Click(Sender: TObject);
begin
if DSiIsHtmlFormatOnClipboard then
ShowMessage(DSiGetHtmlFormatFromClipboard)
else
ShowMessage('No HTML Format on Clipboard');
end;
initialization
GCF_HTML := RegisterClipboardFormat('HTML Format');
end.
I have problem inserting sql results into TStringGrid.I have following code:
var i:Integer;
begin
SqlQuery1.SQL.Text:= 'SELECT * FROM `users`';
SqlQuery1.Open;
MySql55Connection1.Open;
i:= 0;
while not SQLQUERY1.EOF do
begin
i:= i+1;
StringGrid1.Cells[0,i]:= SqlQuery1.FieldByName('Username').AsString;
StringGrid1.Cells[1,i]:= SqlQuery1.FieldByName('Password').AsString;
StringGrid1.Cells[2,i]:= SqlQuery1.FieldByName('id').AsString;
end;
end;
So in my database only one line. But program adding a lot of copies of this line in StringGrid and it causes error(Index out of bounds).
Danger
It appears you are storing passwords in plain text form in a database.
This is an extremely bad idea.
Never store passwords in a database.
Use salted hashes instead.
See: How do I hash a string with Delphi?
There are a couple of other problems in your code:
You don't ensure that the stringgrid has enough rows to hold your data.
You're not moving to the next line in the query.
You're opening the query before the connection is open.
You're using FieldByName inside a loop, this is going to be very slow.
Simple solution
Use a DBGrid.
If you insist on using a StringGrid
I suggest refactoring the code like so:
var
i,a:Integer;
FUsername, FPasswordHash, Fid, FSalt: TField;
begin
if not(MySQl55Connection.Active) then MySql55Connection1.Open;
SqlQuery1.SQL.Text:= 'SELECT * FROM users'; //only use backticks on reserved words.
SqlQuery1.Open;
FUsername:= SqlQuery1.FieldByName('Username');
//do not use plain text passwords!!
FPasswordHash:= SQLQuery1.FieldByName('SaltedPasswordHashUsingSHA256');
FId:= SqlQuery1.FieldByName('id');
FSalt:= SQLQuery1.FieldByName('SaltUsingCryptoRandomFunction');
a:= StringGrid1.FixedRowCount;
if SQLQuery1.RecordCount = -1 then StringGrid1.RowCount = 100 //set it to something reasonable.
else StringGrid1.RowCount:= a + SQLQuery1.RecordCount;
//SQLQuery1.DisableControls
try
i:= StringGrid1.FixedRowCount;
while not(SQLQuery1.EOF) do begin
if i >= StringGrid1.RowCount then StringGrid1.RowCount:= i;
StringGrid1.Cells[0,i]:= FUserName.AsString;
StringGrid1.Cells[1,i]:= FPasswordHash.AsString;
StringGrid1,Cells[3,i]:= FSaltInHex.AsString;
StringGrid1.Cells[2,i]:= FId.AsString;
SQLQuery1.Next; //get next row.
Inc(i);
end; {while}
finally
//just in case you want to do endupdate or close the SQLQuery or do SQLQuery1.EnableControls
end;
end;
Basic security example
Here's how to hash a password:
Download Lockbox3.
Put a THash on your form and set the hash property to SHA-512.
Use the following code to produce a hash result.
function StringToHex(const input: string): AnsiString;
var
NumBytes, i: Integer;
B: Byte;
W: word;
Wa: array[0..1] of byte absolute W;
begin
NumBytes := input.length * SizeOf(Char);
SetLength(Result, NumBytes * 2);
for i := 1 to NumBytes do begin
if SizeOf(Char) = 1 then begin
B:= Byte(input[i]);
BinToHex(#B, #Result[(I*2)+1], 1);
end else begin
W:= Word(input[i]);
BinToHex(#Wa[0], #Result[(i*4+0)],1);
BinToHex(#Wa[1], #Result[(i*4+1)],1);
end; {else}
end;
end;
function TForm1.HashPassword(var Password: string; const Salt: string): string;
var
KillPassword: pbyte;
begin
Hash1.HashString(StringToHex(Password)+StringToHex(Salt));
KillPassword:= PByte(#Password[1]);
FillChar(KillPassword^, Length(Password)*SizeOf(Char), #0); //remove password from memory.
