错误：类型 HTMLElement 上不存在属性“选择”

Question

 function copy(){
        var Url=document.getElementById("Id");
        Url.select(); //error
        document.execCommand("Copy"); // browser copy
        }

as above. I'm trying to make a function to copy text in browser.but the error as title occurred in typescript. the select() is valid I think( link ),since I can copy correctly when I use it in a demo. my ts version is 2.8.1

Answer 1

You need to add a type assertion :

var Url = document.getElementById("Id") as HTMLInputElement;
Url.select(); // OK

Reason

getElementById can return any HTMLElement s. In your case you know its an input element so you can tell TypeScript that by using a type assertion 🌹.

Answer 2

select method is defined for HTMLInputElement s. The following will get rid of the TypeScript error.

let Url: HTMLInputElement = document.getElementById("Id") as HTMLInputElement;
Url.select();
document.execCommand("Copy");

Answer 3

You need to specify the correct type of the element, because React thinks it's just an HTMLElement instead of HTMLInputElement.

So, change to it!

var Url=document.getElementById("Id") as HTMLInputElement;