Thread Application Implementation in TThread :: STRCPY

2010/04/14 13:28

Thread Application Implementation in TThread

2010/04/14 13:28 in Delphi

Delphi provides class for thread application as TThread.

Following is the simple example for thread application.

type
TForm1 = class(TForm)
Memo1: TMemo;
GroupBox1: TGroupBox;
seTimeToWork: TSpinEdit;
Label1: TLabel;
btnCreate: TButton;
btnTerminate: TButton;
procedure FormShow(Sender: TObject);
procedure btnCreateClick(Sender: TObject);
procedure btnTerminateClick(Sender: TObject);

private
FThread:TThread;
procedure EnableButtons;
procedure OnTerminate(Sender:TObject);
end;

TMyThread=class(TThread)
private
FTimeToWork:integer;
protected
procedure Execute;override;
public
constructor Create(TimeToWork:integer);
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

// TMyThread

constructor TMyThread.Create(TimeToWork: integer);
begin
FTimeToWork:=TimeToWork;
inherited Create(True);
end;

procedure TMyThread.Execute;
var
T:Integer;
begin
t:=FTimeToWork;
Form1.Memo1.Lines.Add('Begin execution');
while not Terminated and (t>0) do
begin
Form1.Memo1.Lines.Add(format('Remaining %5.2f%%',[t/FTimeToWork*100]));
Sleep(500);
dec(t,500);
end;

if Terminated then
Form1.Memo1.Lines.Add('Terminated by user');

Form1.Memo1.Lines.Add('Finish execution');
end;

// TForm1
procedure TForm1.EnableButtons;
begin
btnCreate.Enabled:=not Assigned(FThread);
btnTerminate.Enabled:= Assigned(FThread);
end;

procedure TForm1.FormShow(Sender: TObject);
begin
EnableButtons;
end;

procedure TForm1.btnCreateClick(Sender: TObject);
begin
FThread:=TMyThread.Create(seTimeToWork.Value);
FThread.OnTerminate:=OnTerminate;
EnableButtons;
FThread.Resume;
end;

procedure TForm1.btnTerminateClick(Sender: TObject);
begin
FThread.Terminate;
end;

procedure TForm1.OnTerminate(Sender: TObject);
begin
FThread:=nil;
EnableButtons;
end;

end.

Another posts included in "Delphi"

Is there directory selection VCL component in Delphi ? (0)	2009/09/09
How to launch application ? (0)	2009/09/09
How to print external document ? (0)	2009/09/09
Delphi API to get windows temporary directory (0)	2009/09/03
Delphi API to get the current working directory (0)	2009/09/03