我需要拦截
Windows关闭,并执行一些DB查询,之后我的应用程序将关闭.
我在Windows 10上使用Delphi XE10在FMX项目
我在Windows 10上使用Delphi XE10在FMX项目
我试过的是下面的代码,但它不起作用
private
{ Private declarations }
{$IFDEF MSWINDOWS}
procedure WMQueryEndSession(var Msg: TWMQueryEndSession); message WM_QUERYENDSESSION;
procedure WMEndSession(var Msg : TWMQueryEndSession); message WM_ENDSESSION ;
{$ENDIF}
end;
procedure TfMain.WMQueryEndSession(var Msg: TWMQueryEndSession);
var
lista:TStringList;
begin
{$IFDEF MSWINDOWS}
try
lista:=TStringList.Create;
lista.Add(FOrmatDateTime('DD/MM/YYYY HH:NN:SS',now)+' event WMQueryEndSession');
Lista.SaveToFile(froot+formatdatetime('YYMMDDHHNNSSZZZ',now)+'.log');
SincroClose();
lista.Add(FOrmatDateTime('DD/MM/YYYY HH:NN:SS',now)+' Done');
Lista.SaveToFile(froot+formatdatetime('YYMMDDHHNNSSZZZ',now)+'.log');
finally
lista.Free;
end;
{$ENDIF}
inherited;
end;
procedure TfMain.WMEndSession(var Msg: TWMQueryEndSession);
var
lista:TStringList;
begin
{$IFDEF MSWINDOWS}
try
lista:=TStringList.Create;
lista.Add(FOrmatDateTime('DD/MM/YYYY HH:NN:SS',now)+' WMEndSession');
Lista.SaveToFile(froot+formatdatetime('YYMMDDHHNNSSZZZ',now)+'.log');
finally
lista.Free;
end;
{$ENDIF}
inherited;
end;
procedure TfMain.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
var lista:TStringList;
begin
{$IFDEF MSWINDOWS}
CanClose:=false;
try
lista:=TStringList.Create;
lista.Add(FOrmatDateTime('DD/MM/YYYY HH:NN:SS',now)+' FormCloseQuery');
Lista.SaveToFile(froot+formatdatetime('YYMMDDHHNNSSZZZ',now)+'.log');
CanClose:=true;
finally
lista.Free;
end;
{$ENDIF}
end;
只有正常的关闭应用程序,才能正常工作,在FormCloseQuery事件下,但是当Windows关闭时,我的应用程序将关闭而不保存任何数据
解决方法
FormCloseQuery的工作原理是由框架公开的.由于您的邮件处理程序永远不会被调用,所以您的应用程序不会在Windows关闭时保存任何数据.消息处理仅适用于VCL应用程序,fmx应用程序具有与
documented不同的消息传递机制.
简要说明here意味着可以在fmx框架中接收来自OS的通知.但是,我不知道这是否包括关机通知,并且可以设置返回值,因为文档提到的消息对象只能被读取.
直到你知道fmx消息传递机制是如何工作的,如果它满足要求,你可以通过传统方式对你的窗体进行子类化.下面的示例使用SetWindowSubclass.
...
protected
{$IFDEF MSWINDOWS}
procedure CreateHandle; override;
procedure DestroyHandle; override;
procedure WMQueryEndSession(var Msg: TWMQueryEndSession); message WM_QUERYENDSESSION;
procedure WMEndSession(var Msg: TWMEndSession); message WM_ENDSESSION;
{$ENDIF}
...
implementation
{$IFDEF MSWINDOWS}
uses
FMX.Platform.Win,Winapi.Commctrl;
function SubclassProc(Wnd: HWND; Msg: UINT; wParam: WPARAM; lParam: LPARAM;
uIdSubclass: UINT_PTR; RefData: DWORD_PTR): LRESULT; stdcall;
var
Self: TfMain;
Message: TMessage;
begin
Result := DefSubclassProc(Wnd,Msg,wParam,lParam);
case Msg of
WM_QUERYENDSESSION,WM_ENDSESSION:
begin
Self := TfMain(RefData);
Message.Msg := Msg;
Message.WParam := wParam;
Message.LParam := lParam;
Message.Result := Result;
Self.Dispatch(Message);
Result := Message.Result;
end;
end;
end;
procedure TfMain.CreateHandle;
var
Wnd: HWND;
begin
inherited;
Wnd := WindowHandleToPlatform(Self.Handle).Wnd;
SetWindowSubclass(Wnd,SubclassProc,1,DWORD_PTR(Self));
end;
procedure TfMain.DestroyHandle;
var
Wnd: HWND;
begin
Wnd := WindowHandleToPlatform(Self.Handle).Wnd;
RemoveWindowSubclass(Wnd,1);
inherited;
end;
procedure TfMain.WMQueryEndSession(var Msg: TWMQueryEndSession);
begin
// do not call inherited here,there's no inherited handling
end;
procedure TfMain.WMEndSession(var Msg: TWMEndSession);
begin
// do not call inherited here,there's no inherited handling
end;
var
ICC: TInitCommonControlsEx;
initialization
ICC.dwSize := SizeOf(ICC);
ICC.dwICC := ICC_STANDARD_CLASSES;
InitCommonControlsEx(ICC);
{$ENDIF}