Part 7 - Advanced debugging using watch window

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Part 4 - Command window
Part 5 - Immediate window
Part 6 - Watch window



We discussed the basics of watch window in visual studio in Part 6. Please watch Part 6 before proceeding.



When the application is in debug mode and if we navigate to Debug - Windows - Watch, you will see that there are 4 watch windows.


Have you ever wondered the use of multiple watch windows?
Multiple watch windows are useful when you want to compare 2 object properties during debugging.

Let's understand their purpose with an example. Create a new console application with name = ConsoleApplication1. Copy and paste the following code.

using System;

using System.Collections.Generic;

namespace ConsoleApplication1

{

    class Program

    {

        static void Main()

        {

            List<Customer> customers = Customer.GetAllCustomers();

            foreach (Customer customer in customers)

            {

                Console.WriteLine("First Name = {0} & Last Name = {1}",

                    customer.FirstName, customer.LastName);

            }

        }

    }

    class Customer

    {

        public int ID { get; set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public string Gender { get; set; }

        public int Salary { get; set; }

        public static List<Customer> GetAllCustomers()

        {

            List<Customer> listCustomers = new List<Customer>();

            Customer customer1 = new Customer

            {

                ID = 101,

                FirstName = "Mark",

                LastName = "Scotts",

                Gender = "Male",

                Salary = 55000

            };

            Customer customer2 = new Customer

            {

                ID = 102,

                FirstName = "Steve",

                LastName = "Wicht",

                Gender = "Male",

                Salary = 45000

            };

            Customer customer3 = new Customer

            {

                ID = 103,

                FirstName = "Pam",

                LastName = "P",

                Gender = "Female",

                Salary = 65000

            };

            Customer customer4 = new Customer

            {

                ID = 104,

                FirstName = "Todd",

                LastName = "Snider",

                Gender = "Male",

                Salary = 45000

            };

            Customer customer5 = new Customer

            {

                ID = 105,

                FirstName = "Valarie",

                LastName = "Ward",

                Gender = "Female",

                Salary = 35000

            };

            listCustomers.Add(customer1);

            listCustomers.Add(customer2);

            listCustomers.Add(customer3);

            listCustomers.Add(customer4);

            listCustomers.Add(customer5);

            return listCustomers;

        }

    }

}

Place a breakpoint on the foreach loop in the Main() method and run the application in debug mode. When the application execution stops at the break point, open 2 watch windows by going to Debug - Windows - Watch menu.

In Watch 1 window, type customer[0] in Name column and press Enter key. Along the same lines in Watch 2 window, type customer[1] in Name column and press Enter key. Notice that now you have the opportunity 2 inspect 2 customer object properties.


Is it possible to get a copy of the object from one watch window to another watch window.
Yes, simply drag and drop. If you change a property of the object in one watch window, the change will be automatically reflected in the other watch window.

Is it possible to replace the current object instance with a new object instance
Yes, simply create a new object instance in immediate window. For example the Watch 1 window below displays the first customer object in customers collection.


To replace the current Customer object in customers[0] location. Open Immediate window by going to Debug - Windows - Immediate. Type the following command in Immediate window and press Enter key.
customers[0] = new Customer()

Notice that the Watch 1 windows now displays, the default values of the new Customer object that we have just created.