sql server 2012 express - How to activate application roles using typed dataset in C#? -

i working in windows c# 2013 project has sql server 2012 express database, have created 3 application roles, use typed dataset in project, search way activate application role in project.

i found information not complete answers, made code not working, because event connection_statechange not fire, here code in class class1 in project put code:

public string rl, rlpss; //rl, rlpss variables contain role name , password.  public void setapprole(sqlconnection ta) {     if (ta.state==connectionstate.open)     {         ta.close();     }     ta.open();      ta.statechange += connection_statechange; }  void connection_statechange(object sender, statechangeeventargs e) {     if (e.originalstate==system.data.connectionstate.closed && e.currentstate==system.data.connectionstate.open)     {         system.data.sqlclient.sqlcommand scm = new sqlcommand();         scm.connection = (sqlconnection)sender;         scm.commandtext = "exec sp_setapprole '" + rl + "' , '" + rlpss + "'";         scm.executenonquery();     } } 

in login under btnlogin put code:

cl.setapprole((system.data.sqlclient.sqlconnection)tableadaptermanager.connection);  mdiparent1 md = new mdiparent1(); md.show(); 

i passed role name , password rl, rlpss.

i followed execution of code , found event connection_statechange not fired.

register event before change state

public void setapprole(sqlconnection ta   public void setapprole(sqlconnection ta)     {         ta.statechange += connection_statechange;         if (ta.state==connectionstate.open)         {             ta.close();         }         ta.open();       }