Updating app.config via xpath

Earlier I raised this question: Get attribute value from c#/xpath

And the suggestions worked. However, I now need to update the actula document with a new value. I've tried to set the value property but this does not update the xml document (app.config in t开发者_开发问答his case). What would be the way to update an app.config?

Thanks

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You'll want to open it with ConfigurationManager.OpenExeConfiguration

From there you probably should use the methods of the configuration object to change the settings, followed by a Save to save it to disk. But, if you really want to use the XPath methods, you could check the FilePath property and swap to munging it with xml tools.