如何限制程序只能运行一个

Question

程序如果运行好几次开几个的话,操作数据库就会有问题,如果限制这个进程在同一时间只能有1个??有没有相关的api函数,或者是其他什么好方法

Answer 1

用CreateMutex函数，你搜索一下，会有很多例子的

Answer 2

program IhomeOA;uses
  Forms,
  Windows,
  Controls,
  U_main in 'U_main.pas' {Frmmain},
  U_login in 'U_login.pas' {Frmlogin},
  Cdm in 'Cdm.pas' {Dm: TDataModule},
  CSysSetup in 'CSysSetup.pas' {fmSysSetup},
  U_openproject in 'U_openproject.pas' {Frmopenproject},
  U_product in 'U_product.pas' {Frmproduct},
  U_provider in 'U_provider.pas' {Frmprovider},
  U_choosepart in 'U_choosepart.pas' {frmchoosepart},
  U_chooseproduct in 'U_chooseproduct.pas' {frmchooseproduct},
  U_Customers in 'U_Customers.pas' {frmCustomers},
  U_payment in 'U_payment.pas' {Frmpayment},
  U_selectpart in 'U_selectpart.pas' {frmselectpart},
  U_changepassword in 'U_changepassword.pas' {Frmchangepassword},
  U_stockmanage in 'U_stockmanage.pas' {frmstockmanage},
  U_help in 'U_help.pas' {frmhelp},
  U_select in 'U_select.pas' {Frmselect},
  U_printstock in 'U_printstock.pas' {Frmprintstock},
  U_users in 'U_users.pas' {frmUsers},
  U_newproject in 'U_newproject.pas' {Frmnewproject},
  U_selectcp in 'U_selectcp.pas' {Frmselectcp},
  U_createorder in 'U_createorder.pas' {Frmcreateorder},
  U_modifynum in 'U_modifynum.pas' {Frmmodifynum},
  U_selectsupplier in 'U_selectsupplier.pas' {frmselectsupplier},
  U_stoctinout in 'U_stoctinout.pas' {Frmstockinout},
  U_stockselect in 'U_stockselect.pas' {Frmstockselect},
  U_shouldpay in 'U_shouldpay.pas' {Frmshouldpay},
  U_projectsel in 'U_projectsel.pas' {Frmprojectsel},
  U_receive in 'U_receive.pas' {frmreceive},
  U_proselect in 'U_proselect.pas' {frmproselect},
  U_payprint in 'U_payprint.pas' {Frmpayprint},
  U_receiveprint in 'U_receiveprint.pas' {frmreceiveprint},
  U_balance in 'U_balance.pas' {frmbalance},
  U_balanceprint in 'U_balanceprint.pas' {frmbalanceprint},
  U_printorder in 'U_printorder.pas' {frmprintorder},
  U_balancetotalprint in 'U_balancetotalprint.pas' {frmbalancetotalprint},
  U_deleteproject in 'U_deleteproject.pas' {frmdeleteproject};{$R *.res}
var
  Hmutex :HWND ;
  Ret : Integer ;begin
  Application.Initialize;
  Hmutex := CreateMutex(nil,False,'IhomeOA');
  Ret := GetLastError;
   if Ret <> ERROR_ALREADY_EXISTS then
  begin
  Application.CreateForm(TDm, Dm);
  Application.CreateForm(TFrmmain, Frmmain);
  Application.CreateForm(Tfrmchoosepart, frmchoosepart);
  Application.CreateForm(Tfrmchooseproduct, frmchooseproduct);
  Application.CreateForm(TFrmpayment, Frmpayment);
  Application.CreateForm(Tfrmselectpart, frmselectpart);
  Application.CreateForm(TFrmchangepassword, Frmchangepassword);
  Application.CreateForm(Tfrmhelp, frmhelp);
  Application.CreateForm(TFrmselect, Frmselect);
  Application.CreateForm(TFrmprintstock, Frmprintstock);
  Application.CreateForm(TFrmselectcp, Frmselectcp);
  Application.CreateForm(TFrmmodifynum, Frmmodifynum);
  Application.CreateForm(Tfrmselectsupplier, frmselectsupplier);
  Application.CreateForm(TFrmstockselect, Frmstockselect);
  Application.CreateForm(TFrmprojectsel, Frmprojectsel);
  Application.CreateForm(Tfrmproselect, frmproselect);
  Application.CreateForm(TFrmpayprint, Frmpayprint);
  Application.CreateForm(Tfrmreceiveprint, frmreceiveprint);
  Application.CreateForm(Tfrmbalance, frmbalance);
  Application.CreateForm(Tfrmbalanceprint, frmbalanceprint);
  Application.CreateForm(Tfrmprintorder, frmprintorder);
  Application.CreateForm(Tfrmbalancetotalprint, frmbalancetotalprint);
  Frmlogin:= TFrmlogin.Create(Application);
    if Frmlogin.ShowModal = mrOk then
    begin
     Application.CreateForm(TFrmmain,frmmain);
     Application.Run;
    end
    else
    begin
     Application.ShowMainForm := False;
     Application.Terminate;
     Application.Run;
    end;
  end
  else begin
    ReleaseMutex(Hmutex);
    Application.MessageBox('程序已经启动，不能同时启动多个程序','启动程序',MB_OK+MB_ICONINFORMATION);
  end;
  end.