writing into config file

[E481610]

how to write values into app config files using c# code in windows forms applications

[Dheeraj Joshi]

config.AppSettings.Settings["newVal"].Value = "100";    
 

Regards
Dheeraj Joshi

[E481610]

hi
just now i have the the code
config.AppSetti ngs.Settings["newVal"].Value = "100";
for writing into app.config file
but the error it is showing is
"Object reference not set to an instance of an object."
can u please clarify my doubt?

[MrMancunian]

"Object reference not set to an instance of an object." means that you are referring to an object without a value. It can be solved by declaring the object as New. Can you post the code that gives you the error?

Steven

[Dheeraj Joshi]

Does "newVal" exists in app.config?

Regards
Dheeraj Joshi

To OP: Please do not start new thread when you have problem with same isuue. Continue posting in same thread. In this thread you asked how to write into app.config. Now you have problem in writing to it, so according to rules you need to post in same thread not to start new one.

[E481610]

hi i have written into the app config file by using the code
config.AppSetti ngs.Settings.Ad d("srinu","100" );
where "srinu" is the key , and "100" is its value
now what i want to do is........ i have to display those key and its value in two different text fields by the click of the button
can u please reply me fast?

[Dheeraj Joshi]

Get the value of the key from the app.config and display it.

Something like this

String myVal = System.Configuration.ConfigurationSettings.AppSettings["newVal"].toString();
 

Regards
Dheeraj Joshi

[E481610]

@dheerajjoshim
hi
the code u sent is for the key and value that were in app.config file
but what i want to retrieve is....to retrieve key and value that are externally written using some writing into app.config file codes
just check the code below

System.Configur ation.Configura tion config = ConfigurationMa nager.OpenExeCo nfiguration(Con figurationUserL evel.None);
/* XmlDocument doc =
XmlNode node = doc.SelectSingl eNode("//appSettings");*/
string c = config.AppSetti ngs.Settings["secondname "].Value = "100";
//string k =Keys(config.Ap pSettings.Setti ngs["govinda"].Value) = "modifiedvalue" ;
//config.AppSetti ngs.Settings.Ad d("Modification Date", DateTime.Now.To LongTimeString( ) + " ");
//textBox2.Text = c;
string[] keys = appSettings.All Keys;
config.AppSetti ngs.Settings.Ad d("srinu","100" );
config.Save(Con figurationSaveM ode.Modified);

String myVal = System.Configur ation.Configura tionSettings.Ap pSettings["100"].ToString();
textBox1.Text = keys[1];
textBox2.Text = myVal;

here "keys" is an array having only 2 values means upto keys[1] it exists
but when i give textBox1.Text = keys[2];
it is showing error eventhough i have written another "srinu" key into config file

[Dheeraj Joshi]

@E481610
What is the error?

Regards
Dheeraj Joshi

[Dheeraj Joshi]

String myVal = System.Configuration.ConfigurationSettings.AppSett ings["100"].ToString();
 

This is wrong it must be

String myVal=System.Configuration.ConfigurationSettings.AppSettings["secondname"].ToString();
 

Regards
Dheeraj Joshi