Password:= ''; //Now free password.
end;
function GenerateSalt( ByteCount: integer = 32): string;
var
Buffer: TMemoryStream;
begin
Buffer := TMemoryStream.Create;
try
Buffer.Size := ByteCount;
RandomFillStream( Buffer);
result := Stream_to_Base64( Buffer);
finally
Buffer.Free
end;
end;
This is the minimum amount of work you can get away with whilst still having things secure.
Do not think that your passwords are unimportant because you just have a toy database, because people reuse passwords and thus your toy passwords end up being the same passwords used for online banking and such.
People are lazy....
I need to go through a HTML string and replace characters with 0 (zero), except tags, spaces and line breaks. I created this code bellow, but it is too slow. Please, can someone help me to make it faster (optimize)?
procedure TForm1.btn1Click(Sender: TObject);
var
Txt: String;
Idx: Integer;
Tag: Boolean;
begin
Tag := False;
Txt := mem1.Text;
For Idx := 0 to Length(Txt) - 1 Do
Begin
If (Txt[Idx] = '<') Then
Tag := True Else
If (Txt[Idx] = '>') Then
Begin
Tag := False;
Continue;
end;
If Tag Then Continue;
If (not (Txt[Idx] in [#10, #13, #32])) Then
Txt[Idx] := '0';
end;
mem2.Text := Txt;
end;
The HTML text will never have "<" or ">" outside tags (in the middle of text), so I do not need to worry about this.
Thank you!
That looks pretty straightforward. It's hard to be sure without profiling the code against the data you're using, (which is always a good idea; if you need to optimize Delphi code, try running it through Sampling Profiler first to get an idea where you're actually spending all your time,) but if I had to make an educated guess, I'd guess that your bottleneck is in this line:
Txt[Idx] := '0';
As part of the compiler's guarantee of safe copy-on-write semantics for the string type, every write to an individual element (character) of a string involves a hidden call to the UniqueString routine. This makes sure that you're not changing a string that something else, somewhere else, holds a reference to.
In this particular case, that's not necessary, because you got the string fresh in the start of this routine and you know it's unique. There's a way around it, if you're careful.
CLEAR AND UNAMBIGUOUS WARNING: Do not do what I'm about to explain without making sure you have a unique string first! The easiest way to accomplish this is to call UniqueString manually. Also, do not do anything during the loop that could assign this string to any other variable. While we're doing this, it's not being treated as a normal string. Failure to heed this warning can cause data corruption.
OK, now that that's been explained, you can use a pointer to access the characters of the string directly, and get around the compiler's safeguards, like so:
procedure TForm1.btn1Click(Sender: TObject);
var
Txt: String;
Idx: Integer;
Tag: Boolean;
current: PChar; //pointer to a character
begin
Tag := False;
Txt := mem1.Text;
UniqueString(txt); //very important
if length(txt) = 0 then
Exit; //If you don't check this, the next line will raise an AV on a blank string
current := #txt[1];
dec(current); //you need to start before element 1, but the compiler won't let you
//assign to element 0
For Idx := 0 to Length(Txt) - 1 Do
Begin
inc(current); //put this at the top of the loop, to handle Continue cases correctly
If (current^ = '<') Then
Tag := True Else
If (current^ = '>') Then
Begin
Tag := False;
Continue;
end;
If Tag Then Continue;
If (not (current^ in [#10, #13, #32])) Then
current^ := '0';
end;
mem2.Text := Txt;
end;
This changes the metaphor. Instead of indexing into the string as an array, we're treating it like a tape, with the pointer as the head, moving forward one character at a time, scanning from beginning to end, and changing the character under it when appropriate. No redundant calls to UniqueString, and no repeatedly calculating offsets, which means this can be a lot faster.
