Описание тега selectlistitem
Refers to the SelectListItem class used to generate html <option> elements in a view associated with the ASP.NET MVC framework
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In ASP.NET MVC views, the DropDownListFor method is typically used to create a HTML <select> tag and its <option> elements. The SelectListItem class provides a convenient means of generating a collection in the controller to represent the options to generate in the <select> tag.
The Value property of SelectListItem sets the value attribute of the <option> tag and the Text property sets its inner text. Additional properties of SelectListItem can be used for selecting the option, disabling the option and grouping the option in <optgroup> elements.