So bearbeiten Sie die .csproj -Datei

The CSPROJ file, saved in XML format, stores all the references for your project 
including your compilation options. There is also an SLN file, which stores information 
about projects that make up your solution.

If you are using Visual Studio and you have the need to view or edit your CSPROJ file,
while in Visual Studio, you can do so by following these simple steps:

Right-click on your project in solution explorer and select Unload Project

Right-click on the project (tagged as unavailable in solution explorer) and 
click "Edit yourproj.csproj". This will open up your CSPROJ file for editing.
  
After making the changes you want, save, and close the file. Right-click again on 
the node and choose Reload Project when done.
Mappy Show