Question

How do I override and format string in ToString method to get multiline debug message, when I mouse over some variable in debuger. Currently when I return multiline string (seperated by \r\n), it still ends up in single line in debugger.

Answer 1

You could write a debugger visualizer for your type. Depending on your needs this might be overkill of course.

As @dtb has kindly noted in a comment, there is a visualizer provided out of the box which might be sufficent for your needs:

There’s a visualizer that shows text and honours line breaks. You can
access it from the magnifying glass icon in the tooltip. It’s just the
tooltip that shows strings in C# string literal syntax