I have a directory named Resources in my WPF project and I have a Settings.json inside that directory. I want to read content from that fil
using (StreamReader r = new StreamReader(Application.StartupPath + @"/Resources/Settings.json"))
Since you've got your Build Action set to Embedded Resource, you probably want to use the Assembly.GetManifestResourceStream method.
For example:
using (Stream stream = assembly.GetManifestResourceStream("MyCompany.Namespace.Settings.json"))
using (StreamReader reader = new StreamReader(stream))
Directory.GetCurrentDirectory();