Does Blazor have an enum-typed equivalent of WinForms' Keys for KeyboardEventArgs?-CodePudding

.NET Core's KeyboardEventArgs class contains the Key and Code properties, which are both strings. So I must use magic strings like if (e.Key == "Backspace") { }.

.NET Framework (and the current Desktop API) have the System.Windows.Forms.Keys enum, which allows us to write code without magic strings, e.g. if (e.Key == Keys.Back) { }.

Is there an equivalent enum for .NET Core? I want this for a Blazor app.

CodePudding user response：

The KeyboardEventArgs you're referring to is Blazor's own Microsoft.AspNetCore.Components.Web.KeyboardEventArgs which is the Blazor view of the DOM's KeyboardEvent.

While the DOM's KeyboardEvent does have integer (number in JS)-typed members, these are all either obsolete, non-standard or only ever seen in draft specs, and/or have values that vary between browsers and/or OS families, which makes them non-portable and so it's no surprise that Blazor doesn't use them.

Of the myriad proprietary and draft members of KeyboardEvent DOM interface, only code and key are still defined in the current draft DOM UI Events specification and draft DOM Level 3 Events specification, all other key/char-indicator members are obsolete. I've made this table to list those members:

`KeyboardEvent` property	Type	Printable	Nonprintable	Status	Notes
`char`	`string`	True	False	Obsolete
`charCode`	`number`	True	False	Obsolete	Only used in `keypress` event (not `keydown`, etc). Returns ambiguous results in many cases.
`code`	`string`	True	True	Current
`key`	`string`	True	True	Current
`keyIdentifier`	`string`	True	True	Obsolete	Proprietary to Apple Safari/WebKit.
`keyCode`	`number`	False	True	Obsolete
`which`	`number`	True	True	Obsolete	Inherited from `UIEvent`. Aliases `charCode` for printable chars, or `keyCode` for nonprintable chars.

Consider that C#'s enum-types are all integer-based: as of C# 11 in 2022 there is no concept of a String-based enum type which, which means if you (or the Blazor dev team) did want an enum-based member of Blazor's KeyboardEventArgs then you (or they) would have to manually maintain a mapping between KeyboardEvent.code/key string values and their enum members, which would be a huge PITA to maintain, especially given that as of October 2022 the DOM UI Events spec is still in the draft stage.