javascript - HTMLCollection[] 未定义

Question

rowGetter = i => {
    const row = this.state.estimateItemList[i];
    const selectRevison = this.state.selectedEstimate.revision;
    const rowLenght = this.state.estimateItemList.length;
    const changeColor = document.getElementsByClassName('rd') as 
    HTMLCollectionOf<HTMLElement>;
    if (row.revision > selectRevison) {
        for (let x = 0; x < changeColor.length; x++) {
            row.changeColor.style.backgroundColor = 'red';
            // changeColor.style.backgroundColor = 'red'; //this is get error(Cannot read property 'style' of undefined)
        }
        return row;
    }
}

我想在条件 row.revision > this.state.selectedEstimate.revision 时更改行颜色。如何防止 this.color 发生变化。但是我没有收到任何错误，但行颜色没有改变，并且 changeColor : HTMLCollection [] 没有得到任何项目。它始终是未定义。我该如何解决这个问题？

Answer 1

你能试试这个吗:

const changeColor = document.getElementsByClassName('rd');

而不是:

const changeColor = document.getElementsByClassName('rd') as HTMLCollectionOf;