Is it possible to initialize a property change value?

Question

I'm newer to MVVM design pattern , I have a class User and a property IsEnabled,

I will use this class later in a ViewModel , what I would like to know if is it possible to initialize a property change in this class ( As an example Set IsEnabled to True )

 public  class User : INotifyPropertyChanged
    {
        public int UserId { get; set; }
        public string UserName { get; set; }
 public event PropertyChangedEventHandler PropertyChanged;

        private bool isEnabled;
        public bool IsEnabled
        {
            get { return isEnabled; }
            set
            {
                if (isEnabled != value)
                {
                    isEnabled = value;
                    OnPropertyChanged("IsEnabled");
                }
            }
        }
        protected void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null) 
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

The class compiles without any errors :

Maybe I misunderstood your question, but just write `IsEnabled = true` — SomeBody, Sep 27 '21 at 09:03
Does this code really compile? The class member isEnabled and the property have the same name. — Christopher Hamkins, Sep 27 '21 at 09:16
In my c# version I get an error message on the property isEnabled: "Member isEnabled is already defined" — Christopher Hamkins, Sep 27 '21 at 09:21
If you just need a different default value of the property, just declare `private bool isEnabled = true;` — Clemens, Sep 27 '21 at 09:22
@ChristopherHamkins, please check your code and remove the unvote . — csharp_devloper31, Sep 27 '21 at 09:24
@Clemens, and is it possible to change it , because in my case I need it for the binding and I need to set it in some other cases. — csharp_devloper31, Sep 27 '21 at 09:25
Set it when you create a User, like `var user = new User { IsEnabled = true };` — Clemens, Sep 27 '21 at 09:29
How can you have a class member and a property with the same name? Is this a new feature some c# version? (btw downvotes are not from me) — Christopher Hamkins, Sep 27 '21 at 11:18
There is no duplication , its just capitalization difference , I saw many examples of using propertychange with this method ( define private attribute start with lowercase and public attribute start with uppercase ) . — csharp_devloper31, Sep 27 '21 at 13:06
See the answer of this question : https://stackoverflow.com/questions/2246777/raise-an-event-whenever-a-propertys-value-changed — csharp_devloper31, Sep 27 '21 at 13:07
You should implement a constructor to initilaize your properties. — BionicCode, Sep 27 '21 at 13:16
@BionicCode , maybe this can be a solution , I also get it worked using the suggesstion of Clemens — csharp_devloper31, Sep 27 '21 at 13:17
Personally, I prefer to set the private backer to a value as Clemens suggests rather than set the property or backer in the ctor. You can see the default value easier. I might want to do other things in a ctor. You particularly want to ensure collections have a value initially because binding itemssource to a null collection initially will mean you never see any data in your control. Easier to double check if it's on the backer. — Andy, Sep 27 '21 at 14:13

score 0 · Accepted Answer · answered Sep 27 '21 at 15:11

0

Change the declaration of your backing property:

private bool isEnabled = true;

Then the initial value as applied to the DataContext and thus to any Binding extensions will propagate the true value.

answered Sep 27 '21 at 15:11

Andrew H

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This is just a copy of clemens comment. – Andy Sep 27 '21 at 17:33
I didn't copy any comments. I provided a simple solution to a straightforward problem. – Andrew H Sep 27 '21 at 17:39
@Andy comments are not for answering questions. I don't understand the logic of some users choosing to answer questions in comments when it completely misses the purpose of comments to ask for clarification from the asker. It's unfair to criticize me for posting a solution any developer could have come up with because I chose to use the correct avenue for posting that answer after someone else who didn't. – Andrew H Sep 27 '21 at 23:20
Some questions are trivial. They shouldn't really be question at all. The obvious answer to this is just set the field. That's one line. Some questions you have to just guess what the poster means. Ask them to explain or qualify as much as you like and they don't. – Andy Sep 28 '21 at 08:04
You're right, they may be trivial and they probably shouldn't be a question, but we're still here discussing the answer to such a trivial question :) I did not read through 10+ comments on such a simple question to find an identical answer and feel the selfish need to copy someone else's answer. I provided the answer any other semi-experienced developer would have provided, regardless of whether someone else incorrectly provided the answer as a comment. – Andrew H Sep 28 '21 at 16:20

Is it possible to initialize a property change value?

1 Answers1