1.用findwindow
2.function CheckIsFirst:Boolean;
begin
fMutexHandle:=OpenMutex(mutex_all_access,False,'a_program_name');
if fMutexHandle=0 then
begin
fMutexHandle:=CreateMutex(nil,false,'a_program_name');
result:=fMutexHandle<>0;
end else
begin
Result:=False;
TUtils.ShowMess('程序已经运行,不允许两个实例同时运行!');
end;