oneinst.pas

一个漂亮的电子书籍阅读管理器

unit OneInst;

interface

uses
  Windows, SysUtils, Forms;

function CheckInstance:boolean;

implementation


var
  MyAppName, MyClassName: array[0..255] of Char;
  NumFound: Integer;
  LastFound, MyPopup: HWND;

function LookAtAllWindows(Handle: HWND; Temp: LongInt): BOOL; stdcall;
var
  WindowName, ClassName: Array[0..255] of Char;
begin
  if (GetClassName(Handle, ClassName, SizeOf(ClassName)) > 0) and
     (StrComp(ClassName, MyClassName) = 0) and
     (GetWindowText(Handle, WindowName, SizeOf(WindowName)) > 0) and
     (StrComp(WindowName, MyAppName) = 0) then
  begin
    Inc(NumFound);
    if Handle <> Application.Handle then LastFound := Handle;
  end;
  Result:= True;
end;

function CheckInstance:boolean;
begin
  Result:=false;
  NumFound := 0;
  LastFound := 0;
  GetWindowText(Application.Handle, MyAppName, SizeOf(MyAppName));
  GetClassName(Application.Handle, MyClassName, SizeOf(MyClassName));
  EnumWindows(@LookAtAllWindows, 0);
  if NumFound> 1 then
  begin
    MyPopup := GetLastActivePopup(LastFound);
    BringWindowToTop(LastFound);
    if IsIconic(MyPopup)
      then ShowWindow(MyPopup, SW_RESTORE)
      else SetForegroundWindow(MyPopup);
    Application.Terminate;
    Result:=true;
  end
end;

end.