问题
When casting in a .tsx file, the compiler assumes it to be JSX, e.g.:
(<HtmlInputElement> event.target).value
gives an error
JSX element type 'HtmlInputElement' is not a constructor function for JSX elements
How do you cast TypeScript in a .tsx file?
回答1:
The as operator was introduced to TypeScript 1.6 to replace casts in .tsx files, e.g.:
(event.target as HTMLInputElement).value
The TypeScript wiki explains the 1.6 changes: it makes the new as operator the default way to cast (removing any ambiguity between JSX expressions and the TypeScript prefix cast operator)
来源：https://stackoverflow.com/questions/37613981/how-to-use-a-typescript-cast-with-jsx-tsx