Be very careful when using pointers like this. The compiler's safety checks are there for a good reason, and using pointers steps outside of them. But sometimes, they can really help speed things up in your code. And again, profile before trying anything like this. Make sure that you know what's slowing things down, instead of just thinking you know. If it turns out to be something else that's running slow, don't do this; find a solution to the real problem instead.
Edit: Looks like I was wrong - UniqueString is not the problem. The actual bottleneck seems to be accessing the string by character. Given that my entire answer was irrelevent, I've completely replaced it.
If you use a PChar to avoid recalculating the string offset, while still updating the string via Txt[Idx], the method is much faster (5 seconds down to 0.5 seconds in my test of 1000 runs).
Here's my version:
procedure TForm1.btn1Click(Sender: TObject);
var
Idx: Integer;
Tag: Boolean;
p : PChar;
Txt : string;
begin
Tag := False;
Txt := Mem1.Text;
p := PChar(txt);
Dec(p);
For Idx := 0 to Length(Txt) - 1 Do
Begin
Inc(p);
If (not Tag and (p^ = '<')) Then begin
Tag := True;
Continue;
end
Else If (Tag and (p^ = '>')) Then
Begin
Tag := False;
Continue;
end;
If Tag Then Continue;
If (not (p^ in [#10, #13, #32])) Then begin
Txt[Idx] := '0';
end;
end;
mem2.Text := Txt;
end;
I did some profiling and came up with this solution.
A test for > #32 instead of [#10,#13,#32] gains some speed (thanks #DavidHeffernan).
A better logic in the loop also gives a bit extra speed.
Accessing the string exclusively with the help of a PChar is more effective.
procedure TransformHTML( var Txt : String);
var
IterCnt : Integer;
PTxt : PChar;
tag : Boolean;
begin
PTxt := PChar(Txt);
Dec(PTxt);
tag := false;
for IterCnt := 0 to Length(Txt)-1 do
begin
Inc(PTxt);
if (PTxt^ = '<') then
tag := true
else
if (PTxt^ = '>') then
tag := false
else
if (not tag) and (PTxt^ > #32) then
PTxt^ := '0';
end;
end;
This solution is about 30% more effective than Mason's solution and 2.5 times more effective than Blorgbeard's.
I need my program to catch TimeOutException every time SerialPort Read Times out, but it fails to do that. In fact, the program breaks when it goes to read and throws this exceptions, "The I/O operation has been aborted because of either a thread exit or an application request."
Here is how SerialPort Instantiated:
dxComm = class(System.Windows.Forms.Form)
private
protected
public
constructor;
serialPort1:System.IO.Ports.SerialPort;
thr:Thread;
method mythread;
end;
constructor DXComm;
begin
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
SerialPort1 := new System.Io.Ports.SerialPort();
thr:=nil;
end;
Here is how thread is created:
thr:= new Thread(#mythread);
thr.Start;
Here is the SerialPort settings:
case TypeDXCard.SelectedIndex of
0:
begin
DXProtocol := TDXProtocol.tDxTwo;
msglen := 6;
rmsglen := 5;
end;
1:
begin
DXProtocol := TDXProtocol.tDxExpress;
msglen:=0;
rmsglen:=0;
end;
else
begin
DXProtocol := TDXProtocol.tDxTwo;
msglen := 6;
rmsglen := 5;
end;
end;
dx := ord(DXProtocol);
if (SerialPort1 <> nil) then
begin
case CommPort.SelectedIndex of
0: SerialPort1.PortName := 'COM1';
1: SerialPort1.PortName := 'COM2';
2: SerialPort1.portName := 'COM3';
3: SerialPort1.PortName := 'COM4';
end;
case BaudRate.SelectedIndex of
0: SerialPort1.BaudRate := 1200;
1: SerialPort1.BaudRate := 2400;
2: SerialPort1.BaudRate := 4800;
3: SerialPort1.BaudRate := 9600;
4: SerialPort1.BaudRate := 19200;
5: SerialPort1.BaudRate := 38400;
6: SerialPort1.BaudRate := 57600;
7: SerialPort1.BaudRate := 115200;
end;
if (EvenParity.Checked) then
SerialPort1.Parity := System.IO.Ports.Parity.Even
else
SerialPort1.Parity := System.IO.Ports.Parity.None;
end;
with SerialPort1 do
begin
SerialPort1.DataBits:=8;
SerialPort1.DtrEnable:=true;
SerialPort1.ReadBufferSize:= 4096;
SerialPort1.ReadTimeout:=TimeOutDelay*2;
