What does the [] represent in C# [duplicate] - c#

This question already has answers here:
What are attributes in .NET?
(11 answers)
Closed 9 years ago.
i've been developing in c# for 4 month and I still dont know what does the [] means in entity framework.
Here an example
[Column("mycolumn")]
public int Column {get;set;}
What is it functionality?
Its there another situation that i have to use it or just with entity framework?

Square brackets [ & ] mean a few different things in C#, but in this case they are saying that "Column" is an Attribute. An attribute is basically design time information that you add to classes or properties for various reasons. You can also make your own ;)

Related

What are [..] called above enum / class definition? [duplicate]

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What does the [Flags] Enum Attribute mean in C#?
(14 answers)
What does square bracket [] mean in the below code?
(2 answers)
what is [] brackets in .net? [duplicate]
(7 answers)
Closed 6 years ago.
Sorry for the silly question, but I came across the following C# code and I'm wondering what the [Flags] portion is and what it does.
[Flags]
public enum UserFlags
{
//...
}
Thank you in advance.
It's a class attribute. There are also method attributes for example.
You can even write your own
They are usually used to define meta information or behaviour about a class or method and can be read using reflection.

How to create custom keywords C# [duplicate]

This question already has answers here:
Is there a way to implement custom language features in C#?
(6 answers)
Closed 6 years ago.
I'm writing a library for personal use that greatly expands C# features, and I was wondering on something quite interesting... Is it possible to create you own keywords? For example, if, foreach, for etc.
The reason I want to do this can be found at my previous question.
No, you can not do that. Language keywords are defined in the language definition. You could probably use the open sourced parts (compilers, etc) and create your own version of them.

JSON field's names in the Web Service response [duplicate]

This question already has answers here:
Serializing F# Record type to JSON includes '#' character after each property
(2 answers)
Closed 7 years ago.
I use F#, but I believe the question is not F# specific.
I have the interface for Web Service:
[<ServiceContract>]
type IRestService =
[<OperationContract>]
[<WebGet(UriTemplate = "Maintenance", ResponseFormat=WebMessageFormat.Json)>]
abstract GetMaintenancesRest: a:unit -> Maintenance[]
When I am trying to use this service I can get JSON, but all field's names in the JSON have the symbol '#':
[{"Address#":"one","Assetid#":"","Assignmentdate#":"/Date(1434147917730-0700)/","Comment#":"" ...
Why and how can I fix it?
It's F#. I ran into this a long time ago, so I might be forgetting. As I recall you may not use records to return from the service, or you get this error. You need class types with properties. I don't think mutable records work either. I also don't think public fields work; it's got to be public read/write properties.

Difference between ContentPropertyAttribute and ContentProperty [duplicate]

This question already has answers here:
What's the difference between [Something] and [SomethingAttribute] [duplicate]
(3 answers)
Closed 7 years ago.
I hope this wasn't asked already. But i found nothing. If something exists, thanks for the note.
The title says it all i think.
I've seen these two variants. But in my opinion it does the same. And why can i use both. Thanks for education.
// variant 1
[ContentProperty("Text")]
// variant 2
[ContentPropertyAttribute("Text")]
You can omit the word "Attribute" when writing attributes over something. The actual class is called ContentPropertyAttribute. Both of your lines do exactly the same and use the exact same attribute class.

Significance of text inside square brackets [duplicate]

This question already has answers here:
What does square bracket [] mean in the below code?
(2 answers)
Closed 8 years ago.
Hello, can you please explain me what is the significance of [Microsoft.Xrm.Sdk.AttributeLogicalNameAttribute("activityid")] in the following code?
[Microsoft.Xrm.Sdk.AttributeLogicalNameAttribute("activityid")]
public Microsoft.Xrm.Sdk.EntityReference ActivityId
{
get
{
return this.GetAttributeValue<Microsoft.Xrm.Sdk.EntityReference>("activityid");
}
set
{
this.OnPropertyChanging("ActivityId");
this.SetAttributeValue("activityid", value);
this.OnPropertyChanged("ActivityId");
}
}
I searched for this thing and I got many posts which gave me answer as the ones in square brackets are Attributes in C#. But, then attributes are related with methods. Over here, ActivityId doesn't seem to be a method. So, how can [Microsoft.Xrm.Sdk.AttributeLogicalNameAttribute("activityid")] act as an attribute?
Is it related to C# or it has got something to do with CRM?
The confusion comes from your statement about attributes only being valid on methods. Attributes can be valid on items specified in the AttributeTargets enum:
http://msdn.microsoft.com/en-us/library/system.attributetargets.aspx
This then puts you back to the answer being "they are attributes". That attribute has simply been applied to a property.

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