Question

Is there a way to enter debug mode when a certain condition is met?

For example let’s say I would want to enter debug mode on the line on which i == 1 becomes true:

using System;

namespace ConditionalDebug
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var r = new Random();
            var i = r.Next(2);
            i += r.Next(2);
            i += r.Next(2);
            i += r.Next(2);
            i += r.Next(2);
            i = 1;
            Console.WriteLine(i);
        }
    }
}

I know it is possible to set conditional breakpoints like:

But of course I couldn’t use that since I would have to add a conditional breakpoint for each line in the code where the condition value might get changed and that would get very messy in a real application.

So, is there a way to globally set the condition i == 1 so that the debugger will break on the line on which the condition is met?

Thanks for your help!

Answer 1

The short answer is ‘No’

The long answer is ‘Not really, but kinda’. There are things you can do to get close to the behaviour you want.

• You can use the Watch window and manually step through code and see it change.
• You can find all references on the variable and isolate all the statements that can change your variable and place break points.
• You could do the above, but use a wrapper function (or make it a Property) and only set the variable’s value through that function (or property setter) then you have a single point where you can set your conditional break-point to compare the old/new value.
• You could put a break point on EVERY line and set the condition for all of them at once. You might be able to automate that by writing a VS Plug-in or Macro.
• It’s beyond me – but I’m sure it is possible to do something amazingly complex and awesome like write your own debugger and implement your ‘Break whenever X Changes’.