SerialPort1.RtsEnable:=true;
SerialPort1.StopBits:=System.IO.Ports.StopBits.One;
SerialPort1.WriteTimeout:=1000;
SerialPort1.Handshake := HandShake.None;
SerialPort1.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(#MySerialData);
end;
Here is my Thread that handles the SerialPort.Write:
method DXcomm.mythread;
var x,y:Integer;
begin
while true do
begin
Thread.Sleep(ScanTime);
SerialPort1.RtsEnable:=true;
SerialPort1.DiscardOutBuffer;
SendMessage; <---------Assembles the bytes and sends it out
while SerialPort1.BytesToWrite>0 do;
thread.Sleep(4);
SerialPort1.DiscardInBuffer;
SerialPort1.RtsEnable:=false;
if (stopthread) then
break;
end;
end;
Here is the event for reading bytes from the serialport:
method DXComm.MySerialData(sender: System.Object; e:SerialDataReceivedEventArgs);
begin
if not SerialPort1.IsOpen then Exit;
try
SerialPort1.Read(RXMsg,0,5); <------Here is Where my program throws that exception when I check on TimeOutException down below.
if changeFlag then
begin
changeList.IncRxCnt;
FixUpChangeList;
end
else
ActiveUnit.Retreive;
except on ex: TimeOutException do <----This line of code fails.
//except on ex: Exception do <----This line of code works fine, but executes all the time instead of just only when there is an exception.
begin
//TimeOut Exception
ActiveUnit.Timeout;
SerialPort1.DiscardInBuffer;
SerialPort1.DiscardOutBuffer;
end;
end;
end;
What am I doing wrong? I need to catch SerialPort.Read TimeOuts and take appropriate action.
It seems you're using the Serial port as a component on a form but doing the reading / writing in a background thread?
Or, as I got it, you write in a background thread and then read on some other, random, thread (the one that is calling the Event you react on).
That is a problem, because the background thread then (internally) want's to update the Serial Port 'Control', which isn't allowed from Background threads. The problem could also be that the thread waiting to read is interrupted by the other thread that is writing in the infinite loop and thus causes the I/O exception. It's a bit of guessing involved here.
First shot:
You have to either create the Serial Port dynamically (i.e. not putting it on your form but instanciating and configuring it by code) to prevent that or (strongly discouraged though), set System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls to false.
Second shot:
On the other hand I would strongly suggest to make definetly sure that only one thread at all is working with the serial port. Not writing in one thread and reading from another. Do everything that is related to this serial I/O in one single thread. Read OR write, but do not try to do both at the same time from different threads.
Instead of:
SerialPort1.Read(RXMsg,0,5);
Does Delphi have a serial function that returns the number of characters received and waiting to be read?
For example(in probably poor pseudo code):
while (Not Timeout)
{
if (serialport1.characterswaiting)
{
SerialPort1.Read(RXMsg,0,5);
}
}
I believe the problem lies in the fact that I am writing to the serialport in my own thread or user-defined thread and reading from the serialport in another. The event datareceived is part of the main thread of the program, I think.
As pointed out by Sebastian, it makes sense that writing and reading from the same thread should solve my serial communication problem. Indeed, it seems have to solved my serial communication, although it is little less than 100%. That's a timing issue, since my program depends on fixed time delays.
The steps: Within my thread, I write to the serial port and wait for sometime to read the response from the serialport. This seems to have greatly improved the communication, but now I don't wait for the datareceived event to fire once it sees something in the input buffer.
Correct me if I am wrong in my thinking or reasoning.