Denotes one or more properties that uniquely identify an entity. For example, in ASP.NET MVC, when a model is received by a controller method, ModelState.IsValid () can be used to tell if the received model respects all its ValidationAttribute. Microsoft makes no warranties, express or implied, with respect to the information provided here. We will study the list of validation attributes available. For simplicity going forward, the proposal will use the name Length to represent Count or Length. Specifies the maximum length of array or string data allowed in a property. For example: The language will provide an instance indexer member with a single parameter of type Range for types which meet the following criteria: For such types, the language will bind as if there is an indexer member of the form T this[Range range] where T is the return type of the Slice method including any ref style annotations. The content you requested has been removed.