Create app config file if doesn't exist C#

Question

When I try to open my app config file by

ConfigurationManager.OpenExeConfiguration(filePath);

it returns an exception, because there is no file. But I need to create this file in this case. But as I know, config file create by adding at VS like How to: Add an Application Configuration File to a C# Project

So, how to create this file in other way?

Answer 1

If you really want to create an empty config file at runtime you can do something like this, but note that if the config file already exists this code will overwrite it:

System.Text.StringBuilder sb = new StringBuilder();
sb.AppendLine("<?xml version=\"1.0\" encoding=\"utf-8\" ?>");
sb.AppendLine("<configuration>");
sb.AppendLine("</configuration>");

string loc = Assembly.GetEntryAssembly().Location;
System.IO.File.WriteAllText(String.Concat(loc, ".config"), sb.ToString());

Answer 2

Just go to App.config file properties and change Copy to Output Directory setting from Do not copy to Copy always (or Copy if newer). That will automatically create config file during project build.