Check setting exists in web.config

Question

How do I check a setting exists in the web.config file?

I found the following code, however i think it is aimed at an app.config file? where as my settings are in web.config. The below code returns no keys even though there are 6.

 if (ConfigurationManager.AppSettings.AllKeys.Contains(settingName))
 {
     return 1;
 }
 else
 {
      return 0;
 }

Example settings in web.config:

<configuration>
  . . .
  <applicationSettings>
    <ProjectNameSpace.Properties.Settings>
    <setting name="mySetting" serializeAs="String">
       <value>True</value>
     </setting>
   </ProjectNameSpace.Properties.Settings>
  </applicationSettings>
</configuration>

Originally i was trying to read it out, and check if it errors or exists.

 var property = Properties.Settings.Default.Properties[settingName];

But that line of code seems to load from the web.config, and if it doesn't exist, it gets it from the project settings. So I cant tell if it is in the web.config or not by checking the value is blank, as it is set to something else!

Answer 1

How about setting the design time value to empty value?

if(string.IsNullOrEmpty(Properties.Settings.Default.mySetting))
{
  // not set in web.config 
}
else
{
 // set in web.config and use it
}

Noe that if you set a value for the setting in web.config and later when you open project's settings file, it attempts to synchronize the value to match web.config value.