c# - SetAccessControl giving error as An unhandled exception of type 'System.UnauthorizedAccessException' occurred in mscorlib.dll -

i need set access control folder

my code

 private sub cmdapplyrestrictions_click(sender object, e eventargs) handles cmdapplyrestrictions.click     dim mydirectoryinfo new directoryinfo(txtfolder.text)      dim mydirectorysecurity directorysecurity = mydirectoryinfo.getaccesscontrol()     dim user string = system.environment.userdomainname + "\" + cmbuser.selecteditem.tostring()      mydirectorysecurity.addaccessrule(new filesystemaccessrule(user, filesystemrights.read, accesscontroltype.deny))     mydirectoryinfo.setaccesscontrol(mydirectorysecurity)     messagebox.show("permissions altered successfully")  end sub  

the line

mydirectoryinfo.setaccesscontrol(mydirectorysecurity) 

is giving exception

an unhandled exception of type 'system.unauthorizedaccessexception' occurred in mscorlib.dll

i logged in user administrative rights not administrator need block access users including logged in user user including administrator

later when program ends, restore permissions

one more requirement wish grant access folder 1 external program

you need app executed elevated privileges.

add app.manifest file app content:

<?xml version="1.0" encoding="utf-8"?> <asmv1:assembly manifestversion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv1="urn:schemas-microsoft-com:asm.v1" xmlns:asmv2="urn:schemas-microsoft-com:asm.v2" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance">   <assemblyidentity version="1.0.0.0" name="myapplication.app"/>   <trustinfo xmlns="urn:schemas-microsoft-com:asm.v2">     <security>       <requestedprivileges xmlns="urn:schemas-microsoft-com:asm.v3">         <requestedexecutionlevel level="requireadministrator" uiaccess="false" />       </requestedprivileges>     </security>   </trustinfo> </asmv1:assembly>