Edit and Continue (Visual C#)
With Hot Reload, or Edit and Continue for C#, you can make changes to your code in break or run mode while debugging. The changes can be applied without having to stop and restart the debugging session.
The basic Hot Reload experience works with most types of .NET apps and framework versions. This includes .NET Framework, .NET Core and .NET 5+ (for both C# and Visual Basic as applicable). The expectation in this scenario is that if you’re using the debugger, assume Hot Reload is available to you and give it a try!
Hot Reload supports most changes you might want to make during a debugging session, but there are some exceptions. For example, Hot Reload is not supported for optimized code or debugging sessions with the managed and native debugger enabled.
For information on other unsupported scenarios, see Supported code changes (C# and Visual Basic). If you try to apply code changes with one of these scenarios, a message box appears stating that Hot Reload is not supported.
Use Hot Reload
Hot Reload for C# happens automatically when you make code changes in break mode, then continue debugging by using Continue, Step, or Set Next Statement. If you set Hot Reload on file save to true, it will also happen automatically when saving a file.
To enable or disable Hot Reload:
If you're in a debugging session, stop debugging (Debug > Stop Debugging or Shift+F5).
Open Tools > Options > Debugging > .NET/C++ Hot Reload, select or clear the Enable Hot Reload and Edit and Continue when debugging check box.
The setting takes effect when you start or restart the debugging session.
To use the classic Edit and Continue experience:
While debugging, in break mode, make a change to your source code.
From the Debug menu, click Continue, Step, or Set Next Statement. Debugging continues with the new, compiled code.
Some types of code changes are not supported by Edit and Continue. For more information, see Supported code changes (C# and Visual Basic).
With Edit and Continue for C#, you can make changes to your code in break or run mode while debugging. The changes can be applied without having to stop and restart the debugging session. In run mode, the source editor is read-only.
Edit and Continue is supported in UWP in Windows 10 or later, and x86 and x64 apps that target the .NET Framework 4.6 desktop or later versions (the .NET Framework is a desktop version only).
Edit and Continue supports most changes you might want to make during a debugging session, but there are some exceptions. Edit and Continue is not supported for optimized, mixed, or SQL Server common language runtime (CLR) integration code. For information on other unsupported scenarios, see Supported code changes (C# and Visual Basic). If you try to Edit and Continue with one of these scenarios, a message box appears stating that Edit and Continue is not supported.
For information on other unsupported scenarios, see Supported code changes (C# and Visual Basic). If you try to apply code changes with one of these scenarios, a message box appears stating that Hot Reload is not supported.
Use Edit and Continue
Edit and Continue for C# happens automatically when you make code changes in break mode, then continue debugging by using Continue, Step, or Set Next Statement, or evaluate a function in a debugger window.
To enable or disable Edit and Continue:
If you're in a debugging session, stop debugging (Debug > Stop Debugging or Shift+F5).
In Tools > Options (or Debug > Options) > Debugging > General, select or clear the Enable Edit and Continue check box.
The setting takes effect when you start or restart the debugging session.
To use the Edit and Continue:
While debugging, in break mode, make a change to your source code.
From the Debug menu, click Continue, Step, or Set Next Statement, or evaluate a function in a debugger window.
Debugging continues with the new, compiled code.
Some types of code changes are not supported by Edit and Continue. For more information, see Supported code changes (C# and Visual Basic).