console application - app.config modify value c# -

the question addressed here app.config change value

the accepted answer is

string apppath = system.io.path.getdirectoryname(reflection.assembly.getexecutingassembly().location);           string configfile = system.io.path.combine(apppath, "app.config");  execonfigurationfilemap configfilemap = new execonfigurationfilemap();          configfilemap.execonfigfilename = configfile;            system.configuration.configuration config = configurationmanager.openmappedexeconfiguration(configfilemap, configurationuserlevel.none); config.appsettings.settings["yourthing"].value = "new value";  config.save();  

but when tried implement same, found weird behavior. above answer throws nullreferenceexception when setting value. config.appsettings.settings count zero.

so set configfile path app.config path inside project

string configfile = @"d:\app\schedule\schedule\app.config"; 

this modifies both app.config inside project << appname >>.exe.config in bin/debug. don't think feasible solution application can deployed on path. hard coding configpath not work.

then again modified configfile given

string configfile = system.io.path.combine(apppath, "<appname>.exe.config"); 

the above code runs , modifies << appname >>.exe.config , not app.config inside project.

i not sure correct or missing thing.

i on vs 2012, c# 4.5 , console application. of there no other code in console , app.config

<configuration>     <startup>          <supportedruntime version="v4.0" sku=".netframework,version=v4.5" />     </startup>     <appsettings>         <add key="yourthing" value="" />     </appsettings> </configuration> 

this wrong understanding of app.config. expecting application modify source code incorrect.

when run program creates copy of app.config bin/debug or bin/release folder.

your second solution fine. application working expected.