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PORaising Exception in TThread Execute?
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  1. PORaising Exception in TThread Execute?
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    copied!<p>I just realized that my exceptions are not being shown to the user in my threads!</p> <p>At first I used this in my thread for raising the exception, which does not work:</p> <pre><code>except on E:Exception do begin raise Exception.Create('Error: ' + E.Message); end; </code></pre> <p>The IDE shows me the exceptions, but my app does not!</p> <p>I have looked around for a solution, this is what I found:</p> <p><a href="https://stackoverflow.com/questions/3627743/delphi-thread-exception-mechanism">Delphi thread exception mechanism</a></p> <p><a href="http://www.experts-exchange.com/Programming/Languages/Pascal/Delphi/Q_22039681.html" rel="nofollow noreferrer">http://www.experts-exchange.com/Programming/Languages/Pascal/Delphi/Q_22039681.html</a></p> <p>And neither of these worked for me.</p> <p>Here's my Thread unit:</p> <pre><code>unit uCheckForUpdateThread; interface uses Windows, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient, IdHTTP, GlobalFuncs, Classes, HtmlExtractor, SysUtils, Forms; type TUpdaterThread = class(TThread) private FileGrabber : THtmlExtractor; HTTP : TIdHttp; AppMajor, AppMinor, AppRelease : Integer; UpdateText : string; VersionStr : string; ExceptionText : string; FException: Exception; procedure DoHandleException; procedure SyncUpdateLbl; procedure SyncFinalize; public constructor Create; protected procedure HandleException; virtual; procedure Execute; override; end; implementation uses uMain; { TUpdaterThread } constructor TUpdaterThread.Create; begin inherited Create(False); end; procedure TUpdaterThread.Execute; begin inherited; FreeOnTerminate := True; if Terminated then Exit; FileGrabber := THtmlExtractor.Create; HTTP := TIdHTTP.Create(nil); try try FileGrabber.Grab('http://jeffijoe.com/xSky/Updates/CheckForUpdates.php'); except on E: Exception do begin UpdateText := 'Error while updating xSky!'; ExceptionText := 'Error: Cannot find remote file! Please restart xSky and try again! Also, make sure you are connected to the Internet, and that your Firewall is not blocking xSky!'; HandleException; end; end; try AppMajor := StrToInt(FileGrabber.ExtractValue('AppMajor[', ']')); AppMinor := StrToInt(FileGrabber.ExtractValue('AppMinor[', ']')); AppRelease := StrToInt(FileGrabber.ExtractValue('AppRelease[[', ']')); except on E:Exception do begin HandleException; end; end; if (APP_VER_MAJOR &lt; AppMajor) or (APP_VER_MINOR &lt; AppMinor) or (APP_VER_RELEASE &lt; AppRelease) then begin VersionStr := Format('%d.%d.%d', [AppMajor, AppMinor, AppRelease]); UpdateText := 'Downloading Version ' + VersionStr; Synchronize(SyncUpdateLbl); end; finally FileGrabber.Free; HTTP.Free; end; Synchronize(SyncFinalize); end; procedure TUpdaterThread.SyncFinalize; begin DoTransition(frmMain.TransSearcher3, frmMain.gbLogin, True, 500); end; procedure TUpdaterThread.SyncUpdateLbl; begin frmMain.lblCheckingForUpdates.Caption := UpdateText; end; procedure TUpdaterThread.HandleException; begin FException := Exception(ExceptObject); try Synchronize(DoHandleException); finally FException := nil; end; end; procedure TUpdaterThread.DoHandleException; begin Application.ShowException(FException); end; end. </code></pre> <p>If you need more info just let me know.</p> <p>Again: The IDE catches all the exceptions, but my program does not show them.</p> <p>EDIT: It was Cosmin's solution that worked in the end - and the reason it didn't at first, was because I didn't add the ErrMsg variable, instead I just placed whatever the variable would contain into the Synchronize, which would NOT work, however I have NO idea why. I realized it when I had no other ideas, and I just messed around with the solutions.</p> <p>As always, the joke's on me. =P</p>
 

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