Question

I’d like to programmatically modify my app.config file to set which service file endpoint should be used. What is the best way to do this at runtime? For reference:

<endpoint address="http://mydomain/MyService.svc"
    binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_IASRService"
    contract="ASRService.IASRService" name="WSHttpBinding_IASRService">
    <identity>
        <dns value="localhost" />
    </identity>
</endpoint>

Answer 1

I think what you want is to swap out at runtime a version of your config file, if so create a copy of your config file (also give it the relevant extension like .Debug or .Release) that has the correct addresses (which gives you a debug version and a runtime version ) and create a postbuild step that copies the correct file depending on the build type.

Here is an example of a postbuild event that I’ve used in the past which overrides the output file with the correct version (debug/runtime)

copy "$(ProjectDir)ServiceReferences.ClientConfig.$(ConfigurationName)" "$(ProjectDir)ServiceReferences.ClientConfig" /Y

where :
$(ProjectDir) is the project directory where the config files are located
$(ConfigurationName) is the active configuration build type

EDIT:
Please see Marc’s answer for a detailed explanation on how to do this programmatically.