What is an annotation in C#?
What is an annotation in C#?
An annotation on a program element (commonly a class, method, or field) is a piece of meta-data added to that program element which can be used to embellish that element with extra code. In Java this is called an annotation, in C# this is called an attribute.
What is data validation in C#?
When you use the Data Annotations Model Binder, you use validator attributes to perform validation. The System. ComponentModel. DataAnnotations namespace includes the following validator attributes: Range – Enables you to validate whether the value of a property falls between a specified range of values.
Why attributes are used in C#?
Attributes are used in C# to convey declarative information or metadata about various code elements such as methods, assemblies, properties, types, etc. Attributes are added to the code by using a declarative tag that is placed using square brackets ([ ]) on top of the required code element.
How do C# attributes work?
In C#, attributes are classes that inherit from the Attribute base class. Any class that inherits from Attribute can be used as a sort of “tag” on other pieces of code. For instance, there is an attribute called ObsoleteAttribute . This is used to signal that code is obsolete and shouldn’t be used anymore.
How do I validate in C#?
Step 1: Create a Windows form application. Step 2: Choose “ErrorProvider” form toolbox. Step 3: Select the Text box and go to its properties. In properties choose “Events” and under focus double click on “validating”.
What is Route in MVC C#?
ASP.NET MVC routing is a pattern matching system that is responsible for mapping incoming browser requests to specified MVC controller actions. When the request’s URL matches any of the registered route patterns in the route table then the routing engine forwards the request to the appropriate handler for that request.
Can we use ViewState in MVC?
ASP.NET MVC does not use ViewState in the traditional sense (that of storing the values of controls in the web page). Rather, the values of the controls are posted to a controller method. Once the controller method has been called, what you do with those values is up to you.
Can structs inherit C#?
A structure type can’t inherit from other class or structure type and it can’t be the base of a class. However, a structure type can implement interfaces.
What are data annotations in a C # program?
Data Annotations are attributes which are applied to the class or members that specify validation rules, specify how the data is displayed, and set relationships between classes.
What do you need to know about DataAnnotations?
Specifies whether a class or data table uses scaffolding. Specifies the minimum and maximum length of characters that are allowed in a data field. Specifies the data type of the column as a row version. Specifies the template or user control that Dynamic Data uses to display a data field.
What are the names of the DataAnnotations namespace?
Specifies the data type of the column as a row version. Specifies the template or user control that Dynamic Data uses to display a data field. Provides URL validation. Serves as the base class for all validation attributes. Describes the context in which a validation check is performed.
How are DataAnnotations used in ASP.NET Dynamic Data?
Specifies how data fields are displayed and formatted by ASP.NET Dynamic Data. Indicates whether a data field is editable. Validates an email address. Enables a .NET enumeration to be mapped to a data column. Validates file name extensions. Represents an attribute that is used to specify the filtering behavior for a column.