Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Help Me

Posted on 2016-11-08
6
Medium Priority
?
88 Views
Last Modified: 2016-11-27
object AppWorkspace = null;
            MainForm.DefaultBackColor.Equals(AppWorkspace);
MainForm mf = new MainForm();
            mf.Show();
this is supposed to change the BackColor in MainForm

Getting ready for sulotions
0
Comment
Question by:Brian Smith
6 Comments
 
LVL 22

Assisted Solution

by:p_davis
p_davis earned 1000 total points (awarded by participants)
ID: 41879551
you aren't setting the background color in this. equals is a boolean check
1
 
LVL 22

Accepted Solution

by:
p_davis earned 1000 total points (awarded by participants)
ID: 41879554
if this is winforms use the properties of the form to change the color
0
 
LVL 2

Assisted Solution

by:weifai
weifai earned 500 total points (awarded by participants)
ID: 41879562
The Equals() methods are usually not for setting the property, but to compare it to the parameter and return a boolean value.

Also, you should involve your form, not the form's class.

It should be something like
mf.BackColor = new Color(...);

Open in new window

right after creating mf and before showing it.
0
Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

 
LVL 35

Assisted Solution

by:it_saige
it_saige earned 500 total points (awarded by participants)
ID: 41879595
What p_davis is saying is that .Equals() is a comparison method.  It checks to see if two objects are equal to each other and returns a boolean value that indicates if they are Equal to each other.  Think of .Equals() as being directly related to '==' but with subtle differences:
The Equals method is just a virtual one defined in System.Object, and overridden by whichever classes choose to do so. The == operator is an operator which can be overloaded by classes, but which usually has identity behaviour.

For reference types where == has not been overloaded, it compares whether two references refer to the same object - which is exactly what the implementation of Equals does in System.Object.

Value types do not provide an overload for == by default. However, most of the value types provided by the framework provide their own overload. The default implementation of Equals for a value type is provided by ValueType, and uses reflection to make the comparison, which makes it significantly slower than a type-specific implementation normally would be. This implementation also calls Equals on pairs of references within the two values being compared.

- Source

Regardless, in C#, Equals and '==' are not the same as '=' which is the assignment operator.

Consider the following:
using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

namespace EE_Q28981881
{
	class Program
	{
		static void Main(string[] args)
		{
			Person bob = new Person() { ID = 1, FirstName = "Bob", LastName = "Smith" };
			Console.WriteLine("The original bob");
			Console.WriteLine(bob);
			Person bob2 = bob.Clone();
			Console.WriteLine("The cloned bob");
			Console.WriteLine(bob2);
			Console.WriteLine();
			Console.WriteLine("Are the orginal bob and the cloned bob equal? {0}", bob == bob2);
			Console.WriteLine();
			Console.WriteLine("Let's change the cloned bob's last name.");
			bob2.LastName = "Johnson";
			Console.WriteLine("The cloned bob");
			Console.WriteLine(bob2);
			Console.WriteLine("Are the orginal bob and the cloned bob equal? {0}", bob == bob2);
			Console.ReadLine();
		}
	}

	[Serializable]
	class Person
	{
		public int ID { get; set; }
		public string FirstName { get; set; }
		public string LastName { get; set; }

		public override string ToString()
		{
			return string.Format("{0} {1} [{2}]", FirstName, LastName, ID);
		}

		public override bool Equals(object obj)
		{
			if (obj == null || (obj.GetType() != GetType()))
				return false;

			return this == (obj as Person);
		}

		public bool Equals(Person person)
		{
			if (object.ReferenceEquals(person, null))
				return false;

			return this == person;
		}

		public override int GetHashCode()
		{
			return (ID != null ? ID.GetHashCode() : 0) ^ (FirstName != null ? FirstName.GetHashCode() : 0) ^ (LastName != null ? LastName.GetHashCode() : 0);
		}

		public static bool operator ==(Person lhs, Person rhs)
		{
			if (object.ReferenceEquals(lhs, rhs))
				return true;

			if (object.ReferenceEquals(lhs, null) || object.ReferenceEquals(rhs, null))
				return false;

			return (lhs.ID != null && rhs.ID != null ? lhs.ID.Equals(rhs.ID) : false) &&
				(lhs.FirstName != null && rhs.FirstName != null ? lhs.FirstName.Equals(rhs.FirstName) : false) &&
				(lhs.LastName != null && rhs.LastName != null ? lhs.LastName.Equals(rhs.LastName) : false);
		}

		public static bool operator !=(Person lhs, Person rhs)
		{
			return !(lhs == rhs);
		}
	}

	static class Extensions
	{
		public static T Clone<T>(this T source)
		{
			if (!typeof(T).IsSerializable)
				throw new ArgumentException("The type to be cloned must be serializable.", "source");

			if (object.ReferenceEquals(source, null))
				return default(T);

			IFormatter formatter = new BinaryFormatter();
			using (Stream stream = new MemoryStream())
			{
				formatter.Serialize(stream, source);
				stream.Seek(0, SeekOrigin.Begin);
				return (T)formatter.Deserialize(stream);
			}
		}
	}
}

Open in new window

Which produces the following output -Capture.JPG
-saige-
0
 
LVL 30

Expert Comment

by:anarki_jimbel
ID: 41879755
Could you please explain clearly what you want to achieve?

1. Guys above explained already that ".Equals" is just a check if something equals to something, therefore it won't change the color.

2. Setting color 2 null won't probably give any effect. How you imagine "null color"?
0
 
LVL 30

Expert Comment

by:anarki_jimbel
ID: 41902972
Solution is provided
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction Although it is an old technology, serial ports are still being used by many hardware manufacturers. If you develop applications in C#, Microsoft .NET framework has SerialPort class to communicate with the serial ports.  I needed to…
This article is for Object-Oriented Programming (OOP) beginners. An Interface contains declarations of events, indexers, methods and/or properties. Any class which implements the Interface should provide the concrete implementation for each Inter…
This Micro Tutorial will teach you how to add a cinematic look to any film or video out there. There are very few simple steps that you will follow to do so. This will be demonstrated using Adobe Premiere Pro CS6.
this video summaries big data hadoop online training demo (http://onlineitguru.com/big-data-hadoop-online-training-placement.html) , and covers basics in big data hadoop .

877 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question