c# - BatteryStatusChange WMI event not being received -

i trying catch batterystatuschange event in wmi. when execute program, not battery events @ either when battery starts charging or discharging.

code trying out:

namespace batterystatuschange { class program {     static void main(string[] args)     {         try         {           wqleventquery query = new wqleventquery(                 "select * batterystatuschange");               managementscope scope = new managementscope(string.format("\\\\{0}\\root\\wmi", "localhost"), null);             scope.connect();              managementeventwatcher watcher = new managementeventwatcher(scope, query);             console.writeline("waiting event...");              managementbaseobject eventobj = watcher.waitfornextevent();              console.writeline("{0} event occurred.", eventobj["__class"]);              // cancel event subscription             watcher.stop();             return;         }         catch (managementexception err)         {             messagebox.show("an error occurred while trying receive event: " + err.message);         }     } } } 

when execute program, not battery events @ either when battery starts charging or discharging.

i have tried different query strings 1 below no avail:

select * batterystatuschange poweronline =  true 

any appreciated.

try using batterystatus wmi class instead.

try sample.

using system; using system.collections.generic; using system.management; using system.text;   namespace getwmi_info {     public class eventwatcherasync      {         private void wmieventhandler(object sender, eventarrivedeventargs e)         {             console.writeline("targetinstance.charging :             " + ((managementbaseobject)e.newevent.properties["targetinstance"].value)["charging"]);             console.writeline("targetinstance.description :          " + ((managementbaseobject)e.newevent.properties["targetinstance"].value)["description"]);             console.writeline("targetinstance.name :                 " + ((managementbaseobject)e.newevent.properties["targetinstance"].value)["name"]);             console.writeline("targetinstance.poweronline :          " + ((managementbaseobject)e.newevent.properties["targetinstance"].value)["poweronline"]);             console.writeline("targetinstance.remainingcapacity :    " + ((managementbaseobject)e.newevent.properties["targetinstance"].value)["remainingcapacity"]);             console.writeline("targetinstance.voltage :              " + ((managementbaseobject)e.newevent.properties["targetinstance"].value)["voltage"]);          }          public eventwatcherasync()         {             try             {                 string computername = "localhost";                 string wmiquery;                 managementeventwatcher watcher;                 managementscope scope;                      if (!computername.equals("localhost", stringcomparison.ordinalignorecase))                  {                     connectionoptions conn = new connectionoptions();                     conn.username  = "";                     conn.password  = "";                     conn.authority = "ntlmdomain:domain";                     scope = new managementscope(string.format("\\\\{0}\\root\\wmi", computername), conn);                 }                 else                     scope = new managementscope(string.format("\\\\{0}\\root\\wmi", computername), null);                 scope.connect();                  wmiquery ="select * __instancemodificationevent within 1 "+                 "where targetinstance isa 'batterystatus' ";                  watcher = new managementeventwatcher(scope, new eventquery(wmiquery));                 watcher.eventarrived += new eventarrivedeventhandler(this.wmieventhandler);                 watcher.start();                 console.read();                 watcher.stop();             }             catch (exception e)             {                 console.writeline("exception {0} trace {1}", e.message, e.stacktrace);             }          }          public static void main(string[] args)         {            console.writeline("listening {0}", "__instancemodificationevent");            console.writeline("press enter exit");            eventwatcherasync eventwatcher = new eventwatcherasync();            console.read();         }     } }