如何处理Ctrl+;Delphi控制台应用程序中的C?
是否有最佳实践和代码片段可以展示如何在Delphi控制台应用程序中处理Ctrl+C 我找到了一些文章,其中提供了有关调试器可能出现的问题的一些信息,包括异常处理、DLL卸载、stdin关闭和最终确定。来自Windows API(): HandlerRoutine函数是控制台进程指定用于处理进程接收的控制信号的函数。函数可以有任何名称如何处理Ctrl+;Delphi控制台应用程序中的C?,delphi,console,Delphi,Console,是否有最佳实践和代码片段可以展示如何在Delphi控制台应用程序中处理Ctrl+C 我找到了一些文章,其中提供了有关调试器可能出现的问题的一些信息,包括异常处理、DLL卸载、stdin关闭和最终确定。来自Windows API(): HandlerRoutine函数是控制台进程指定用于处理进程接收的控制信号的函数。函数可以有任何名称 BOOL WINAPI HandlerRoutine( DWORD dwCtrlType // control signal type );
BOOL WINAPI HandlerRoutine(
DWORD dwCtrlType // control signal type
);
在Delphi中,处理程序例程应该如下所示:
function console_handler( dwCtrlType: DWORD ): BOOL; stdcall;
begin
// Avoid terminating with Ctrl+C
if ( CTRL_C_EVENT = dwCtrlType ) then
result := TRUE
else
result := FALSE;
end;
我编写了一个小程序,向您展示如何正确停止后台任务。 希望它更清楚 ThreadConsoleApplication.dpr文件的内容:
program ThreadConsoleApplication;
{$APPTYPE CONSOLE}
uses
SysUtils,
Windows,
Classes;
type
{ **
* Classe TQueueReaderTestApplication
* }
TThreadConsoleApplication = class(TThread)
public
procedure Execute; override;
constructor Create; virtual;
destructor Destroy; override;
class function getInstance: TThreadConsoleApplication;
end;
function TThreadConsoleApplication_consoleCtrlHandler(dwCtrlType: DWORD): BOOL;
stdcall; forward;
{ **
* Classe TQueueReaderTestApplication
* }
constructor TThreadConsoleApplication.Create;
begin
inherited Create(True { CreateSuspended } );
Windows.setConsoleCtrlHandler(@TThreadConsoleApplication_consoleCtrlHandler,
True { add } );
end;
var
threadConsoleApplicationInstance: TThreadConsoleApplication = nil;
destructor TThreadConsoleApplication.Destroy;
begin
threadConsoleApplicationInstance := nil;
inherited;
end;
procedure TThreadConsoleApplication.Execute;
begin
System.Writeln('[TThreadConsoleApplication.Execute] begin');
try
while not Terminated do
begin
System.Writeln('[TThreadConsoleApplication.Execute] running ...');
Windows.Sleep(1000 { dwMilliseconds } );
end;
finally
System.Writeln('[TThreadConsoleApplication.Execute] end');
end;
end;
class function TThreadConsoleApplication.getInstance: TThreadConsoleApplication;
begin
if nil = threadConsoleApplicationInstance then
begin
threadConsoleApplicationInstance := TThreadConsoleApplication.Create;
end;
Result := threadConsoleApplicationInstance;
end;
function TThreadConsoleApplication_consoleCtrlHandler(dwCtrlType: DWORD): BOOL;
begin
Result := False;
if Windows.CTRL_C_EVENT = dwCtrlType then
begin
TThreadConsoleApplication.getInstance.Terminate;
Result := True;
end;
end;
var
thread: TThread;
begin
System.Writeln('[program] begin');
try
thread := nil;
try
thread := TThreadConsoleApplication.getInstance;
thread.Resume;
System.Writeln('[program] press a CTRL+C to stop running');
thread.WaitFor;
finally
thread.Free;
end;
System.Writeln('[program] end');
except
on E: Exception do
begin
System.Writeln(System.ErrOutput, '[program] end with error');
System.Writeln(System.ErrOutput, E.ClassName, ': ', E.Message);
end;
end;
System.Writeln('[program] press a key to quit');
System.Readln;
end.
好的,这显示了如何禁用Ctrl+C-我应该澄清我的问题:在检测到Ctrl+C后,如何执行干净的应用程序关闭?哦,我明白了。如我的例子所示,如果您捕获Ctrl+C,您可以设置一种“标志”,并在需要时正常终止。我刚刚想起了“break:=false;”,我曾将其放入我的Turbo Pascal程序中以禁用Ctrl-break。啊,怀旧……要记住一件非常重要的事情,那就是HandlerRoutine在一个单独的线程中运行。如果您自己不启动任何其他线程,请将IsMultithread全局变量设置为True,以便您执行的任何内存操作都是安全的。调用约定也很重要。回调函数必须使用stdcall调用约定,否则程序将神秘崩溃。
program ThreadConsoleApplication;
{$APPTYPE CONSOLE}
uses
SysUtils,
Windows,
Classes;
type
{ **
* Classe TQueueReaderTestApplication
* }
TThreadConsoleApplication = class(TThread)
public
procedure Execute; override;
constructor Create; virtual;
destructor Destroy; override;
class function getInstance: TThreadConsoleApplication;
end;
function TThreadConsoleApplication_consoleCtrlHandler(dwCtrlType: DWORD): BOOL;
stdcall; forward;
{ **
* Classe TQueueReaderTestApplication
* }
constructor TThreadConsoleApplication.Create;
begin
inherited Create(True { CreateSuspended } );
Windows.setConsoleCtrlHandler(@TThreadConsoleApplication_consoleCtrlHandler,
True { add } );
end;
var
threadConsoleApplicationInstance: TThreadConsoleApplication = nil;
destructor TThreadConsoleApplication.Destroy;
begin
threadConsoleApplicationInstance := nil;
inherited;
end;
procedure TThreadConsoleApplication.Execute;
begin
System.Writeln('[TThreadConsoleApplication.Execute] begin');
try
while not Terminated do
begin
System.Writeln('[TThreadConsoleApplication.Execute] running ...');
Windows.Sleep(1000 { dwMilliseconds } );
end;
finally
System.Writeln('[TThreadConsoleApplication.Execute] end');
end;
end;
class function TThreadConsoleApplication.getInstance: TThreadConsoleApplication;
begin
if nil = threadConsoleApplicationInstance then
begin
threadConsoleApplicationInstance := TThreadConsoleApplication.Create;
end;
Result := threadConsoleApplicationInstance;
end;
function TThreadConsoleApplication_consoleCtrlHandler(dwCtrlType: DWORD): BOOL;
begin
Result := False;
if Windows.CTRL_C_EVENT = dwCtrlType then
begin
TThreadConsoleApplication.getInstance.Terminate;
Result := True;
end;
end;
var
thread: TThread;
begin
System.Writeln('[program] begin');
try
thread := nil;
try
thread := TThreadConsoleApplication.getInstance;
thread.Resume;
System.Writeln('[program] press a CTRL+C to stop running');
thread.WaitFor;
finally
thread.Free;
end;
System.Writeln('[program] end');
except
on E: Exception do
begin
System.Writeln(System.ErrOutput, '[program] end with error');
System.Writeln(System.ErrOutput, E.ClassName, ': ', E.Message);
end;
end;
System.Writeln('[program] press a key to quit');
System.Readln;
end.